## 1. The history of the term



The received view, which takes the notion to originate in Arabic
philosophy, traces back to an article by the phenomenologist Herbert
Spiegelberg, originally published in 1933 (for a translation of a
revised version, see Spiegelberg 1976). It turns entirely on
philosophical terminology: it only considers texts that use cognates
of 'intention' in a specific technical sense, that of a
mental act's *being directed at* or *referring to*
something, in contrast with a usage that applies exclusively to
practical contexts, where an agent intends to do something.
Spiegelberg claims that before the high scholastic period, uses of the
Latin *intentio* were exclusively practical and so have no
bearing on the problem of the intentionality of mental states more
generally. The closest antecedents, he claims, are the Arabic
*ma'na* and *ma'qul*, which were translated
into Latin in the high scholastic period by *intentio*.



Even when considered simply as a history of the terminology, this
account is seriously mistaken. Late scholastic discussions often cite
Augustine, in particular Book XI of his *On the Trinity*, in
which *intentio* plays a central role. And while Augustine does
identify *intentio* there with will (*uoluntas*) and
even love (*amor*), he does not have practical concerns
exclusively or even primarily in mind. On the contrary, his focus is
on cognition, starting with vision and continuing on with memory,
thought, and self-knowledge. It is just that he thinks that in order
to account for the directedness of these states, their analysis must
ultimately include a certain practical element, rather than the other
way around, where all practical attitudes must be explained in terms
of cognition. Augustine argues that vision and perception generally
cannot be analyzed simply into subject and object (as on
Aristotle's account). That would leave out something essential,
which is needed to direct the sense to the perceptible object and keep
it fixed on it. Augustine identifies this third element as the
perceiver's *intentio*, which he characterizes as a kind of
striving or will. It is precisely because a trio of factors are
required, in fact, that he believes psychology can be useful to
Trinitarian theology. Since humans are made in God's image, each
human (or more precisely, each "inner man") must also
replicate God's triune structure. The role *intentio*
plays in cognition is parallel to that of the Holy Spirit, mediating
between the Father and the Son: it mediates between the object and the
cognitive faculty. Later scholastics were thus right to cite
Augustine's use of *intentio* in discussions of
cognition, establishing a direct link to late antiquity, independent
of the contributions of Arabic philosophy, in the history of what
Spiegelberg called "extra-practical" intentionality.



Augustine, moreover, is adapting and developing earlier Greek views.
In Book XII of his *Literal Commentary on Genesis*, he offers
an extensive analysis of vision that relies heavily on Stoic theory.
In both theories, vision depends on the active role of the
perceiver's *pneuma* (Greek) or *spiritus* (Latin),
"breath" in its original meaning and for the Stoics a kind
of hot gaseous body, but for Augustine something immaterial. (The same
words, not insignificantly, are used in the Christian scriptures for
the Holy Spirit). Vision occurs when the *pneuma* extends
through the optic nerve and the eye to the object, either by reaching
out through the pupil to make contact with the object directly (as on
Augustine's theory) or by pricking and tensing the intervening air
beginning at the pupil into a cone with its base at the object (as on
the Stoic theory). The words that the Stoic Chrysippus uses for the
extension of the visual cone to the object are the Greek