## 1. Three Models of Temporal Consciousness


### 1.1 Time and Consciousness



Time and consciousness are interwoven on several levels. From the
vantage point of ordinary life and common sense, consciousness plainly
seems to exist *in* time. When we hear the clock strike twelve,
our auditory experience of it so doing also occurs at twelve (or at
most a few moments later). Watching a 120-minute action movie results
in a two hour stream of auditory and visual experiences (along with
accompanying thoughts and feelings), and this stream runs concurrently
with the playing of the movie. Quite generally, our conscious states,
irrespective of their kind or character, seem to occur in the same
temporal framework as events in the wider world. But this is by no
means the whole story.



There are also ways in which time or temporality might be regarded as
manifest *within* consciousness. We can judge the duration of
temporal intervals, particularly short ones, with reasonable
accuracy--an ability that psychologists have investigated in
considerable detail (see Wearden 2016 for an overview). Our episodic
(or autobiographical) memories supply us with access to our own pasts;
thanks to such memories our earlier states of consciousness are not
altogether lost to us: they can be recreated (or relived), albeit
imperfectly, in our present consciousness. And of course there are
past-oriented emotions, such as remorse or regret or shame: through
these the past can influence our present feelings, often in powerful
ways. While there is no future-directed counterpart of memory, we can
anticipate future happenings (more or less accurately, more or less
eagerly), and experience future-directed emotions: fear, dread,
hope--and these too can exert a powerful influence of our present
states of consciousness.



The story is still by no means complete, for temporality is manifest
in consciousness in a further and more intimate way. In our ordinary
experience, over brief intervals, we seem to be directly aware of
temporally extended phenomena such as change, persistence and
succession. When we see a friend waving goodbye, do we *infer*
that their arm is moving, on the basis of having observed a motionless
arm occupying a sequence of adjacent spatial location? We do make such
inferences of this kind: if I see that my neighbour's dustbin is
in the middle of the road rather than its usual position on the
pavement, I (rightly) infer that it has been moved. But the case in
question is not at all like this: what we see is simply an arm *in
motion*. (Is it for nothing that cinema is often called "the
moving image"?) The same applies in other sensory modalities.
When listening to a melody, we hear each note giving way to its
successor; when we hear a sustained violin tone, we *hear* the
tone continuing on, from moment to moment. If temporally extended
occurrences such as these can feature in our perceptual experience, it
is natural to conclude that our awareness must be capable of embracing
a temporal interval.



While this may seem obvious, it can also seem problematic. We can
remember the past and anticipate the future, but we are only directly
aware of what is present--or so it is natural to suppose. But the
present, strictly speaking, is momentary. So, if our awareness is
confined to the present, our awareness must itself lack temporal
depth. Hence, we are led swiftly to the conclusion that our direct
awareness cannot possibly encompass phenomena possessing temporal
extension. We are thus confronted with a conundrum: it seems our
awareness must extend over time, but it seems it can't.



In grappling with this "paradox of temporal awareness" as
it is sometimes called, different philosophers have proposed quite
different accounts (or models) of the structure of this form of
temporal consciousness. Simplifying somewhat, the most discussed
options fall into three main categories:


* **Cinematic Model:** our
experiences lacks any (or any significant) temporal
extension--they are akin to static, motion-free
"snapshots" or "stills". Our streams of
consciousness are composed of continuous successions of these static
conscious states. In this respect they are analogous to movies, which
(as displayed) consist of rapid sequences of still images.
* **Retentional Model:** our
experiencing of change and succession occurs within episodes of
consciousness which do not themselves possess any (or any significant)
temporal extension, but whose contents present (or represent)
temporally extended intervals and phenomena. These episodes thus have
a complex structure, comprising momentary phases of immediate
experience, along with representations (or *retentions*) of the
recent past. Our streams of consciousness are composed of successions
of states of this kind.
* **Extensional Model:** our
episodes of experiencing are themselves temporally extended, and are
thus able to incorporate change and persistence in a quite
straightforward way. Our streams of consciousness are composed of
successions of these extended phases of experience.




![link to extended description below](model-cinematic.svg)

a. Cinematic Model




![link to extended description below](model-retentional.svg)

b. Retentional Model




![link to extended description below](model-extensional.svg)

c. Extensional Model




Figure 1.1 The Three Main Conceptions of
Temporal Consciousness. [An
 extended description of Figure 1.1
 is in the supplement.]




In his influential writings on these matters William James argued that
to make sense of our temporal experience we need to distinguish the
*strict* or mathematical present from the *experiential*
or *specious* present: whereas the first is indeed
durationless, the second is experienced as possessing a brief
duration, sufficient to accommodate the change and persistence we find
in our immediate experience. Proponents of the cinematic model
maintain that James was mistaken: to make sense of our temporal
experience we don't need anything resembling an extended
specious present. Proponents of the extensional and retentional views
maintain that we *do* need something resembling a specious
present, but offer very different accounts of
 it.[1]



Ascertaining where the truth lies among the differing accounts of
temporal consciousness is interesting in itself. Although most forms
of experience seemingly feature succession and persistence--even
the most primitive forms if James was correct in characterizing infant
consciousness as a "blooming, buzzing
confusion"--many philosophers have not found it easy to
understand how any form of experience *can* have such
 features.[2]
 The interest and importance of the debate does not end here, for each
of the accounts of temporal awareness on offer has significant, and
very different, implications for our understanding of the general
structure of consciousness. In this entry we will be exploring the
principal features and motivations of the competing accounts, as well
as their strengths and
 weaknesses.[3]


### 1.2 Terminology, Problems and Principles



Although proponents of the competing approaches are attempting to make
sense of our experience of temporally extended phenomena, there are
divergences on the issue of how precisely this experience should be
construed and on several related matters.



One significant divide is between those who believe that temporally
extended phenomena really do figure in our immediate experience, and
those who deny this. To coin some terminology:




**Phenomeno-temporal Realism** (*PT-realism*,
henceforth further abbreviated to *realism*): change,
succession and persistence *can* be directly perceived or
apprehended.



**Phenomeno-temporal Antirealism**
(*PT-antirealism*, henceforth further abbreviated to
*antirealism*): change, succession and persistence
*cannot* be directly perceived or apprehended.




The extensional and retentional models are currently the two most
influential forms of realism, with both approaches being developed in
a variety of different ways. The task facing antirealists is in one
respect the easier of the two: unlike their realist counterparts, they
are under no obligation to provide an intelligible account of how it
is possible for our consciousness to embrace seemingly temporally
extended phenomena. But in another respect their task is the more
difficult. Antirealists are under an obligation to "save the
(temporal) phenomena": they need to supply a credible
explanation as to why so many of us find it so natural to *say*
we perceive movement and change if in fact we don't. After all,
it *does* seem perfectly natural to hold that we can see clouds
move across the sky, feel water flowing through our fingers and hear
melodies. This is the task facing those cinematic
theorists--e.g., Chuard (2017)--who hold that we do not
directly perceive change or succession but who also accept that we
seem to.



Realists generally maintain that it is important to distinguish the
experience *of* succession from a mere succession of
experiencings. An experience of succession involves a direct
experience of change or persistence; there is no guarantee that a
sequence of distinct momentary (or very brief) experiences will
constitute an experience with this character even if these experiences
occur successively and belong to the same person. If the experiencing
of a tone C and a tone D are two entirely separate experiential
episodes they won't jointly constitute an experiencing of the
succession C-being-followed-by-D. An experience *of* succession
involves a temporal spread of contents being presented
*together* in consciousness, albeit in the form of a perceived
succession rather than simultaneously.



In an influential treatment of these topics Izchak Miller (1984)
suggests that philosophical thinking on temporal consciousness has
been influenced--overtly or only covertly--by two
principles. Miller calls the first of these the "Principle of
Presentational Concurrence" (PPC), which he formulates thus:



> 
> 
> The duration of a content being presented is concurrent with the
> duration of the act of presenting it. That is, the time interval
> occupied by a content which is before the mind is the very same time
> interval which is occupied by the act of presenting that very content
> before the mind. (I. Miller 1984: 107)
> 
> 
> 



The "act-content" conception of the structure of
consciousness that Miller's formulation presupposes is not one
to which everyone will want to subscribe, but the basic thesis
encapsulated in PPC looks highly
 plausible.[4]
 If we watch a traffic light change from red to green it is natural to
think that we see the red light before we see the green light, and
that--more generally--our awareness of these events unfolds
concurrently with the events. Of the three conceptions of the nature
of temporal experience we encountered in
 SS1.1
 the extensional model most clearly conforms with PPC--and for
that reason has a *prima facie* plausibility.



Miller's second principle is less intuitively plausible, at
least on first acquaintance. Miller calls it the "Principle of
Simultaneous Awareness" (PSA):



> 
> 
> No succession of awarenesses--no matter how close together in
> time they come--can, by itself, account for an awareness of
> succession; it must be the case that an awareness of succession
> derives from simultaneous features of the structure of that awareness.
> For instance, an awareness of the succession of, say, two tones (or
> tone-qualities) must involve simultaneous awareness of both tones (or
> tone-qualities). (I. Miller 1984: 109)
> 
> 
> 



Some elements of Miller's formulation could be clearer. Phillips
expresses the basic idea more succinctly and more clearly:



**PSA:** If one is aware of a succession or duration, one
is necessarily aware of it at one moment. (2014b:
 140)[5]



If PSA is true our awareness of the traffic light changing from red to
green does *not* run concurrently with the event itself, it
occurs at a single moment, and so runs counter to PPC. To the extent
that PPC seems intuitively plausible, PSA seems implausible. However
despite this--as we shall see in
 SS4--an
 impressive number of philosophers and psychologists have rejected PPC
and subscribed to PSA. Why has the latter principle seemed plausible?
In part because it provides an answer to the question raised a moment
ago that many realists have found compelling: "How does an
experience of succession differ from a succession of
experiences?" For further discussion of these principles and
their motivations see Dainton (2000: SS5.6), Rashbrook (2013a),
Hoerl (2009), and Phillips (2010, 2014b).


### 1.3 Dynamics of Consciousness



There is a further issue which divides realists. In addition to
espousing different views as to the structures within consciousness
which provide us with temporal experiences, realists also defend a
range of different views concerning the *character* of temporal
experience. Think of what it is like to see ripples move across the
surface of a pond (or across one's skin), or an ocean wave
crashing on the beach, or the sound of a violin droning on. When we
carefully introspect, it becomes apparent that such experiences
possess an internal dynamic character, an immanent intrinsic directed
*flow*, of a distinctive kind. Since introspection also reveals
that inner experiences such as mental imagery and bodily sensations
all possess a flow-like character, there is reason to think this
special form of dynamism is a feature of all forms of temporal
experience. Or so some realists urge. Other realists are more
sceptical in this regard, and deny that experience is distinctively
dynamic in this sort of way, even if it is dynamic in other ways. We
thus have a further division to note:



**Strong dynamism**: some or all forms of consciousness
are imbued with an intrinsic directional flow-character.



**Moderate dynamism**: we directly experience change,
succession and persistence but our experience does *not*
possess the inherent flow-character posited by strong dynamists.



Bergson held that consciousness (or *duree*) is strongly
dynamic--"continual flow ... is the only immediate
date of consciousness" (Bergson 1889 [1910: 44]). He took this
dynamism to be a primitive or irreducible feature of experience,
describing the experience of a shooting star as "a line of
fire" that is characterized by an "absolutely indivisible
sensation of motion or mobility" (1889 [1910:
 111-2])[6]
 In stressing the process-like character of perceptual experience
Soteriou (2013) approvingly cites O'Shaughnessy, whose
commitment to strong dynamism is plain:



> 
> 
> [characteristically] the contents of experience are in flux, and
> necessarily experience itself is in flux, being essentially occurrent
> in nature ... [i]t is not the mere existence of flux [...]
> in the case of experience that is distinctive: it is the
> *necessity* of flux. (O'Shaughnessy 2000: 43)
> 
> 
> 



In his *Stream of Consciousness* (2000) Dainton maintains that
intrinsic flow and "dynamic patterning" are features of
our temporal experience, and he takes these features to be as
primitive as synchronic phenomenal unity. Torrengo (2017) is also
committed to strong dynamism. He too thinks that all experiences
possess a flow-like character, a character that is irreducible to
representational properties of any
 kind.[7]


### 1.4 Methodological Controversies



Philosophers interested in uncovering the temporal properties of
consciousness have often found inspiration in scientific findings.
Recent discussions have featured a wide range of perceptual illusions
uncovered by psychologists very prominently--in several
much-discussed works Daniel Dennett (1991, Dennett & Kinsbourne
1992) drew the attention of philosophers to a number of
experiments where (seemingly) what we perceive is affected by stimuli
which lie in the future. In his ground-breaking chapter on the
experience of time in *The Principles of Psychology* (1890)
William James spends much of his time relating relevant work carried
out by German psychologists such as Exner, Helmolz and Wundt in the
preceding decades. As a comparatively new science psychology was just
getting started in the nineteenth century, but back in 1689 we find
Locke appealing to proto-scientific data when discussing our
experience of duration in his *Essay*, where Locke points out
that objects cannot be seen if they move fast enough (e.g., cannon
balls), and that a glowing piece of coal appears as a circle when spun
quickly.



The question of the extent to which philosophical discussions of
temporal experience should be influenced by science is itself a source
of controversy. Lee recommends a hard-line science-oriented
methodological stance:



> 
> 
> My view is that the most powerful considerations in this area have to
> do with the ways in which temporal information is processed in the
> brain, so that ultimately what is at stake depends on empirical
> considerations of a quite general kind. [...] It is worth noting
> at the offset that because I adopt this "bottom-up"
> methodology, my approach contrasts quite strongly with certain other
> authors such as Dainton (2000) who argues for views in this area more
> on the basis of phenomenological than empirical considerations. (Lee
> 2014a: 2)
> 
> 
> 



In the introduction to his *Stream of Consciousness* Dainton
(2000) willingly concedes that in attempting to understand
experiential unity and continuity his own approach will be exclusively
phenomenological. He argues that his approach is justified because
there exist important experiential structures that are in fact
accessible to introspection, and we currently have no other way of
accessing these features. Neuroscience may one day be in a position to
assist but significant advances will need to be made--indeed
Dainton suggests in



> 
> 
> situations in which the phenomenological data conflict with accepted
> science may well provide valuable clues as to how the relevant science
> might be revised and improved. (2000: 23).
> 
> 
> 



Kon and Miller (2015) advocate a middle way between Dainton's
"top-down" phenomenological approach and Lee's
"bottom-up" approach rooted in neuroscience. They suggest
that advances in our understanding of temporal experience will require
us to successfully integrate armchair analysis and empirical
evidence:



> 
> 
> we foresee that empirical evidence may significantly modify classic
> models these models are still of use: they offer a starting point for
> empirical enquiry by placing key features of our experience into
> coherent models. Plus, they offer general frameworks in which
> particular empirical models may be slotted and that potentially have
> testable consequences. (2015: 215)
> 
> 
> 



If temporal illusions have played a significant role in recent debates
but the same cannot be said of the general neuroscientific theories of
consciousness--theories which purport to identify the neural
basis of consciousness and (more ambitiously) explain how and why
neural processes produce experiences in all its forms. It is far from
being the case that general theories of this sort do not exist, or are
even thin on the ground--see Wu (2018) for an introduction to
several. Why have philosophers interested in temporal experience paid
comparatively little attention to these theories? Kent and
Wittmann (2021) propose an answer: to a surprising extent the main
general theories of how consciousness relates to the brain make no
attempt to explain or accommodate *experienced*
*succession*, at most they can explain *experienced*
*simultaneity* as it features in the briefest of conscious
episodes. Northoff and Lamme (2020) review eight leading
neuroscientific theories of consciousness: global neuronal workspace
theory (GNWT), predictive coding theory (PCT), embodied theory (EB),
temporospatial theory of consciousness (TTC), integrated information
theory (IIT), recurrent processing theory (RPT), synchrony theory (ST)
and higher-order thought theory (HOT). The majority of these, Kent and
Wittmann argue, focus exclusively on processes in the sub-300 msec
range, the sorts of neural processes that are generally thought to
give rise to momentary experiences of simultaneity. These leading
theories have nothing to say about neural processes occurring over
longer intervals, from 300 msec to 3 seconds or more, that it is
plausible to suppose will be underlie experiences of change and
succession. Only RPT and Northoff's own TTC offer anything
different: these theories hold that experienced succession depends on
oscillatory neural process that extend over significant periods of
time.



If Kent and Wittmann are right it's obvious why general
neuroscientific theories have--thus far at least--had so
little impact on the philosophical debates. Whereas the latter offer
competing accounts of the experience of temporally extended phenomena
seemingly stretching over intervals of time, the neuroscientific
theories have largely confined themselves to a single experienced
moment. If neuroscience starts to move beyond its current very narrow
temporal focus its impact will very likely begin to increase.



These considerations do not mean that it is impossible for the
philosophical debates to impact on neuroscience. To focus on just one
example, the current incarnation of IIT is quite explicit regarding
the narrow temporal confines of consciousness:



> 
> 
> ... my experience flows at a particular speed--each
> experience encompassing a hundred milliseconds or so--but I am
> not having an experience that encompasses just a few milliseconds or
> hours. (Tononi & Koch 2015: 6)
> 
> 
> 



Since these brief episodes are discrete and non-overlapping our
consciousness is less continuous than commonly thought:



> 
> 
> Accordingly, the seemingly continuous "stream" of
> consciousness would actually be constituted by a discrete succession
> of "snapshots" in line with some psychophysical evidence.
> (2015: 16)
> 
> 
> 



In effect Tononi and Koch are committing IIT to a version of the
cinematic model outlined earlier. This model does have its proponents,
so this in itself is not problematic. What is more puzzling, as
Singhal, Mudumba and Srinivasan (2022) point out is that IIT
distinguishes itself from other neuroscientific approaches by taking
phenomenology very seriously indeed. Yet the cinematic model is widely
taken to be the most phenomenologically implausible of the leading
theories of temporal experience--most of its proponents agree
that our ordinary consciousness seems to be deeply continuous. IIT is
distinctive by virtue of the singular importance it grants to the
*unity* of consciousness, but it makes no attempt to
accommodate the fact (as many see it) that the unity of consciousness
extends through time as well as existing at a time. To render IIT
maximally phenomenologically plausible these same authors recommend
this addition to IIT's current axioms:



> 
> 
> experience always occurs to us as a temporal whole, i.e. experience
> always has an extension, is continuous and has an inherent direction
> that is asymmetric. (2022: 14)
> 
> 
> 



If future versions of IIT were to include an axiom along these lines
it would be an interesting example of phenomenology influencing the
development of a neuroscientific theory.


## 2. Some Historical Episodes


### 2.1 William James



In the Anglophone philosophical world over the past century or so
William James' "The Perception of Time", chapter 15
of his classic *The Principles of Psychology* (1890) has been
particularly influential. In the chapter James introduces readers to
relevant experimental work as well as more philosophical reflections.
It was thanks to James' discussion that "the specious
present" entered the vocabulary of both philosophers and
psychologists. James gives E.R. Clay credit both for the term and for
recognizing that the "sensible present" has duration; he
quotes him thus:



> 
> 
> The relation of experience to time has not been profoundly studied.
> Its objects are given as being of the present, but the part of time
> referred to by the datum is a very different thing from the
> conterminous of the past and the future which philosophy denotes by
> the name Present. The present to which the datum refers is really a
> part of the past--a recent past--delusively given as being a
> time that intervenes between the past and the future. Let it be named
> the specious present, and let the past, that is given as being the
> past, be known as the obvious past. All the notes of a bar of a song
> seem to the listener to be contained in the present. All the changes
> of place of a meteor seem to the beholder to be contained in the
> present. At the instant of the termination of such series, no part of
> the time measured by them seems to be a past. (James 1890:
>  609)[8]
> 
> 
> 



James goes on:



> 
> 
> the original paragon and prototype of all conceived times is the
> specious present, the short duration of which we are immediately and
> incessantly sensible. (1890: 631)
> 
> 
> 



In another formulation he enters into more detail, and says something
about what this short duration contains:



> 
> 
> The unit of composition of our perception of time is a duration, with
> a bow and a stern, as it were--a rearward--and a
> forward-looking end. It is only as parts of this duration-block that
> the relation of succession of one end to the other is perceived. We do
> not first feel one end and then feel the other after it, and from the
> perception of the succession infer an interval of time between, but we
> seem to feel the interval of time as a whole, with its two ends
> embedded in it. (1890: 609-10)
> 
> 
> 



In the same chapter of the *Principles* James also writes:



> 
> 
> Its *content* is in a constant flux, events dawning into its
> forward end as fast as they fade out of its rearward one ...
> Meanwhile, the specious present, the intuited duration, stands
> permanent, like the rainbow on the waterfall, with its own quality
> unchanged by the events that stream through it. (1890: 630)
> 
> 
> 



James clearly believed that there is an unvarying *structure*
or *mechanism* underlying our temporal awareness, as did
Husserl after him. If this is right, and if (as many believe)
consciousness is essentially temporal, then this structure (or
mechanism) is an essential component of consciousness itself, in all
its forms.



James is well-known for emphasizing the *continuity* of
experience



> 
> 
> Consciousness, then, does not appear to itself as chopped up into
> bits. Such words as "chain" or "train" do not
> describe it fitly ... It is nothing jointed, it flows. A
> "river" or a "stream" are the metaphors by
> which it is naturally described (1890: 239)
> 
> 
> 



and James' stream metaphor strikes many as
 apt.[9]


### 2.2 Locke, Hume and Reid



If the nineteenth century saw a surge in interest in
time-consciousness due to discoveries in a range of different
fields--see Canales (2009) for more of the story--an
interest in these questions dates back far earlier. Saint
Augustine's labours in Book XI of the *Confessions* led
him to espouse a position that is at least highly suggestive of a
version of the cinematic conception outlined in
 SS1.
 Augustine subscribed to the doctrine of *presentism* (as it
has latterly become known), i.e., he held that only what is present is
real:



> 
> 
> What now is clear and plain is, that neither things to come nor past
> are. Nor is it properly said, "there be three times, past
> present and to come:" yet perchance it might be properly said,
> "there be three times: a present of things past, a present of
> things present, and a present of things future". For these three
> do exist in some sort, in the soul, but otherwhere do I not see them;
> present of things past, memory; present of things present, sight;
> present of things future, expectation. (*Confessions*, bk XI,
> ch XX, sect 26)
> 
> 
> 



Since for Augustine it was also clear that the present must be
entirely without duration, and that our perception is restricted to
what is present--"that only can be seen, which is"
(bk XI, ch XVIII, sect 24)--we are led swiftly to the conclusion
that we can perceive or experience only what is contained in a
momentary present.



Since we evidently possess *concepts* of persistence,
succession and suchlike, one would expect philosophers who believe
that our basic concepts derive their content from the content of our
immediate experience--philosophers such as Locke and
Hume--would incline in the direction of
 realism.[10]
 And generally speaking, albeit with certain complications, this is
what we find. In the *Essay* (1689) Locke writes:



> 
> 
> It is evident to anyone who will but observe what passes in his own
> mind, that there is a train of ideas which constantly succeed one
> another in his understanding, as long as he is awake. Reflection on
> these appearances of several ideas one after another in our minds, is
> that which furnishes us with the idea of succession: and the distance
> between any parts of that succession, or between the appearance of any
> two ideas in our minds, is what we call duration. (Chapter XIV, 3)
> 
> 
> 



Like Locke, Hume believed that our conception of time is derived from
our experience of the succession of our perceptions. In Book 1, Part
II(SS3) of his *Treatise* (1739) Hume writes:



> 
> 
> ... time cannot make its appearance to the mind, either alone, or
> attended with a steady unchangeable object, but is always discovered
> by some *perceivable* succession of changeable objects.
> (*Treatise* bk 1, pt 2, SS3 [1888: 35])
> 
> 
> 
> ... Five notes played on a flute give us the impression and idea
> of time; though time be not a sixth impression, which presents itself
> to the hearing or any other of the senses. [the mind] only takes
> notice of the manner, in which the different sounds make the
> appearance ... ([1888: 36])
> 
> 
> 
> ... the indivisible moments of time must be filled with some real
> object or existence, whose succession forms the duration, and makes it
> conceivable by the mind. ([1888: 39])
> 
> 
> 



Although Hume agrees with Locke over the origin of our concept of
succession, what he says about duration sits uneasily with
Locke's contention that we arrive at the latter concept by
observing the distances between impressions. For Hume



> 
> 
> the idea of duration is always derived from a succession of changeable
> objects, and can never be conveyed to the mind by any thing steadfast
> and unchangeable. ([1888: 37])
> 
> 
> 



Since a period of (total) silence between the hearing of two sounds
would not itself contain any change or succession--at least of an
auditory kind--the concept of duration cannot be derived from
this period of silence.



For Hume the fundamental ingredients of our streams of consciousness
are momentary (durationless) experiences occupying "invisible
moments" of time. If we were conscious of nothing beyond these
durationless episodes is not obvious how we could experience
succession. But Hume also held that we apprehend the way
("manner") momentary perceptions are arranged or
organized, and to these "compound impressions" there are
corresponding "compound ideas". As Lorne Falkenstein
interprets Hume, compound ideas are themselves extended in time:



> 
> 
> [Hume] takes ideas to be objects in their own right, that represent
> something else by resembling it. ... An idea of time represents
> time by being itself extended in time. (Falkenstein 1997: 193)
> 
> 
> 



If ideas of succession are themselves temporally extended, was Hume an
early advocate of extensionalism? For Adrian Bardon the answer is
clear and in the affirmative: in the *Treatise*



> 
> 
> Hume articulates an extensionalist account of our perception of space
> and time--an almost entirely disregarded account that really
> ought to be the locus classicus for extensionalism. (2019:
>  468)[11]
> 
> 
> 



In his *Essays on the Intellectual Powers of Man* (1785,
henceforth EIP) Thomas Reid questioned some of Locke's claims.
For Locke succession is a more basic concept than duration--since
we arrive at the concept of duration by reflecting on the distances
between parts of successions--but Reid argues the reverse is the
case. For a succession to exist at all, its parts--either
particular impressions or the intervals between them--must
themselves already have duration: for if these parts were all entirely
lacking in duration, we would be dealing with a purely momentary
phenomenon, and hence something which could not contain any kind of
succession. Hence succession presupposes duration, and not vice-versa.
Moreover, Reid held that our direct awareness is incapable of spanning
even a brief temporal interval: "Consciousness, and every kind
of thought, is transient and momentary, and has no continued
existence" (EIP: III.6, p. 336). If our consciousness is
instantaneous and transient it is difficult to see how we could ever
be conscious of succession, and this is the stance Reid adopts:



> 
> 
> It may here be observed that, if we speak strictly and
> philosophically, no kind of succession can be an object either of the
> senses or of consciousness; because the operations of both are
> confined to the present point of time, and there can be no succession
> in a point of time; and on that account the motion of a body, which is
> a successive change of place, could not be observed by the senses
> alone without the aid of memory. (EIP: III.5, pp. 325-326)
> 
> 
> 



Since the claim that we are immediately aware only of what is present
can seem common sense of the plainest sort, it is not surprising to
find Reid endorsing it. Reid recognizes that it seems equally
commonsensical to say that we *see* bodies move--after
all, we often talk in such terms: e.g., "I saw her waving her
arm". In response he argues that such talk is perfectly
legitimate, provided it is construed in loose or popular sense, and
not taken strictly and
 literally.[12]
 See Levanon (2016a) for a more detailed analysis of Reid's
views--and his criticisms of Locke.


### 2.3 Kant and Bergson



In the course of his elaboration of transcendental idealism in the
*Critique of Pure Reason* (1787) Kant made a number of claims
that would influence subsequent debates on temporal experience. These
are not always easy to interpret--for useful introductions see
Dunlop (2017) and Bardon (2019). For present purpose this passage in
"The Synthesis of Reproduction in Imagination" from the
first *Critique* is particularly relevant:



> 
> 
> When I seek to draw a line in thought, or to think of the time from
> one noon to another, or even to represent to myself some particular
> number, obviously the various manifold representations that are
> involved must be apprehended by me in thought one after the other. But
> if I were always to drop out of thought the preceding representations
> (the first parts of the line, the antecedent parts of the time period,
> or the units in the order represented), and did not reproduce them
> while advancing to those which follow, a complete representation would
> never be obtained: none of the above-mentioned thoughts, not even the
> purest and most elementary representations of space and time, could
> arise. .... the reproductive synthesis of the imagination is to
> be counted as among the transcendental acts of the mind. We shall
> therefore entitle this faculty the transcendental faculty of
> imagination. (A102 [1980: 133])
> 
> 
> 



Anyone who holds that our sensory experience consists of nothing more
than a succession of momentary snapshots faces the problem of
explaining why we seem to be aware of duration and succession. Kant
held that our sensory experience does have this snapshot-like
character and solves the resulting problem by offering a richer
account of the momentary states. In the visual case, momentary
episodes of visual experiencing are accompanied by representations of
recently experienced visual contents. More generally, these
representations allow us to be aware that our presently occurring
experience is a part of an ongoing process.



More needs to be said, but Kant supplies at least the beginnings of
one plausible-looking account of how it might be possible for us to be
aware of change and succession in the way we seem to be, and it is an
approach that can be developed independently of Kant's
transcendental idealism--and its commitment to the unreality of
time. The "retentional" approach (recalling the
terminology of
 SS1.1)
 soon found advocates, and is comparatively commonplace by the end of
the nineteenth century.



If we move onward a century we encounter Henri Bergson, a philosopher
who placed a highly dynamic form of temporal experience right at the
centre of his philosophy. As Canales (2015) vividly demonstrates, at
the beginning of the twentieth century Bergson's writings on
time and consciousness had considerable influence on his
contemporaries, both within the philosophical world and beyond. In his
*Time and Free Will: An Essay on the Immediate Data of
Consciousness* (1889 [1910]) Bergson began his campaign against
the "spatializing" of time, and in this campaign the
concept of *duration* (or *duree*) plays a key
role. At least in his earlier writings, this concept applies to time
as it is featured in our immediate experience. For Bergson,
*duree* is a continuous dynamic experiential flow,
immeasurable and unquantifiable--the "ceaselessly seething
surd at the heart of things", in Barrett's words (Gale
1968: 373). As such it is radically unlike the static conception of
time as a manifold of mere locations to be found in the scientific
conception of the world, whether Newtonian or Einsteinian.



> 
> 
> Pure duration is the form which the succession of our conscious states
> assumes when our ego lets itself *live,*when it refrains from
> separating its present state from its former states ... We can
> thus conceive of succession without distinction, and think of it as a
> mutual penetration, an interconnexion and organization of elements,
> each one of which represents the whole, and cannot be distinguished or
> isolated from it except by abstract thought. (Bergson 1889 [1910:
> 100-101])
> 
> 
> 



Many of Bergson's characterizations of *duree* are
negative: he tells us a good deal about what it is not, but
comparatively little about what it actually is. While this can
sometimes be frustrating, there is a rationale for it: Bergson held
that any attempt to conceptualize the flux of consciousness could
succeed only at the cost of distorting the phenomena--a doctrine
which influenced William James in his later years--for more on
this see Dainton (2017a, 2022) and Dolev (2022).



In later works, such as *Matter and Memory* Bergson suggested
that primitive forms of *duree* can be found in all
material things, even the simplest particles and fields. If so,
temporal experience is ubiquitous, and there is a flowing dynamism at
the heart of literally everything. For more on Bergson's
conception of the nature of matter see Capek (1971) and Sinclair
(2019).



Bergson may have been influential during the first decades of the
twentieth century but not everyone was convinced of the fundamental
correctness of his metaphysical and phenomenological claims--even
in the Francophone philosophical world of the period. In his
*Intuition of the Instant* (1932) Gaston Bachelard launched a
radical assault on Bergson's account of the temporality of
consciousness and the temporality of the world. For Bergson the static
durationless instant of mathematics and physics is an abstraction to
which nothing in concrete reality corresponds--reality is
essentially extended and flowing. The position Bachelard defends is
diametrically opposed to Bergson's:



> 
> 
> Time alone has but one reality: the reality of the instant. Otherwise
> put, time is a reality confined to the instant and suspended between
> two voids. Although time will no doubt be reborn, it must first die.
> It cannot transport its being from one instant to another in order to
> forge a duration. (Bachelard 1932 [2013: 6])
> 
> 
> 
> ... time is the instant, and it is the present instant that bears
> the full weight of temporality. The past is as empty as the future.
> The future is as dead as the past. The instant holds no duration at
> its core; it does not thrust a force in one direction or another. It
> does not have two faces. It is whole and alone. (1932 [2013: 28])
> 
> 
> 



Bergson complained that conceiving of the continuity of experience in
mathematical terms reduces experience to a "dust of
instants". Bachelard responds thus:



> 
> 
> Time is noticed solely through instants; duration ... is felt
> solely through instants. Duration is a dust cloud of instants or,
> better yet, a group of points organized more or less coherently by a
> *phenomenon* of perspective. (1932 [2013: 19])
> 
> 
> 



While Bergson argued that the cinematic conception of the stream of
consciousness is fundamentally wrong, for Bachelard this conception is
essentially correct--and as we shall now see, he is not alone in
this.


## 3. Cinematic Approaches


### 3.1 Streams and Stills



When it comes to explaining the temporal structure of our
consciousness the account offered by the cinematic theorist is
appealingly straightforward. On a straightforward version of this
view, a typical stream of consciousness consists of a close-packed
continuum of momentary (or very brief) phases. Although the contents
of these phases are themselves momentary--they do not present
motion or change, they are akin to static snapshots. But their
occurrence in rapid succession succeeds in generating all the change,
succession and motion we find in our experience. Or so the cinematic
theorist maintains: on their view nothing more is required. The basic
features of the model are depicted in
 Figure 3.1.
 On the left we see a punctual beam of awareness, the smooth, steady
advance of which generates a sequence of momentary snapshot-like
contents (of a falling object, in this instance), only a small
selection of which is shown on the right.



![link to extended description below](streams-stills.svg)

Figure 3.1 The Cinematic Model. [An
 extended description of Figure 3.1
 is in the supplement.]




As we saw earlier, this approach can be traced back as far as St.
Augustine and was later advocated by Reid, and more recently by
Bachelard. Phillipe Chuard (2011, 2017, 2020) is a contemporary
defender of the view, calling it the "snapshot
theory":



> 
> 
> ... the snapshot theorist argues, the phenomenology we seem to
> introspect while enjoying successive experiential states not only
> *supervenes upon*, but *reduces* to, those features of
> successions just listed: the experiential properties of snapshots,
> their temporal arrangement, the gradual transitions in their
> successive contents, our memories of previous experiences, and
> inability to detect small gaps and jumps, all contribute to what
> it's like to enjoy the sort of phenomenology associated with
> putative temporal experiences. (Chuard 2017: 125)
> 
> 
> 



In
 SS1.2
 a distinction was drawn between realists and anti-realists, with
realists holding that change and succession can be directly perceived
and anti-realists maintaining that it cannot. Chuard denies that
change can be directly apprehended, putting him in the antirealist
camp. But he also accepts that we *seem* to directly experience
change--so realism appears to be true, even if it
isn't.



To be clear, the snapshot view isn't trying to explain how we
do, in fact, have temporal experience. We don't, the snapshot
theorist surmises. Rather, the view aims to explain what it is like to
go through successions of very short conscious experiential states, to
then point out how the phenomenology thus accounted for seems
indiscriminable from the phenomenology associated with the temporal
experience we allegedly enjoy. Thus, the snapshot view doesn't
reject the phenomenological appearances, quite the contrary. It aims
to explain them without liberally assuming that such experiences must
be taken entirely at face value, as revealing the metaphysical
structure of our streams of consciousness. (Chuard 2017:
 126)[13]



Critics of the cinematic theory are generally of the view that James
was correct when he drew a sharp distinction between a mere succession
of experiences and an experience of succession, and since the
cinematic theorist is providing us with no more than the former it
cannot deliver an adequate account of the latter. Dainton (2000:
SS5.5; 2008b: 57) invites us to imagine a group of five people
standing in line with their eyes closed, but directed at a nearby
tennis game. If each of these people opens their eyes momentarily
before closing them again we have a succession of five experiences,
each revealing the on-court action at a particular moment. It seems
clear that in this case there is nothing resembling an experience of
succession: all each person sees is a momentary still image, and these
momentary states are completely isolated from one another
experientially. There is, Dainton suggests, a huge difference between
this sequence of experiences and our own streams of consciousness, but
since the cinematic theory fragments consciousness in an analogous way
it is deeply implausible
 phenomenologically.[14]



As for how sequences of momentary static snapshots can give rise to
experiences with *seemingly* dynamic contents Reid and Chuard
both hold that memory plays an important role. In Reid's
words:



> 
> 
> It is by memory that we have an immediate knowledge of things past:
> The senses give us information of things only as they exist in the
> present moment; and this information, if it were not preserved by
> memory, would vanish instantly, and leave us as ignorant as if it had
> never been. (EIP: III.1, p. 303)
> 
> 
> 



But is memory enough? Phenomenologically there is an obvious
difference between perceptual experience and experiential memories:
the latter are far less detailed and far less vibrant than the former.
Given this, it is not obvious that combinations of instantaneous
perceptual experiences and memories could provide us with the sorts of
experiences of change we actually enjoy: successions of experiences,
yes; experiences of succession, no. For further discussion of appeals
to memory see Dainton (2000: SS5.4) and Phillips (2010:
SS5).



What of the cinematic analogy itself? It is well known that rapid
successions of static images *can* result in experiences of
motion. The images shown on a TV or cinema screen are static
snapshots, but evidently, they are perceived as dynamic: objects on a
cinema screen are seen to move as smoothly and continuously as their
real-life counterparts. This phenomenon--known as "illusory
motion" or "the phi phenomenon" was first explored
in the nineteenth century by Exner, and has been much-studied since
then (not surprisingly, since it underpins televisual industries). But
while it is real enough, the phi phenomenon is of little assistance to
the cinematic theorist. What the latter needs is an account of how
successions of *momentary conscious states*, each possessing
entirely static contents, can give rise to the experience of motion.
Static images are indeed being displayed on a cinema screen while we
view a movie, but not only are these onscreen stills not themselves
experiences, they do not register in our visual experience *as*
static images: what we actually seem to see onscreen are objects
*in motion*.



In the scientific literature the hypothesis that perceptual experience
comes packaged in discrete sub-second "frames" possessing
static contents has been defended on a number of occasions. White
(2018) undertakes a detailed survey of the relevant work in psychology
and neuroscience. White's verdict is that the discrete frames
hypothesis has not yet been decisively refuted, but it is seriously
problematic on a number of fronts.



The available evidence does not provide consistent support for any
specific duration for frames, and perceptual processes display a
flexibility that is not readily reconcilable with the frame
hypothesis. There are also



> 
> 
> problems concerning the definition of frames, the need for
> informational connections between frames, the means by which
> boundaries between frames are established. (White 2018: 98)
> 
> 
> 


### 3.2 Dynamic Snapshots



Cinematic theorists would be on stronger ground if they could supply a
plausible explanation as to *why* we believe we perceive motion
(and more generally, change) if in fact we do not. Le Poidevin (2007:
88-92) tentatively forwards a promising hypothesis. As Aristotle
noted, if you stare at a waterfall for a short period, and then turn
your gaze to the bank beside it, you will see part of the bank
(seemingly) start to move in an upwards direction. This phenomenon is
commonly called "the waterfall illusion" (or *motion
aftereffect*), and the illusory motion is of an intriguing sort:
although parts of the bank seem to flow upward, they do so without
seeming to change their location with respect to the rest of the
bank.



As for an explanation of what is going on in such cases, Le Poidevin
(following Richard Gregory) suggests that perhaps we can discern here
the workings of two distinct neural mechanisms. One



> 
> 
> registers what we might call "pure motion", i.e., gives
> rise to the impression of motion without any associated sense of
> change of position. (2007: 89)
> 
> 
> 



A second system, relying on short-term memory, tracks and compares the
alterations in location over time. This second system is not concerned
with telling us about presently occurring motions, rather it gives
rise to the sense that objects have changed their positions relative
to one another. Hence Le Poidevin's proposal: perhaps our
ordinary experience of motion does, after all, consist of nothing but
momentary static snapshots but these momentary experiences
*seem* dynamic thanks to the activation of the "pure
motion" mechanism in our visual system.



This is a more promising line for the cinematic theorist to take, and
it has recently been endorsed by Arstila (2018), and also been taken
up by Prosser, where pure motion plays an important role in his
dynamic snapshot theory:



> 
> 
> ... it is a "snapshot" theory because it accounts for
> the experience of motion without appeal to a specious present, but it
> is very different from the cinematic or "static snapshot"
> theory. I agree with those who hold that the latter theory cannot
> adequately account for the phenomenology of motion experience. (2017:
> 149, see also Prosser 2016: SS5.4)
> 
> 
> 



This supposedly dynamic version of the cinematic view may be more
promising than the static alternative, but it has also come under fire
from a number of directions. McKenna argues thus:



> 
> 
> For the experienced illusory object ... to appear static in
> space, but with motion-like properties, it must exhibit persistence
> over some length of time. temporality is inescapable; events continue
> to succeed one another over time, even if the content remains the
> same. (2021: SS6)
> 
> 
> 



Shardlow makes a similar complaint:



> 
> 
> Contrary to what Prosser and Arstila suggest, it simply does not
> follow that the experience of motion is not in and of itself something
> with a fundamentally temporally extended phenomenology, and that
> motion/change as it is experienced seems processive.... (2019:
> 745)
> 
> 
> 



It may well be a mistake to focus exclusively on the case of vision:
after all, in addition to being seen, change can be heard, smelt,
tasted, felt in bodily sensations, remembered, imagined and thought
about. Even if the existence of the envisaged twin-track neural
systems could be established in the visual case, critics point out
that as things currently stand there is no reason for thinking Arstila
is correct when he proposes that there are a range of different
encapsulated systems, one for each of the other forms of temporal
experience. On the contrary: if, as has seemed plausible to many,
*all* forms of consciousness possess a dynamic temporal
character then it is natural to conclude that temporality is closely
connected with the neural processes that are responsible for
consciousness itself:



> 
> 
> Why adopt the encapsulated mechanism approach when it is simpler, more
> explanatory, and truer to the phenomena to locate temporality as a
> feature of a general mechanism responsible for consciousness, whatever
> that may be? A feature of a general mechanism also has the benefit of
> accounting for why people never seem to go "timeless" the
> way people go "blind"--temporality is indispensable
> to consciousness because it is inextricably bound up with the
> processes responsible for it. (McKenna 2021: SS5)
> 
> 
> 



McKenna suggests that the future-oriented predictive processing
proposal from Hohwy, Paton, and Palmer (2015) fits the bill. An
alternative general neuro-scientific mechanism is proposed by Piper
(2019), who points to the merits of the re-entrant oscillatory
multiplexing (ROM) neurodynamical model. On the latter view the
temporal features of consciousness are the product of interlocking and
interdependent waves of neural activity that are extended through time
in a manner that is difficult to reconcile with the cinematic view in
any of its guises but eminently compatible with rival extensional
models. Just as



> 
> 
> music is a product of various auditory *resonances* (in rhythm,
> pitch and timbre, for example) amongst the parts of the active
> orchestra. Analogously the ROM model formalizes the idea that coherent
> mental representations and experience is the product of various
> resonances (i.e. multiplexing) between the phases, frequencies and
> amplitude parameters ... of reciprocally connected
> information-processing (i.e. reentrant) brain circuits. (Piper 2019:
> 9-10)
> 
> 
> 



In a similar general vein Northoff (2016) and Northoff and Huang
(2017) argue that the temporal features of consciousness are
inextricably bound up with continuous neural oscillations that are
extend through time in a continuous manner. These "slow cortical
pulses" are low frequency waves of neural activity that allow
the brain to unify stimuli that are temporally separated. This
position also runs counter to cinematic conceptions but gels neatly
with extensionalism.


## 4. Retentional Approaches


### 4.1 Motivations



Endorsing the Augustinian doctrine that consciousness is confined to
the present point of time does not oblige one to reject the claim that
change and succession feature prominently in immediate experience.
These theses are quite compatible with one another provided the
experience of change occurs *within* the confines of the
momentary present. Indeed, in the eyes of some--but not
all--this is a necessary precondition for contents to be
experienced together as parts of a unified whole. The obvious way of
developing an account along these lines is to hold that momentary
episodes of sensory consciousness are accompanied by a simultaneously
existing array of *representations* (or *retentions*) of
immediately preceding conscious states, and our awareness--at a
single moment of time--of this combination of ingredients
provides us with what we take to be a direct awareness of change and
succession. This "retentional" approach--recalling
the terminology of
 SS1.1--was
 comparatively commonplace by the end of the nineteenth century and
continues to attract supporters.



Many realists have no doubt found this approach appealing because it
offers a simple and intuitively satisfying explanation of how an
experience of succession differs from a mere succession of
experiences: in the former case, the contents forming the succession
are presented together, as an ensemble, to a single momentary
awareness. Brentano and Husserl both subscribed to the *Principle
of Simultaneous Awareness* (PSA) that we encountered in
 SS1.2:
 "If one is aware of a succession or duration, one is
necessarily aware of it at one moment". Indeed, it may well be
that some theorists, consciously or unconsciously, have found the
retentional approach appealing because of the way it (in effect)
*reduces* the problem of diachronic phenomenal unity to the
comparatively straightforward problem of synchronic unity.


### 4.2 Brentano and Husserl



Brentano recognized that reaching a clear understanding of how it is
possible for us to directly experience succession and persistence is a
central issue for phenomenology (or "descriptive
psychology" as he preferred to call it). He also recognized that
a mere succession of experiences does not, in and of itself, add up to
an experience of succession. Brentano's solution: when listening
(say) to an extended tone or melody, at each moment you are aware of a
momentary sound-phase, but you are also (and simultaneously) aware of
a series of representations (or retentions) of the immediately
preceding phases. The latter Brentano referred to as
*proteraesthesis*. Brentano's approach gives rise to
several questions. How can contents which are simultaneous,
objectively speaking, seem to be successive? What is the precise
nature of the representations occurring in proteraestheses?
Brentano's views on these matters underwent several
changes--see Chisholm (1981) and Kraus (1930 [1976]) for further
details.



The early years of the twentieth century see Husserl developing an
account of time-consciousness along retentional lines. Husserl
attended Brentano's lectures between 1884-6; inspired by
them, he decided to devote his energies to philosophy rather than
mathematics. In elaborating his own position, in lectures in
1904-6, Husserl begins with criticisms of what Brentano (and
Meinong) had to say on the topic, but the position he ends up with is
along the same general lines. Husserl may not have adopted the term
"specious present", but he did hold that we have a
seemingly direct awareness of change and persistence amongst the
objects and processes we perceive over short intervals. He also held,
plausibly, that as our streams of consciousness flow on, we have an
awareness of their so doing. As for how this is possible, he thought
it must involve past phases of consciousness somehow being
"retained in grasp" in later moments of consciousness.



At the heart of Husserl's account is a dynamic tri-partite view
of the composition of consciousness at any instant. The three
components are: *primal impressions*, *retentions* (or
"primary memories") and *protentions*. Primal
impressions are the live, actual experiences that occupy the momentary
now. No sooner does a primal impression occur than it slips seamlessly
into the past. But it does not vanish from consciousness altogether:
it survives in the form of a retention, which presents it *as*
past. For Husserl, retentions are a quite distinctive form of
consciousness, and differ significantly from ordinary memories. As for
protentions, these are the future-oriented counterparts of retentions.
In some cases--e.g., when we are perceiving or remembering a
familiar sequence of events--they can be quite detailed, but
often they consist of nothing more than an *openness* to the
future, an expectation that *something will come*.



![link to extended description below](husserl-time.svg)

Figure 4.1 Husserl's time diagram.
[An
 extended description of Figure 4.1
 is in the supplement.]




The basic mechanics of Husserl's theory are depicted in
 Figure 4.1,
 where the horizontal axis represents a continuous flow of primal
impressions, the vertical axes represent a selection of retentions
(and in the case of F) protentions which accompany the primal
impressions D, E and F. (Only a "selection" because in
reality, according to Husserl, a continuous stretch of consciousness
consists of a dense continuum of primal impressions, each of which is
accompanied by its "comet's tail" of retentions and
protentions.) As can be seen, individual primal impressions are
retained in later specious presents--increased
"pastness" is indicated by a greater number of asterisks.
What goes for momentary primal impressions also goes for intervals:
D-E is retained at F in the form of the retentional continuum
E\*-D\*\*.



The broad outlines of Husserl's position may be clear enough,
but the details pose more of a challenge. Husserl wrote voluminously
on time-consciousness throughout his career but never found a position
he was happy with for long--in his lectures from 1907-10 he
found fault with the position he elaborated in the 1904-6
lectures--and he never published a definitive statement of his
position. For useful introductions to Husserl's views see
Kortooms (2002) and Zahavi (2004, 2007, 2010).


### 4.3 Temporal Illusions and Neuroscience



In a series of papers Rick Grush has developed a version of
retentionalism in the form of the "trajectory estimation
model" (TEM) which draws on ideas and analyses from control
theory and signal processing--for further details, see Grush
(2005a, 2005b). So far as analogies with Husserl's doctrines are
concerned, a key point is that the internal models employed by these
systems are not confined to representing *instantaneous* states
of the relevant domain. What is modelled, rather, is
the *trajectory* of the domain over a short interval of time,
i.e., the entire succession of states that the system estimates that
domain is most likely to have been in during the relevant interval. It
is this trajectory which Grush takes to be the information-processing
analogue of Husserl's tri-partite specious presents.



Grush argues that the abilities of his systems to generate different
(and incompatible) representations of what is being perceived at a
given time is a positive boon, for it allows his theory to accommodate
a variety of temporal illusions. In so-called
"post-dictive" illusions what is experienced as seemingly
occurring at a time *t* is influenced by stimuli arriving later
than *t*. One such illusion is the *cutaneous rabbit*
described by Geldard & Sherrick (1972). The experiment involved
devices capable of delivering controlled brief (2 msec) pulses to the
skin being fitted along the arms of subjects. Surprisingly, when the
devices were clustered in just three tight configurations--and
the wrist, the elbow and in-between--and five pulses were
delivered to each location, rather than experiencing three tight
clusters of pulses (one at the wrist, one at the elbow and one
in-between) subjects report feeling a succession of *evenly
spaced* pulses starting at the wrist and terminating a the elbow.
There are several questions that can be asked about this, but perhaps
the most puzzling is: what is happening at the time of the
*second* pulse? How is the brain able to adopt the
"evenly spaced" interpretation *before* the second
flash even occurs?



Grush's TEM has no difficulty explaining what is going on in
such cases. In the case of the rabbit, the second pulse is initially
experienced as occurring at the wrist. But as the brain updates its
models in the light of subsequent sensory information and its own
expectations as to the likely scenario confronting it, it alters its
verdict and the second pulse is experienced as occurring further along
the arm, as part of an evenly spaced succession. When subjects are
subsequently queried as to what they experienced, it is the later
experiences which get reported--the earlier ones are not
remembered.



Proponents of competing approaches have defended different ways of
interpreting post-dictive illusions. Dainton (2008a: 381) argues that
cases of this sort pose no problem for extensionalists:



> 
> 
> might it not be that our visual systems take some time ... before
> producing experience in response to a given stimulus? And might they
> not use this time to work out a *single* *coherent*
> version of events before committing it to experience?
> 
> 
> 



Eagleman and Sejnowski (2000) proposed a "delayed
response" construal of the flash-lag illusion along these lines.
In response Grush (2016: 5.1.1
 [Other Internet Resources])
 argues that since this additional delay will have to be incurred in
*all* our perceptual systems *all* the time, positing it
is by no means cost-free. Arstila (2016a) argues that Grush and
Dainton's explanations of post-dictive visual illusions are both
problematic, and proposes an
 alternative.[15]



Geoff Lee (2014a, 2014b) defends what is arguably a retentional model
of temporal experience, albeit one possessing some distinctive
features. Lee holds that specious presents are housed in experiential
states that have a very brief temporal extension--Lee thinks
these states are identical with neural states and processes, and the
latter always have a non-zero temporal magnitude. Although these
experiences possess some temporal extension they do not have any
*experiences* as proper parts, and so Lee aptly calls them
"atomic experiences". Extensionalists view specious
presents as temporally extended experiences which *do* possess
other experiences as proper parts, and for Lee this is the defining
feature of extensionalism. None of the seemingly-extended contents of
Lee's atomic experiences seem to be past- or
memory-like--they are all fully perceptual in character--and
so different from Husserlian
 retentions.[16]



One of Lee's main arguments for preferring a version of the
retentional (atomic) model is his "Trace-Integration
Argument", which has its roots in his preferred science-oriented
methodology. Lee points out a basic and widespread assumption in
recent cognitive psychology: information concerning what has been
recently perceived must be simultaneously present in subsequent
representations if it is to play any role in cognition (Lee 2014a:
15). It does seem plausible to suppose that our brains engage in
coding of the sort Lee describes. What is more controversial is
whether this is the *only* kind of processing that our brains
engage in when generating temporal experience. For a critical
assessments of Lee's argument Viera (2019), and for very
different kind of neural models which rely on temporally extended
neural processes see Northoff (2016), Northoff and Huang (2017), and
Piper (2019).


### 4.4 Retentions and Representationalism



The retentional model faces a number of challenges. For the doctrine
to be plausible we must be able to make clear sense of the idea that
experienced duration can be contained in episodes of experiencing that
are themselves without discernible duration, and retentionalists also
need to be able to provide a plausible account of how retentions can
do the job required of them. For a number of recent
theorists--e.g., Grush, Kiverstein, Lee and Tye--a currently
popular theory of the nature of perceptual experience helps
retentionalism solve these and other problems.



In the philosophy of perception *representationalism* (or
*intentionalism*) is the doctrine that the phenomenal
properties we encounter in perception are determined by, or supervene
upon, "representational" contents. Needless to say
representations come in very different forms, and the variety deployed
by recent representationalists is of a distinctive kind. As Siegel
usefully notes:



> 
> 
> when one speaks of the contents of a newspaper, one is talking about
> what information the newspaper stories convey. Many contemporary uses
> of "the contents of perception" take such contents to be
> analogous to the contents of a newspaper story. (2005 [2021:
> SS2])
> 
> 
> 



The stories we encounter in newspapers often make claims about the
world, and can be assessed for their truth or accuracy, and one way of
specifying the content of a story is by specifying what would have to
be the case if the story is true. Representationalists maintain that
the contents carried by perceptual experiences are similar: we can
specify their content by specifying the conditions under which they
are true (or reliable). Importantly, on this view perceptual
experiences can have representational contents even if the story they
are telling is false: we do, after all, misperceive things from time
to time--a balloon which looks red might turn out to be
orange.



Representationalists hold that, quite generally, the properties of a
representational *vehicle* (that which is doing the
representing) and the *content* of that representation (what is
represented) need to be sharply distinguished. The word
"red" can represent the colour *red* without itself
being red. A copy of a newspaper is very different from the stories it
tells. In the case of temporal experience anyone who finds this theory
of perception appealing can adopt a quite straightforward position on
the nature of retentions: the latter provide us with a direct
awareness of the recent past because they are perceptual experiences
possessing meaningful contents that represent the recent past. The
problem of understanding how the experienced duration and succession
can exist in experiences that are durationless (or almost so) now has
a straightforward solution. As we have just seen, representational
vehicles and their contents typically do have very different
properties, and this is a case in point. In the representationalist
framework it would be a mistake to expect the temporal properties of
an experience, a vehicle, to match those of its content.



Hoerl (2013a) argues that some of Husserl's otherwise puzzling
pronouncements become a good deal less puzzling if we suppose that he
changed his stance from something akin to a sense-datum theorist (in
his early days) to something akin to contemporary representationalism
(in his later days). Husserl tells us that "Memory--and
this is equally true of retention--is not image-consciousness, it
is something totally different" (Husserl TPZ [1991: 36]). He
also says that as a primal impression is transformed into a
retention



> 
> 
> there is a radical alteration, an alteration that can never be
> described in the way in which we describe the changes in sensations
> that lead again to sensations. (Husserl TPZ [1991: 336])
> 
> 
> 



We can see how Husserl might have thought this true is he had (in
effect) adopted
 representationalism.[17]



There is a further doctrine defended by many representationalists that
is also relevant to our current concerns: an insistence on the
"transparency" of experience. By this they typically mean
(in part at least) that in ordinary perceptual experience, we have no
awareness whatsoever of our experiences themselves, we are simply
aware of the (worldly) objects and properties that are presented in or
by our experiences. If our experiences are invisible, there is no need
to introduce properties *of* experience--phenomenal
properties, qualia, sense-data and such--in order to explain the
content and character of our ordinary perceptual consciousness.
Extending this approach to the particular case of temporal
consciousness, Michael Tye argues as follows. First of all, if we
assume the transparency thesis is true, the traditional assumption
that it is *experiences* that are related by succession or
simultaneity is misguided:



> 
> 
> Consider again the case in which I have an experience of a red flash
> followed by a green flash. Here I experience two colored
> *flashes* as occurring one after the other. I do not experience
> my *experience* of a red flash as succeeding my
> *experience* of a green one any more than I experience my
> experience of a red flash as red. (2003: 96)
> 
> 
> 



Accordingly, Tye holds that anyone seeking to account for our ability
to directly apprehend change by appealing to a unifying relationship
between experiences is also misguided: there simply aren't the
token experiences there to *be*unified; a given period or
stretch of consciousness is not composed of successive perceptions or
experiences (2003: 102). By way of an alternative he offers a *one
experience view* of streams of consciousness:



> 
> 
> The simplest hypothesis compatible with what is revealed by
> introspection is that, for each period of consciousness, there is only
> a single experience--an experience that represents everything
> experienced within the period of consciousness as a whole. (2003:
> 97)
> 
> 
> 



For a recent defence of Tye's general approach to transparency
in the case of temporal experience see Heeney (2021). As Bayne notes,
Tye's one experience proposal does not sit easily with some of
his other views. Tye holds that experiences are representational
states that have the ability to directly feed into our cognitive
systems. Bayne asks:



> 
> 
> Is it really plausible to suppose that the contents of an entire
> stream of consciousness--that is, the period of consciousness
> between one state of unconsciousness and the next--are poised for
> direct input in to the reasoning system? ... That seems
> *extremely* unlikely. (Bayne 2005: 498)
> 
> 
> 



Soteriou (2010: 230) is also puzzled by this aspect of Tye's
position.



For discussion of some further issues relating to retentional specious
presents see the supplementary document
 The Specious Present: Further Issues.


## 5. Extensional Approaches


### 5.1 Origins: A Dogma Rejected



Stern observes at the start of his "Mental Presence-Time"
(1897 [2005]) that much recent work in psychology makes an assumption
about the kind of unities that can exist within experience: only
contents that are *instantaneous* and *simultaneous* can
be apprehended together. Needless to say, this assumption amounts to a
commitment to PSA--see
 SS1.2.
 Stern proposes that we reject this constraint:



> 
> 
> That only those contents can belong to a whole of consciousness that
> exist together and are simultaneously present at any given time
> ... is a dogma, which, in a more or less veiled form, determines
> numerous psychological reflections. I consider this dogma, at least in
> this generalized form, to be false. I believe that there are instances
> when an apprehension first comes into being on the basis of temporally
> extended content of consciousness, in such a manner that every part of
> this content exists in an insoluble connection with every other part.
> (Stern, 1897 [2005: 313])
> 
> 
> 



Rejecting PSA brings a number of advantages. Experienced contents
which appear to be successive can really be successive, rather than
existing simultaneously (as with retentional models), similarly
episodes of consciousness which seem to persist through intervals of
ordinary objective time can really do so. Abandoning the dogma means
that temporal consciousness need no longer be systematically
misleading as to its own nature. Stern was well aware why his
contemporaries maintained that it was necessary to distinguish a
succession of experiences from an experience of succession. A sequence
of musical notes will only be experienced as a succession if they are
experienced together, with each being experienced as following on from
its predecessor. Stern was simply suggesting that these unified
experiential episodes are themselves extended over temporal intervals
rather than momentary.



> 
> 
> I therefore put forth the following principle: mental events that play
> themselves out within a stretch of time can under circumstances form a
> unified and complex act of consciousness regardless of the
> non-simultaneity of individual parts. That stretch of time over which
> a mental act can be extended I call its presence-time. (Stern 1897
> [2005: 315])
> 
> 
> 



Wundt held that complexes of sensory contents could only be
apprehended directly if they exist in a conscious whole
simultaneously. Stern rejects this: "As a whole, yes; as
simultaneous, no" (1897 [2005: 319]). What of the notion
"the present" if we follow Stern and embrace an
extensional model of temporal experience? Stern suggests we
needn't reject the idea that experiences can be present. All we
need do is define the present "as the totality of temporal and
spatial relations that can become the object of a direct
perception" (1897 [2005: 325]). Since we directly perceive
events spanning brief intervals, the present thus construed is a
positive and finite stretch of time.



How do individual presence-times combine to form streams of
consciousness? In ordinary life we are, after all, continually
conscious for hours at a stretch, whereas individual presence-times
are very short. Stern does not address this question in his article so
he can offer little assistance--see Dainton (2017b) for a fuller
account of Stern's views --however it was not long before a
promising proposal emerged. In 1915 Bertrand Russell published his
"On the Experience of Time" in *The Monist*, where
the stream-composition question is addressed. Russell begins by
introducing some key terms and theses. A *sensation* involves a
subject standing in the acquaintance relation with an object or
sense-datum. Russell makes it clear that he believes change can be
directly experienced, telling us:



> 
> 
> *Succession* is a relation which may hold between two parts of
> one sensation, for instance between two parts of a swift movement
> which is the object of one sensation; it may then, and perhaps also
> when one or both objects are objects of immediate memory, be
> immediately experienced, and extended by inference to cases where one
> or both of the terms are not present. (1915: 213)
> 
> 
> 



How do specious presents combine to form entire streams of
consciousness? Here Russell usefully goes beyond Stern and proposes
that neighbouring specious presents in the same stream of
consciousness are related by overlap or part-sharing. Let's
suppose A, B, C are brief sounds of the same duration that are
experienced as a succession in the same continuous stream of
consciousness; let's also suppose that the lengths of these
sounds are such that only two of them can be experienced together.
Russell suggests that the resulting temporally extended experience
will include two specious presents [A-followed-by-B] and
[B-followed-by-C], and since the experiencing of the B-sound is
numerically identical with the experiencing of the B-sound in the
later specious present the B is heard just once, not twice. The
resulting stream of auditory consciousness consists of a continuous
succession of sounds, each heard as following on from its predecessor,
where only two sounds are experienced together as directly
successive.



Russell goes on to offer a further important observation:



> 
> 
> If A, B and C succeed each other rapidly, A and B may be parts of one
> sensation, and likewise B and C, while A and C are not parts of one
> sensation. But A is remembered when C is present in sensation. In such
> a case, A and B belong to the same present, and likewise B and C, but
> not A and C; thus the relation "belong to the same
> present" is not transitive. (Russell 1915: 233)
> 
> 
> 



As Russell clearly appreciates, if the relation of "belonging to
the same present" *were* transitive, then A would
necessarily belong to the same (specious) present as C, and more
generally, all the partially overlapping phases of a stream of
consciousness would have the character of a single unified specious
present--and so you would now be directly experiencing what you
saw and heard when you first awoke this morning. Since this is
manifestly not the case, the "belonging to the same
present" relation is clearly not transitive.


### 5.2 More Recent Defences and Discussions


#### 5.2.1 Awareness, Simplicity and Overlap



John Foster has defended an overlap-version of the extensional view on
a number of occasions. Foster has no doubt that temporally extended
phenomena are an important feature of our ordinary experience,
observing that



> 
> 
> duration and change through time seem to be presented to us with the
> same phenomenal immediacy as homogeneity and variation of colour
> through space. (Foster 1982: 255)
> 
> 
> 



Foster begins his discussion by assuming an awareness-content model of
consciousness. Let's suppose a musical scale is being sung, and
the duration of the notes is such that a listening subject is aware of
three notes in succession. As the scale unfolds the subject will have
a succession of auditory experiences


* E1 = [*do-re-mi*],
* E2 = [*re-mi-so*],
* E3 = [*mi-so-fa*]



and so on. This sequence of experiences has a puzzling feature: it
looks as though the notes are being experienced more than once, with
*re* featuring in E1and E2, *mi* in E1, E2 and E3, and
*so* in E2 and E3. Experiences like this are not logically
impossible, Foster suggests, but our ordinary experience of listening
to a series of notes obviously doesn't include repetitions of
this sort.



Foster proposes a solution:



> 
> 
> a presentation of a temporal pattern is itself temporally extended,
> and it overlaps its predecessor and successor in, so to speak,
> presentational substance to the extent that its pattern overlaps
> theirs in phenomenal content. It is this double overlap which provides
> the key to the sensible continuity of sense experience and unifies
> presentations into a stream of awareness. (Foster 1979: 176)
> 
> 
> 



Each of the two horizontal brackets in
 Figure 5.1
 represents an act of awareness that is temporally extended and
unified; each of these extended acts produces a specious present, the
first consisting of the experiencing of *do-re* and the second
*re-mi*. Unrealistic repetitions are avoided by virtue of the
fact that the extended acts overlap by sharing a common part.



![link to extended description below](double-overlap.svg)

Figure 5.1 Foster's double overlap
theory featuring temporally extended awareness and contents. [An
 extended description of Figure 5.1
 is in the supplement.]




In his *Stream of Consciousness* (2000, second edition 2006)
Barry Dainton sets himself the goal of providing a phenomenological
account of the sort of unity and continuity we find in our ordinary
streams of consciousness. Dainton does not take any stand on the
relationship between the experiential and the physical, other than to
assume that consciousness is "an irreducible ingredient of
reality in its own right" (2000 [2006: xiv]). He also adopts an
indirect realist or "projectivist" view of perceptual
experience.



Dainton's initial focus is on the synchronic (at-a-time) unity
of consciousness. He argues that the *togetherness* of the
diverse experiences we are having at any one time is itself a feature
our experience, and after considering attempts to explain
co-consciousness in other terms Dainton concludes that it should be
regarded as a primitive relationship. Among the rejected accounts of
phenomenal unity is the thesis that experiential objects and contents
are unified by virtue of falling under a single act of awareness. The
idea that consciousness has an awareness-content structure--as
assumed by Foster--is an appealing one in several respects, but
on closer examination all forms of this "A-thesis" turn
out to be seriously flawed, or so Dainton argues. By way of an
alternative Dainton adopts a one-level view of the structure of
consciousness he calls the "simple conception":



> 
> 
> The A-theorist tried to keep awareness distinct from content, but
> since this turned out to be a mistake we must accept that awareness
> and content are not distinct ingredients within experience. It follows
> that consciousness is inseparable from phenomenal contents: when a
> given phenomenal item comes into being it comes into being as a
> conscious experience ... contents are themselves intrinsically
> conscious, and hence--in a manner of speaking--they are
> self-revealing or self-intimating. (Dainton 2000: 57)
> 
> 
> 



In the chapters of *Stream of Consciousness* devoted to
temporal experience Dainton argues that a number of existing
approaches face serious problems. These include memory theories in
various guises, pulse-theories, Broad's extended content model
and Husserl's version of retentionalism. Dainton concludes that
the "overlap" form of the extensional theory defended by
Russell and Foster has significant advantages over the alternatives,
and is worthy of further development. Amongst its other virtues it
offers a plausible explanation of the way consciousness can be
experienced as deeply continuous for hours at a stretch, something
rival approaches fail to provide.



For Dainton the earlier and later contents of an individual specious
present form a single unified experience by virtue of being
experienced together. Dainton argues experiences can be unified over
time in the same primitive way as experiences at a time, and so the
earlier and later contents within a single specious present can be
co-conscious, but diachronically rather than synchronically. There are
however, differences between the synchronic and diachronic forms of
co-consciousness. It is natural to think that synchronic phenomenal
unity is transitive, but as Russell and Foster noted, in the
diachronic case failures of transitivity are ubiquitous, and can occur
whenever two specious presents partially overlap. Dainton (2000 [2006:
chapters 8 and 9]) argues that co-consciousness in its synchronic and
diachronic forms connects experiences so profoundly that a form of
holism ensues, and since specious presents consist of experiential
parts connected by co-consciousness this form of holism extends to
them.



Dainton's account of individual specious presents has one
further ingredient. Dainton takes consciousness to be dynamic in a
strong way: he holds that our experiences typically exhibit a
"discernible *phenomenal flow* ... a sense that the
same kind of phenomenal quality is being continuously renewed"
(2004a: 15). It is difficult to see how this feature of our experience
could be explained by the co-consciousness relationship alone, since
the latter is a symmetrical relationship: if *do* is
co-conscious with *re* then *re* will be co-conscious
with *do*. Given this symmetry, how is it that we
*do-flowing-into-re*? It is at this point that Dainton
introduces an additional ingredient: phenomenal contents



> 
> 
> which are symmetrically joined by co-consciousness themselves possess
> an inherent directional dynamism. The C-tone is not a static auditory
> quality, but a flowing quality, likewise for D and E. This
> *immanent flow* is an essential ingredient of any auditory
> content, just as essential as timbre, pitch or volume. (2004a: 23)
> 
> 
> 



In
 Figure 5.2
 this dynamic flow is represented by horizontal arrows, and the upper
and lower brackets represent the span of diachronic
co-consciousness.



![link to extended description below](simple-overlap.svg)

Figure 5.2 Dainton's Simple Overlap
Model. [An
 extended description of Figure 5.1
 is in the supplement.]




In "Sensing Change" (2008a) Dainton introduces the
"extensional model" as the doctrine that individual
specious presents consist of "temporally extended episodes of
experience that are apprehended as wholes". Dainton also
responds to Grush's claim that the extensional model is
incapable of accommodating temporal illusions such as the
phi-phenomenon in a plausible manner: one way of making sense of the
illusions is to suppose that our brains take some time before deciding
on an interpretation of incoming stimuli. In response Grush (2017)
offers several criticisms of this "delayed
extensionalism", and argues that the envisaged processing delay
would be more problematic than Dainton realizes. Arstila (2016a)
argues that the approaches defended by Grush and Dainton are both
problematic, and offers his own alternative account of apparent
motion.



On a different theme, Dainton (2014) focuses on various issues related
to the temporal structure of consciousness on the smallest of scales,
and he defends the view that our streams of consciousness are
"essentially extended continua" whose smallest parts have
some finite temporal extension. By virtue of not being composed of
strictly momentary parts a challenge to extensionalism by Pelczar
(2010a, 2010b) can be met, or so Dainton proposes.



Some of Dainton's criticisms of alternative approaches have
themselves come under critical fire. Gallagher (2003) argues that many
of Dainton's criticisms of Husserl are ineffective if Husserl is
construed in the right sort of way--Dainton (2003) responds. Dan
Zahavi finds that Dainton's analysis of the structure of streams
of consciousness has many virtues (2007: 470) but is also problematic
in several respects. Zahavi is also inclined to view experiences as
intrinsically conscious, but argues that Dainton's simple
conception of consciousness goes too far and in the end is too
simplistic. He is unimpressed by Dainton's claim that Husserl
simply stipulates that retentions have the mysterious features they
need in order to make his theory work, pointing out that Dainton
himself takes co-consciousness to be a primitive feature, one that
cannot be analysed or reduced to anything else "and if he can
employ that kind of argument, I fail to see why Husserl can't as
well" (Zahavi 2007: 468).



Prosser finds the notion of co-consciousness that Dainton takes to be
primitive phenomenological feature "quite mysterious"
(2016: 147) and so unhelpful:



> 
> 
> I can only say that in my own case I am not at all certain what it
> should be like for two of my experiences to be co-conscious and yet
> not occur at the same time without this simply being a case of the
> earlier experience being retained in a short-term memory. (2016:
> 147)
> 
> 
> 



Coming from a similar direction Chuard (2017: 127-8) suggests
that since snapshot theorists can accommodate the seemingly flow-like
character of experience there is no need for the theoretical apparatus
Dainton's approach requires.



Rashbrook (2013c) finds Dainton's claim that synchronic and
diachronic co-consciousness are different forms of the same kind of
basic relation problematic for a different reason. If Dainton is right
in claiming that co-consciousness is primitive then "the only
features of the relation that we can describe are its logical
properties" (2013c: 479), and these differ. Doesn't the
fact that synchronic co-consciousness is transitive and diachronic
co-consciousness non-transitive mean we are dealing with two relations
here, rather than one? There is a tension in Dainton's
position--as Bayne (2001: 85) also notes--but the situation
may not be as clear-cut as Rashbrook suggests. Co-consciousness may be
a basic relation but this does not mean that our knowledge of its
nature is confined to its logical properties. We are also--or so
Dainton claims--acquainted with its phenomenological character:
co-consciousness is simply a label for experienced togetherness, a
mode of unity which can be found binding simultaneous and also
successive contents in our streams of
 consciousness.[18]


#### 5.2.2 Temporal Structures and Transparency



In a number of provocative contributions Ian Phillips has argued that
much of the temporal experience debate has rested on confusions and
erroneous assumptions, which leads Phillips to call for a fresh start.
The main target of Phillips (2010) is the Principle of Simultaneous
Awareness (PSA), the doctrine that "if one experiences
succession or temporal structure at all, then one experiences it at a
moment" (2010: 177). Phillips suggests that this doctrine
underlies both the various memory theories found in the literature,
and specious present theories along the lines of Broad's (see
 SS6.1
 below). Phillips argues that PSA is false. If it were true then it
would be possible for the structure of our experience and the temporal
structure of the objects and events presented to us in our experience
to differ. But Phillips argues that this is in fact impossible.



Phillips' argument for this controversial claim rests on two key
claims. One is "Seems implies Is", experience cannot be
systematically misleading as to its own nature, and hence



> 
> 
> we cannot make sense of the idea that experience seems to one's
> rational introspective reflection to possess a certain temporal
> ordering, when it is not in fact so ordered. (2010: 183)
> 
> 
> 



The other key claim is that the temporal aspects of our experience are
"transparent" in a distinctive way:



> 
> 
> one's only way of making rational judgments about the temporal
> structure of experience itself, at least through reflection on
> one's experience alone, is by taking the temporal structure of
> the experience to map the temporal structure of the world as it is
> experienced as being. (2010: 184)
> 
> 
> 



If experience is transparent in this manner then we will judge that an
experience of a succession of notes will itself unfold over time in
just the way the notes seem to. If the "Seems implies Is"
principle is also correct then it is impossible for the temporal
properties of experience and its objects to systematically diverge in
the way PSA predicts.



In "The Temporal Structure of Experience" (2014c) Phillips
sets out to defend what he calls the "naive view" of
the manner in which the temporal structure of experience and the
temporal structure of the objects of experience are related.



> 
> 
> ... when all goes well, your stream of consciousness inherits the
> temporal structure of the events that are its contents. You
> "take in" the temporal structure of the events you witness
> in witnessing them. As a result, the temporal structure of experience
> matches the temporal structure of its objects. In cases of illusion,
> it is as if this is so. Thus, in every case, the temporal structure of
> experience matches the apparent temporal structure of the objects of
> experience. (Phillips 2014c: SS7.1)
> 
> 
> 



Phillips suggests naivete applies for temporal properties
such as simultaneity, successiveness, relative duration and temporal
order. Phillips goes on to address an objection. The claim that
experience is transparent is also commonly made by proponents of the
representationalist view of perception. Representationalists such as
Michael Tye maintain that perceptual experience is *entirely*
diaphanous, and hence that we have no introspective access to it, only
to the objects in the world that it reveals. If this conception of
transparency is correct, Phillips' claim that we have
introspective access to the temporal properties of our experience must
be wrong. In response Phillips points out when it comes to experience,
time is special. It may well be correct to reject the idea that an
experience of redness or squareness is itself red or square. But



> 
> 
> our experiential encounter with time is quite unlike color or shape,
> since our experience is not just of time, but also manifestly in time.
> (2014c: 144)
> 
> 
> 



For critical assessments of these views see Lee (2014a), Frischhut
(2015) and Viera (2019).



Phillips also makes a claim about what the extensional theory of
temporal experience really amounts to. Following Soteriou's lead
here, for Phillips the key and defining feature of extensionalism is
*not* simply a claim that an experience of change or succession
takes place over an extended period. It is that when it comes to
experience "it is significant stretches, not instants, that are
explanatorily and metaphysically fundamental" (2014c:149).



A number of theorists have argued that Phillips' inheritance
thesis--that for any temporal property apparently presented in
experience our experience itself possesses that temporal
property--is undermined by one or other temporal illusions.
Phillips disagrees, and in a series of papers devoted to different
illusions he finds ways of reconciling his naivete with
the allegedly problematic experimental findings. Several of the latter
centre on postdiction, the well-established phenomenon when what we
experience as occurring at a time *t* is influenced by sensory
stimuli occurring later than *t*. Phillips argues (2014c:
SS7.7-7.8) that provided we recognize that episodes of
experience extending over several hundred milliseconds are
metaphysically basic postdiction ceases to be deeply puzzling, for
there is no reason to assume happenings later than *t* are
irrelevant to what we experience at *t*. In Phillips (2014a)
the focus is on whether the so-called "motion-silencing"
illusion poses a threat to naivete, as some have argued
(for example, Suchow & Alvarez 2011; Watzl 2013). The illusion
features a ring of coloured dots which are seen to cease to changing
colour when they start rotating. Phillips argues that rather it is
best construed as a instance of change-blindness, rather than as a
failure of inheritance. In "Perceiving and the Passage of
Time" (2013) Phillips deals with the challenges posed by the
passage of time apparently speeding up reported by the survivors of
life-threatening dangers, along with other duration distortions
including the "odd-ball effect". Phillips (2014b) provides
a useful overview of his own work on temporal illusions.



Matthew Soteriou's stance on a number of issues runs parallel to
Phillips'. Soteriou also thinks that our perceptual experiences
are in certain important respects transparent. In ordinary perceiving
we seem to be directly aware not only of external worldly objects but
also of events which are extended through time, and we do not seem to
be aware of mental items such as sense-data. But he also thinks that
in ordinary perception we have an awareness of temporal aspects of our
experiences.



> 
> 
> Introspectively, it doesn't seem to one as though one can mark
> out the temporal location of one's perceptual experience as
> distinct from the temporal location of whatever it is that one seems
> to be perceptually aware of. Furthermore, it seems to one as though
> the temporal location of one's experience depends on, and is
> determined by, the temporal location of whatever it is that
> one's experience is an experience of. (Soteriou 2013: 89f.)
> 
> 
> 



If Soteriou is right, introspection can reveal the temporal properties
of not only the events we perceive, but also of the perceptual
experiences that are revealing these events, and the events and
experiences seem to have the same duration. Introspection can thus
provide evidence that our temporal experiences are themselves
temporally extended, given that we directly experience change and
succession--in line with extensionalism. See Hoerl (2018) for
some further discussion.



Among writers on temporal experience Soteriou is distinctive in the
emphasis he places on *ontological* issues, with different
types of mental states--when their nature is properly
understood--having quite different relationships with time. As
Soteriou makes clear, his own thinking on these questions has been
strongly influenced by Brian O'Shaughnessy. The latter
introduces his own position in *Consciousness and the World*
thus:



> 
> 
> Yet even when experience is not changing in type or content, it still
> changes in another respect: it is constantly *renewed*, a new
> sector of itself is there and then *taking place*. ... In
> short, the domain of experience is essentially a domain of
> occurrences, or processes and events. (O'Shaughnessy 2000:
> 42-43)
> 
> 
> 



In developing his own position Soteriou draws a distinction between
mental states and occurrent mental processes, with a distinguishing
feature of the latter being the way they *unfold* over time
whereas states don't. For Soteriou (2007: 551-55) the
basic units of temporal experience are temporally extended rather than
momentary:



> 
> 
> The answer we give to the question of what state a subject is in at a
> time is determined by the answer we give to the question of what state
> the subject is in during an interval of time that includes that
> instant.... (2007: 554)
> 
> 
> 



Soteriou defends a version of direct realism (or relationalism) in
which perceptual states are occurrent processes which are accompanied
by representational states which exist in virtue of perceptual
processes, and which wouldn't otherwise exist. Soteriou
argues--here following in Geach's footsteps--that
thought-like mental representations do not unfold over time in the way
perceptual forms of consciousness do, a fact which seriously
undermines the representationalist theories of perception in several
of its guises. For more on these themes see Soteriou (2007, 2010,
2013, 2018).



Oliver Rashbrook has put Soteriou's process-state distinction to
useful work, showing that it can help dispel confusions surrounding
the idea that consciousness is continuous (Rashbrook 2013b) and also
help meet Pelczar's challenge to extensional approaches
(Rashbrook 2013a). In a more critical vein see Rodriguez (2016)
and Steward (2018).


#### 5.2.3 Tense, Perception and Unity



In his "Time and Tense in Perceptual Experience" (2009)
Christof Hoerl also defends a form of extensionalism, albeit under the
guise of "molecularism". For Hoerl this approach can only
hope to be viable if it is formulated in tenseless rather than tensed
terms. Although specious present theorists have often assumed that
temporal experience is best characterized in tensed terms such as
"past", "present" and "future",
Hoerl argues that in the extensionalist framework it is tenseless
notions such as "before" and "after" that are
required. When hearing an auditory succession consisting of a
whizz-bang we don't first experience the whizz as present and
then (shortly after) as past-seeming:



> 
> 
> my experience is rather as of each sound occurring in turn, and my
> experience's taking this course is what constitutes my being
> aware of the whizz being followed by the bang. (Hoerl 2009: 8)
> 
> 
> 



In a later article Hoerl (2013b) suggests here that currently the two
most promising approaches to temporal experience are extensionalism on
the one hand, and representationalist variants of retentionalism. He
also suggests--also see Hoerl (2017)--that the
extensionalist view of temporal experience and the direct realist (or
"relationalist") account of perception are natural
partners. The representationalist stance on perceptual experience can
assist the retentionalist in a number of ways, as we saw in
 SS4.4.
 Hoerl is also right that anyone who adopts a realist stance with
respect to temporal experience and who also inclines to direct realism
will find the extensional view a natural and appealing one. If I see a
traffic light change colour then for a direct realist an object
undergoing change over an interval of time is being directly presented
to me, and the resulting perceptual experience will itself extend
through time, just as extensionalists claim. However, on the face of
it the extensional approach seems compatible with *other* views
concerning the nature of perceptual experience, such as the indirect
realism Dainton prefers one, or adverbialism to mention but
two--see Crane and French (2015 [2021]) for an overview of the
competing theories.



The form of extensionalism defended by Hoerl is distinctive in a
further way. As Hoerl notes (2013b: SS6), to account for the
difference between a succession of experiences and an experience of
succession it is commonly argued that the latter possess a distinctive
kind of *unity* that is absent from the former. Dainton, for
example, holds that contents occurring at different times are only
experienced as successive if they are bound together by his diachronic
co-consciousness relationship. Hoerl argues that this assumption is in
fact misguided, and that if we embrace extensionalism there is no need
to appeal to this or any other unifying relation. In explaining how an
experience of succession differs from a succession of experiences the
only factor extensionalist needs to appeal to is the limited temporal
span of our temporal awareness. Hoerl suggests that Dainton's
appeal to the non-transitivity of co-consciousness amounts to nothing
more than



> 
> 
> another way of stating the intuition behind the individuation argument
> that the maximum duration that individual temporal experiences can
> span is limited. (Hoerl 2013b: 406)
> 
> 
> 



It is not obvious that extensionalists can dispense with the services
of a diachronic unity relationship. Let's consider things from
the vantage point of Hoerl's favoured combination of
extensionalism and direct realism. Direct realists hold that
(veridical) perception involves two elements: an external
mind-independent object and an act or episode of perceptual
awareness--a perceptual experience occurs when our awareness
acquaints us with an outer object. In the synchronic case: it is
widely (if not universally) agreed that phenomenal unity is a real and
important phenomenon. My current visual and auditory experiences are
unified in a distinctive way, whereas my current visual experiences
and *your* current auditory experiences are not.



Synchronic phenomenal unity can be accounted for in different
ways--see Brook and Raymont (2017 [2021]) for further details.
One option is to hold that there is a unity relation which joins
experiences together. A second option is to say that experiences are
unified by virtue of being subsumed in a more encompassing experience.
A further option is to hold that experiential contents are unified
when they fall under a single act of awareness. The latter option will
be a natural one for direct realists, given their view of the role
awareness plays in ordinary perception. Direct realists who take this
stance on synchronic unity are, in effect, getting an account of
synchronic unity for free--it follows from a prior theoretical
commitment to a certain view of perception. But it remains the case
that the contents at any given time in a typical stream of
consciousness *are* unified in a distinctive way.



The same applies in the diachronic case. Anyone who combines the
extensional view with direct realism will presumably hold that our
temporal experience relies on acts of awareness which are themselves
temporally extended. But as in the synchronic case, the contents that
fall under these acts of awareness will be unified in a distinctive
way: their successive parts are *experienced together* rather
than separately. When Hoerl talks of "individual
experiences" it is presumably unified ensembles of this kind to
which he is referring. Phenomenal unity has not departed from the
scene, it is merely being explicated in a different way.



Moreover, phenomenal unity is not confined to the contents of
experience, it will also exist at the level of acts of awareness. In
the synchronic case, if consciousness has an awareness-content
structure all contents have to do in order to be phenomenally unified
is to fall under a single awareness at a give time. In the diachronic
case the situation is not so straightforward. An act of awareness
which extends across an interval of time will be composed of different
phases, and unless the successive phases of the extended acts of
awareness are themselves experienced together--in the manner
depicted in
 Figure 5.1
 above--we won't have experiences of succession.



To make matters more concrete let us focus on a temporally extended
episode of awareness **A**, which has sufficient temporal
extension to encompass a traffic light's changing from red to
green, but which does not stretch any further into the past or future.
We can represent this state of affairs schematically thus:
**A[red, green]**. Let's now narrow our focus and
consider two briefer sub-phases of this experience:
**A[red]** and **A[green]** corresponding to
the earlier and later phases of the experience we are considering.
Unless the earlier and later phases of **A** are
phenomenally unified our subject's stream of consciousness
consists of two entirely discrete experiences: **A[red]**
and **A[green]** experienced in succession but not
*as* a succession. In order for our subject to have a single
experience--an experience *of* succession rather than a
succession of experiences--it has to be the case that the red and
green lights are experienced together rather than separately. Adopting
a direct realist conception of perception doesn't eliminate the
need for a mental unity relation, it merely gets re-located or
re-described. Or so a critic might object.



For discussion of some further issues relating to extensional specious
presents see the supplementary document
 The Specious Present: Further Issues.


## 6. Hybrid Approaches


### 6.1 Extended Contents and Momentary Acts



Given that the retentional and extensional approaches continue to have
their defenders a not unreasonable conclusion to draw is that both may
contain an element of the truth so far as the nature and structure of
temporal consciousness is concerned. Given this it is not surprising
to find a number of writers proposing *hybrid* models
which--in differing ways--contain elements of both.



In his *Scientific Thought* (1923) C.D. Broad writes:



> 
> 
> There is no doubt that sensible motion and rest are genuine
> unanalysable properties of visual sensa. I am aware of them as
> directly as I am aware of the redness of a red patch (1923: 287)
> 
> 
> 



a clear commitment to realism. Later in the same work, in a much-cited
passage he elaborates thus:



> 
> 
> ... it is a notorious fact that we do not merely notice that
> something *has* moved or otherwise changed; we also often see
> something *moving* or *changing*. This happens if we
> look at the second-hand of a watch or look at a flickering flame.
> These are experiences of a quite unique kind; we could no more
> describe what we sense in them to a man who had never had such
> experiences than we could describe a red colour to a man born blind.
> (1923: 351)
> 
> 
> 



The account of the structure of temporal consciousness Broad went on
to develop in *Scientific Thought* is of a distinctive kind. It
is built on acts of awareness that are themselves momentary but which
apprehend contents distributed over a short interval of time. For
Broad a stream of consciousness consists of dense sequences of
momentary acts and extended contents, with the consequence that the
contents apprehended by neighbouring acts largely overlap. For anyone
who holds that consciousness has an awareness-content structure
Broad's basic approach may well look quite promising--and
many direct realists as well as sense-datum theorists fall into this
category. The sort of overlap Broad envisages is shown in
 Figure 6.1,
 where three momentary acts A1, A2, and A3 apprehend a succession of
auditory tones C-D-E-F, with each act able to apprehend two adjoining
tones.



![link to extended description below](broad-theory.svg)

Figure 6.1 C.D. Broad's Theory. [An
 extended description of Figure 6.1
 is in the supplement.]




Broad's theory has its merits, but it also gives rise to some
problems and puzzles. Let's suppose that during the experiencing
of the D-tone a brief flash of light is also experienced--in
 Figure 6.2
 below the flash is represented by the asterisk shape. This flash
falls under A1, and so is experienced by that awareness; it also falls
under A2, and so is experienced by that awareness. Hence the problem:
it looks as though the flash is experienced twice, when in reality it
would be experienced only once. In fact the situation is far worse,
because in Broad's model there are many additional momentary
apprehensions occurring between A1 and A2, each creating a different
experience. As Mabbott puts it:



> 
> 
> Nothing in my direct experience confirms this repetition. If it
> occurred it would obviously make listening to music or to continuous
> sentences a matter of the greatest complexity and difficulty. (Mabbott
> 1951: 161)
> 
> 
> 



Dainton (2000 [2006: 141]) also suggests that Broad's account is
afflicted by a problem of "repeated contents".



![link to extended description below](repetitions.svg)

Figure 6.2 Repetitions and Divergences.
[An
 extended description of Figure 6.2
 is in the supplement.]




A further problem stems from the fact that on Broad's account
the periods during which we are continuously aware of contents can
have a greater temporal extension than the contents themselves.
Returning to
 Figure 6.2
 the experience of the flash unfold over the very brief interval
*e* shown in the diagram. The duration *d* stretches
from A1 to A2 and corresponds to the entire period of time the subject
was aware of the flash. As can be seen the interval *d* is
considerably longer than *e*. Since contents that are
apprehended by acts of awareness appear to be present, this means
that--if Broad's account is correct--brief events are
experienced as present for considerably longer periods than they
actually are present. By allowing us to experience an interval in an
instant (or something close to it) Broad renders temporal experience
incapable of accurately reflecting the temporal properties of the
events we perceive. If our experience *were* misleading in this
sort of way it is difficult to believe we would not notice. For
further discussion of these aspects of Broad's model see Dainton
(2000 [2006: 6.2]), Tye (2003), Phillips (2010) and Rashbrook (2012,
2017).


### 6.2 Further Hybrid Variations



One way for extensionalists to embrace (after a fashion) the
structures elaborated by retentionalists is to agree that the latter
do exist, and do play a role in our cognition, but at an entirely sub-
or pre-conscious level. On this view, retentions (and perhaps
protentions) exist, but in the guise of neural mechanisms and
processes that do not directly feature in consciousness. Carlos
Montemayor (2013; Montemayor & Wittmann 2017) has defended this
position. Montemayor proposes that we distinguish the "sensorial
present" from "the phenomenal present". The
sensorial present represents stimuli as simultaneous, whereas the
phenomenal present has a temporal extension of around half a second up
to three seconds. Montemayor goes on to argue that it is a mistake to
think the cinematic, retentional and extensional models are mutually
incompatible. The cinematic and retentional models correspond to his
sensorial present, and whereas the (extensional) phenomenal present is
phenomenally conscious, the sensorial present is only
*access-*conscious in Ned Block's sense. Merino-Rajme
(2017) is impressed by the ingenuity of this proposal, but raises
doubts as to whether it is compatible with Block's conception of
what access-consciousness involves.



Thomas Sattig (2019c) suggested that in his *Raum und Zeit*
(1915) Anton Marty defended a hybrid model in which both retentional
and extensional elements figure in temporal experience. Marty's
position is certainly intriguing, but since it confines the experience
of change to momentary phases of experience it ultimately seems more
retentionalist than extensionalist in character.



In a recent paper Rick Grush (2016
 [Other Internet Resources])
 distinguishes two sorts of perceptual content: *A-ish* content
is structured in terms of past, present and future whereas
*B-ish* content is structured in terms of earlier than,
simultaneous and later than. Grush points out that in discussions of
temporal experience it is generally (if tacitly) assumed that the
character of temporal experience has the same character at all
temporal scales, over short intervals of time, medium intervals and
long intervals. But what if this is not the case? What if our
experience *isn't* scale invariant? Grush proposes that
at the larger temporal scales of seconds or minutes it is very
plausible to think that our experience is A-ish in character. If you
are watching an Olympic sprint, at around the mid-point some of the
race still lies in the future, some of it is in the past, and some of
it is happening now. But perhaps it is different at smaller sub-second
temporal scales, and this is what Grush proposes: our experience is
A-ish down to the scale of 200 msec, but beneath that it is B-ish:



> 
> 
> No point in this interval is singled out as a now bracketed by a past
> and future. Rather, within this interval events are represented as
> standing in relations of *earlier than*, *simultaneous
> with*, and *later than*. But at scales greater than this,
> this *B-ishly* structured interval of 200 msec effectively
> becomes the bulky *now* of *A-ish* experience.
> (Grush 2016
>  [OIR]:
>  8)
> 
> 
> 



Grush argues that holding that contents possess a B-ish character over
short intervals helps circumvent an otherwise serious "surplus
content" problem that Dainton (2000, 2008a) has directed against
retentional models.



Gerardo Viera also argues for a hybrid approach in which extensional
and retentional (or atomist) models both have important play, but
where neither applies universally, to all forms of temporal
experience. The grounds for this claim are scientific:



> 
> 
> empirical evidence suggests that temporal experience is fragmented and
> composed of many dissociable capacities to perceive the temporal
> structure of our world. (Viera 2019: 33)
> 
> 
> 



Viera's starting point is the current state of play in
neuroscientific investigations into how the brain manages to keep
track of time. The long-dominant assumption that the brain relies on
the regular beating of a single master-clock has been steadily
undermined. If the master-clock existed and its functioning were
disrupted by drugs or neural damage we would expect this disruption to
have a devastating global impact on an individual's time-related
abilities, but Viera points out that there are no known cases of
neural damage which *completely* eliminate a person's
ability to perceive time. Coming from the other direction the
hypothesis that timing and time perception depends on a multiplicity
of different neural mechanisms has plenty of empirical support. When
rapid transcranial magnetic stimulation (rTMS) is applied to the
frontal cortex the result is impaired timing in the second range; when
rTMS is applied to the cerebellum timing in the millisecond range is
impaired. Ingesting psylocibin has no effect on the ability to
perceive at timescales of less than 2 seconds, but severely impairs
perception at longer timescales.



If our brains use a multiplicity of very different neural mechanisms
when dealing with time then it is possible that the extensional model
applies to some forms of temporal experience and the retentional model
to other forms, Viera argues that this may well be the case. When it
comes to accounting for temporal perception at the sub-second level
for individual sensory modalities so-called *intrinsic timing
models* are currently influential, these rely on the dynamics of
temporally extended neural processes to encode time, rather than any
external clock. By way of an analogy, think of the way a pattern of
ripples on a lake carries information about the time that has elapsed
since a pebble was dropped. Viera suggests that any experiences this
type of extended neural process produces will themselves be temporally
extended in an extensionalist manner, with the mirroring constraint
will be satisfied: the temporal features of successive phases of the
neural process and the successive phases of the experience will
correspond exactly. However, extensionalists don't have it all
their own way. In the case of cross-modal perceptual order judgements
at the timescale of less than one second Viera points out that there
are cases where mirroring conspicuously fails. Experiments show that
if a short delay is introduced between a button-pressing and a flash
of light the two events seem to be occurring closer together in time
than they in fact are--in some cases the ordering of the stimuli
seems to be entirely reversed (Viera 2019: 39-40).



Viera draws an ambitious conclusion from these results: since the
mirroring constraint is violated



> 
> 
> we have a counterexample to extensionalism, and therefore neither
> atomism nor extensionalism can provide us with a general theory for
> how the temporal contents of experience relate to the temporal
> structure of experience. (2019: 41)
> 
> 
> 



It would be more accurate to hold that the cross-modal temporal order
judgement case presents a potential problem for extensionalists who
are committed to a very strict form of mirroring. Viera's
argument poses no threat to extensionalists who are prepared to
acknowledge that mirroring may sometimes fail to hold at shorter
time-scales.



On a number of occasions Ian Phillips (2010, 2018) has suggested that
a different sort of hybrid theory may well be worth taking seriously.
Phillips proposes that the extensional and retentional approaches have
more in common than has usually been realized: there are grounds for
thinking that both essentially depend on a form of *memory*.
The kind of memory Phillips has in mind is not the sort we can call up
hours, days or months after the event we are
recollecting--critics of the Reid-type memory theories are right
to point out that memories of this kind are too unlike perception to
figure in temporal experience. The relevant type of memory is what
James called primary or elementary:



> 
> 
> an object of primary memory ... never was lost; its date was
> never cut off in consciousness from that of the immediately present
> moment. In fact it comes to us as belonging to the rearward portion of
> the present space of time, and not to the genuine past. (James 1890:
> 646-7)
> 
> 
> 



Phillips argues that primary memory properly understood, is perceptual
in character, and so capable of playing a role in role in experiences
of succession by providing us with a direct link to the immediate
past. Phillips takes his "refined memory theory" to be a
memory-based version of extensionalism. But he also proposes that,
properly understood, Husserl's theory is very similar:
Husserl's retentions are also constitutively connected to the
past, and by virtue of that could not exist in a momentary episode of
consciousness lacking that connection to the past. Adopting this
perspective, Phillips argues, sheds valuable light on the entire
field. For it suggests that the fundamental division is between those
who those who claim



> 
> 
> that it is only *because* our experience is a process which
> unfolds in time that it can acquaint us with the temporal structure of
> reality as it does.... (Phillips 2018: 17)
> 
> 
> 



and those who deny this. Phillips proposes that if we view matters
thus



> 
> 
> ... theorists who we might initially conceive of as rivals,
> namely extensionalists such as Dainton, and retentionalists such as
> Husserl and O'Shaughnessy, do not obviously disagree on
> substance. (2018: 21)
> 
> 
> 



By way of further elaboration Phillips suggests the relation of
co-consciousness which Dainton invokes to unify earlier and later
phases of experience can itself be viewed as involving a form of
memory.



The suggestion that Dainton's co-consciousness relation could
amount to a form of memory is an interesting issue for future
discussion. That aside, Phillips' claim that there is a divide
of a fundamental kind between those who hold that experiences of
succession require a succession of experiences on the one hand, and
those who hold that experiences of succession do *not* require
a succession of experiences on the other, is very plausible.



In his discussion of Phillips' work Wolf (2021) finds much to
recommend, but suggests that in its current form it lacks a decisive
advantage over the more orthodox extensional and retentional
approaches. The solution, Wolf suggests, is to move in a more
dynamic--more Bergsonian direction--by finding a way of
incorporating Bergson's seemingly (but not really) paradoxical
claim that "duration is essentially a continuation of what no
longer exists into what does exist". Wolf suggests that once
this is done the result is a more appealing form of Bergsonian
extensionalism that has greater plausibility than the competing
versions, Phillips' included.


## 7. Anti-Realisms



Perhaps there is a more dramatic discrepancy between the actual
characteristics of our experience, on the one hand, and our
*beliefs* about these characteristics on the other, than
anything we have considered up to now. True, we do talk as though we
see things move (and more generally, perceive change), and doubtless
this talk reflects our beliefs, but perhaps our beliefs are simply
wrong. Perhaps our immediate experience is in reality entirely
motion-free, and our streams of consciousness radically fragmented,
but since we do not believe our experience is like this, we do not
talk as though it is.



A position along these lines has been advocated by Dennett. If asked
whether our typical visual fields are fully continuous, even when one
of our eyes is closed, most of us are inclined to answer in the
affirmative: when we look at (say) a white wall, we see an
uninterrupted expanse of white. In such cases we are unable to detect
a beachball-sized fuzzy dark expanse lying just to one side of the
central axis of vision. But the physiology of the eye suggests there
should be a "blind spot" at that location, corresponding
to the region of the retina occupied by the optic nerve which is
devoid of light-sensitive cells. As for why we do not detect a blind
region in our visual field, the standard--and on the face of it,
plausible--answer is that our visual systems engage in some
"perceptual interpolation" or *filling-in*: our
brains extrapolate from the stimuli reaching the light-sensitive cells
in the region of the retina immediately surrounding the blind-spot,
and fabricate experience to fill the relevant region of the visual
field accordingly.



Dennett points out that there is alternative to this account. Rather
than "making up" experience in this manner, perhaps our
brains simply fail to *notice* that there is a lack of visual
information deriving from the hole region: after all, an absence of
information is not the same thing as information about an absence.
Never having received information from this region, the brain simply
works on the assumption that nothing special is going on there:



> 
> 
> The brain doesn't have to "fill in" for the blind
> spot, since the region in which the blind spot falls is already
> labelled (e.g., "plaid" ... "more of the
> same"). (1991: 335)
> 
> 
> 



In effect, since we have a *belief* about what the blind region
contains--typically, "more of the same"--why
should the brain go to the trouble of generating experience as well?
Dennett goes on to suggest that this treatment of spatial holes can
plausibly be extended to temporal holes (gaps in the continuity of
experience) also. Our visual experience is constantly interrupted by
our eyes darting about during saccades. We don't notice the
resulting holes or gaps in our experience, but they don't need
to be filled in because we're not designed to notice them. More
generally:



> 
> 
> One of the most striking features of consciousness is its
> *dis*continuity--as revealed in the blind spot, and the
> saccadic gaps, to take the simplest examples. The discontinuity of
> consciousness is striking because of the *apparent* continuity
> of consciousness. (1991: 356)
> 
> 
> 



Although Dennett himself concentrates on explaining why we are
inclined to describe our experience as continuous if it is really
discontinuous, the approach can be extended to the immediate
experience of change, or so Chuard argues (2011: 17) Suppose the
"succession of static snapshots" conception of experience
as proposed by the cinematic theorist is correct. Provided the
contents and temporal arrangement of these static snapshots are enough
to convince our brains that we are perceiving motion and change, we
will inevitably *believe* that this is what we are perceiving,
and hence *describe* our experience in such terms. Isn't
this all that we are required to explain? For Dennett and Chuard
nothing further is needed.



As noted in
 SS1.3
 it is possible to be a realist about the experience of change and
succession but an anti-realist about the dynamic features that some
realists claim to be a pervasive feature of our experience. Thomas
Sattig falls into this camp. Sattig is a realist about the experience
of change and succession:



> 
> 
> ... I do not merely *infer* that the leave has moved, from
> memories of previously experienced momentary leaf-states. I just
> *see* that motion occurs. (Sattig 2019a: 275)
> 
> 
> 



Sattig doesn't reject *all* forms of flow, and has
developed an account of it grounded in phenomenal
*replacement*:



> 
> 
> ... I see that each momentary leaf-state is immediately replaced
> by another one like water flowing through a river bed, where each
> portion of water is immediately replaced by a new portion. (Sattig
> 2019b: SS1)
> 
> 
> 



In reducing the experience of motion to successions of momentary
perceptions of objects at different locations he appreciates that some
realists will find that his account fails to do justice to the dynamic
nature of phenomenal flow:



> 
> 
> Primitivists about the phenomenal *whoosh* of flow will not
> accept this phenomenological analysis, nor will they accept any other
> ... But I have yet to encounter an alternative phenomenological
> description that reaches substantially beyond the usual, opaque
> flow-metaphors. (2019b: SS4)
> 
> 
> 



Others are still more sceptical, arguing that realists who believe in
experiential flow or passage are deluded about the character of their
own experience: flow isn't a real feature of our experience, we
merely (and falsely) believe that it is. Hoerl (2014) adopts this
line, arguing that it is a mistake to suppose that the experience of
seeing a moving object involves anything more than seeing the object
at a succession of different locations--also see Braddon-Mitchell
(2014). In a similar but more general vein K. Miller, Holcombe, and
Latham (2020) suggest that we may well be inclined to attribute
dynamic features to our experience which it in fact lacks, and propose
two cognitive mechanisms which may underlie this inclination.


## 8. Temporal Consciousness and the Metaphysics of Time


### 8.1 Competing Conceptions of Time



If there are very different accounts of the nature of temporal
experience, the same applies to time itself--the time which
exists in the wider physical universe, rather than time confined to
human consciousness. Let us take a brief look at these differing
conceptions before considering the complex issue of how universe-time
and experienced-time are related.



One central issue concerning universe-time can be encapsulated is this
simple question: "Does time pass?" Temporal passage can be
characterized in a number of ways, but at the very least passage is
associated with the idea that the present is metaphysically privileged
and steadily advancing, and this advance entails that future times
will become present, that present times and events will become past,
and that past times become ever *more* past with every passing
moment. But while few deny that time seems to pass--and indeed,
that this passage is (along with dimensionality) the most obvious
difference between time and space--there are many who have denied
that time really *does* pass. Of these a few share
McTaggart's view that time cannot pass because time does not
exist.



A more popular view, these days at least, is the view that while time
certainly exists, it is more akin to space than it superficially
seems. Proponents of the four-dimensional "block
universe"--also known as *eternalism*--hold
that there is no ontological distinction between past, present and
future, and that all times are equally real. They further hold that
there is no unique privileged present time, and *a fortiori*
that there is no such thing as a *moving* present. Block
theorists face a significant challenge: Why does time seem to pass if
it doesn't? Part of the explanation lies in the way our memories
accumulate, and intentions and decisions translate into actions (see
Ismael 2011, 2013, 2016). Another part of the explanation lies in the
character of our experience. Time *per se* may not pass or
flow, but there is something akin to passage and flow in our immediate
experience--*phenomenal passage* we can call it--or
so many believe.



The block conception of time has its advantages. It has an appealing
simplicity, and accords well with Einstein's relativity
theories, to mention but two. But the rejection of objective temporal
passage is not to everyone's taste, and other conceptions of
time also have their advocates. The main contenders are depicted in
 Figure 8.1
 below. At the opposite extreme to the 4-D block view is
*presentism*, the doctrine that concrete reality is confined to
the momentary present. Presentists deny any reality to the past or
future. Coming in between these extremes is the *growing block*
model. According to the latter, the past is real but the future is
not, and the sum total of reality is gradually increasing, by a
process of moment-by-moment absolute becoming. On this view the
present is merely the most recent addition to reality; it is also the
interface between being and non-being. The *moving spotlight*
model is in one respect akin to the standard block model: it accords
reality to all times and events, including those yet to occur. It
differs from the latter by virtue of the fact that it incorporates
objective passage into the universe, in the shape of a privileged (and
constantly advancing) present--indicated by the blue line.



![link to extended description below](four-conceptions.svg)

Figure 8.1 Four conceptions of the
large-scale composition of the universe. [An
 extended description of figure 8.1
 is in the supplement.]




What McTaggart labelled the "A-series" runs from the
distant past, up through the recent past to the present, and then on
to the future. The "B-series" is the series of positions
which runs from earlier to later, and vice-versa. Properties such
*being past*, *present*, or *future* are often
known as "A-properties", whereas *being earlier
than*, *being later than*, and *being simultaneous*
are known as "B-properties" or "B-relations".
The block or eternalist conception of time is also often called
"the B-theory". The opposed dynamic conceptions of time
are often called "A-theories".



How do these different metaphysical conceptions of time accord with
our competing realist accounts of temporal consciousness? One point
seems more obvious that most. If reality is confined to a momentary
present in the way presentists usually maintain, then it is difficult
to see how any form of the extensional approach can be true. Our
immediate experience cannot extend through time if time itself has no
extension; if earlier and later stream-phases are experienced
*together*, in the way extensional models require, then it
seems very plausible to suppose that these phases must both exist. Or
to put it another way: an experience which no longer figures in the
sum total of reality is not in a position to be part of the same
unified state of consciousness as an experience which *does* so
figure, any more than a non-existent brick can help hold up a wall. By
contrast, since retentional theorists have the option of holding that
our experience of time *takes* no time--objectively
speaking--their position looks to be entirely compatible with
presentism, and similarly for the cinematic
 model.[19]
 As for the 4-D block conception, it looks equally compatible with all
the main views of temporal consciousness. The retentional
theorists' momentary specious presents can exist in universes of
this sort, as can those of cinematic theorists, but so too can the
non-momentary specious presents to be found in extensional models.


### 8.2 The Argument from Experience



Does the character of temporal experience have any implications for
the nature of time *per se*? Could the dynamism we encounter in
our temporal experience be sign of temporal passage or even a product
of it? Does it bolster the A-theorist by providing evidence that time
really does pass? Claims that the passage of time features in our
experience are not difficult to find.



> 
> 
> The best reason to believe that time passes is simply that we
> *find* passage, that we are immediately and poignantly involved
> in the jerk and whoosh of process, the felt flow of one moment into
> the next. (Williams 1951: 466)
> 
> 
> 



> 
> 
> I cannot survey all the motivations philosophers have had for the
> moving spotlight theory. But the motivation that I like best appeals
> to the nature of our conscious experience. Of all the experiences I
> will ever have, some of them are special. Those are the ones that I am
> having NOW. All those others are ghostly and insubstantial. But which
> experiences have this special feature keeps changing. (Skow 2009:
> SS5)
> 
> 
> 



> 
> 
> I find it impossible to relinquish the sensation of a flowing time and
> a moving present moment. It is something so basic to my experience of
> the world that I am repelled by the claim that it only an illusion or
> misperception. (Davies 1995: 275)
> 
> 
> 



> 
> 
> There is hardly any experience that seems more persistently, or
> immediately given to us than the relentless flow of time. (Schlesinger
> 1991: 427)
> 
> 
> 



Given that there is more than one conception of what temporal passage
itself amounts to the relationship between this sort of passage and
temporal experience will not be straightforward. However, Le Poidevin
has suggested that there is a general argument which connects the two,
he calls it "the argument from experience" (Le Poidevin
2007: SS5.1) and it can be formulated along these lines:


1. We have experiences that are seemingly of the passage of
time.
2. The best explanations of this sort of experience all rely on the
passage of time being an objective feature of reality
3. Therefore temporal passage is a real and objective feature of
reality.



As Le Poidevin points out, a variety of quite different experiential
considerations have been construed as linked to the passage of
time--e.g., the perception of change and motion, the (seeming)
confinement of the present--so there is a cluster of different
issues which need to be investigated. Useful critical appraisals of
these ongoing debates include Baron et al. (2015), Deng (2013, 2018),
Frischhut (2015), Hoerl (2014), Prosser (2007, 2012, 2013, 2016).



Among B-theorists who want to deny that time really does pass one
popular strategy is to focus on the second premise of argument from
experience and find alternative explanations for experiences that are
suggestive of passage. L.A. Paul has argued there are well-known
results from psychology and the cognitive sciences which are
potentially of great use to B-theorists seeking such
explanations--see Paul (2010) and also Le Poidevin (2007:
SS5.5). In the case of apparent motion, for example, two
stationary flashing spots on a computer screen will be seen to be
moving smoothly back and forth, provided the spots are sufficiently
close together and the rate of flashing is not too fast or too slow.
In a similar fashion, the moving images on a cinema screen are a
product of the ways in which our brains process the sequences of
static images being projected onto the screen. Paul suggests that
there is a more general lesson here: much of the dynamism we are
naturally inclined to suppose exists in the world in reality is being
fabricated in our brains:



> 
> 
> Occam's razor suggests that the flow or animated character that we
> often refer to as "motion" is just a mistake. Motion is
> simply the change of location of a persisting object, and the flow or
> animated character that we notice and identify with motion is merely
> an effect of the brain. (Paul 2010:
>  358)[20]
> 
> 
> 



Simon Prosser is a B-theorist who has on a number of
occasions--e.g., Prosser (2000, 2007, 2012, 2013,
2016)--urged adopting a quite radical response to the argument
from experience. For Prosser the idea that temporal experience could
lend support to any form of temporal passage doctrine is radically
misconceived: it is in fact quite impossible. A-theories of time are
metaphysically incoherent and temporal passage is impossible.
A-theoretic properties cannot exist, and cannot even be represented in
consciousness.



In arguing against A-theories Prosser develops and deploys "the
Detector Argument". Smoke detectors can reliably detect the
presence of smoke, Geiger counters can detect radiation, could there
be a physical device capable of detecting temporal passage, one (say)
that is equipped with a bulb which lights up when passage is found?
Prosser argues that such a device is impossible: "there could be
no physical system that would detect the passage of time"
(Prosser 2016: 34). The reason for this is simple and straightforward:
although defenders of A-theories of time believe that time passes,
they don't usually hold that passage makes a *detectable
physical difference* to objects and events, and given this it is
hard to see how any physical device could detect the existence of
temporal passage. Prosser points out that the positions on the nature
of the relationship between mind and body that are currently taken
seriously in contemporary philosophy all posit very close connections
between minds and brains: either minds *are* brains, or the
mental causally depends on brain processes down to their last detail.
Given the nature of this relationship "if no physical system can
detect the passage of time then neither can the human mind"
(Prosser 2016: 35) and it is impossible for temporal passage to
register in human experience.



Prosser's claim that passage makes "no physical difference
to events" is questionable on a number of counts. Some
A-theorists equate temporal passage with the
*coming-into-being* of events--presentists and growing
block theorists fall into this category. A-theorist of this kind will
not find Prosser's argument persuasive. They will point out that
if time did not pass the physical universe as we know it simply would
not exist. Nothing would happen, there would be no physical
interactions between events, no event would cause another
event--not if causation involves an earlier event bringing a
later event into existence. Indeed there wouldn't even any
events, since events are occurrences in time, and time for the
A-theorist essentially involves passage. For more on this line of
response see Phillips (2016), Skow (2018) and Dolev
 (2019).[21]



Even if we set aside A-theories of this kind problems remains. Prosser
notes:



> 
> 
> Arthur Eddington, who was aware, as long ago as 1928, that no physical
> system could detect the passage of time, drew the conclusion that
> "consciousness, looking out through a private door, can learn by
> direct insight an underlying character of the world which physical
> measurements do not betray" (Eddington 1928: 91) These days,
> however, I do not think we can regard views of this kind as
> acceptable. (Prosser 2016: 35)
> 
> 
> 



However, this issue is less straightforward than Prosser suggests. In
*The Nature of the Physical World* Eddington certainly did
claim that the material universe is dynamically temporal in a manner
which physics does not recognize, and he also held that we know this
because our consciousness provides us with some access to the real
nature of the physical world. But in making these claims he
wasn't relying on some sort of mystical revelation concerning
the true nature of things. Eddington defended a version of
panpsychism, a fact which makes him something of a hero for
contemporary panpsychists--see Strawson (2006) and Goff
(2017).



Eddington, following in Russell's footsteps, held that physics
only reveals the causal and structural properties of physical things,
it tells us nothing of their intrinsic nature--about the inner
nature of the stuff they are made from. If we assume, as seems
plausible to many, that physical things must have *some*
intrinsic nature, then if physics is silent in this regard there is an
important consequence: the hypothesis that the physical processes in
our brains associated with consciousness have an *experiential*
intrinsic nature will be compatible with everything physics has to
say. In the light of this, Eddington suggests that it would be rather
bizarre to adopt a different hypotheses and take the intrinsic nature
of the relevant brain processes to be *non*-experiential:



> 
> 
> It seems rather silly to prefer to attach it [consciousness] to
> something of a so-called "concrete" nature inconsistent
> with thought, and then to wonder where the thought comes from.
> (Eddington 1928: 259)
> 
> 
> 



Since there is nothing special about the material in our
brains--they're composed of the same sort of basic physical
ingredients as mountains, oceans and trees--then it seems
plausible to conclude that if brain-stuff has an experiential
intrinsic nature then all physical stuff
 will.[22]



It's true that Colin McGinn once characterized panpsychism in an
utterly dismissive way:



> 
> 
> a complete myth, a comforting piece of utter balderdash ...
> isn't there something vaguely hippyish, i.e. stoned, about the
> doctrine? (2006: 93)
> 
> 
> 



It's also true that panpsychism has its share of
problems--in common to all the other attempted solutions to
problem of how consciousness and the physical world are related. But
it's also the case that in contemporary philosophy of mind
circles panpsychism has a respectability it hasn't had for some
time--see Bruntrup & Jaskolla (2016) and Seager
(2019).



Returning to the detector argument, if Eddington's response has
to be treated with respect, then Prosser's conclusion that no
physical system can possibly detect any form of temporal passage looks
to be premature. If our experiences are revealing the inner intrinsic
natures of certain neural processes--as panpsychists
maintain--then if these experiences possess dynamic flow-type
properties, then these properties will belong to the physical world.
Neural processes, are after all, physical processes. In which case
there is at least one way in which a physical system can detect one
form of temporal passage.



This point also has a more general metaphysical significance. If
panpsychism is true then everything in the universe is enjoying some
form of consciousness. If (as many suppose) consciousness is
essentially temporal, then if panpsychism is true everything in the
universe will be enjoying a temporal form of consciousness. In which
case the competing accounts of the structure of temporal experience
are competing accounts of the nature of reality as a whole--in
much the way Bergson suggested, a century or so ago.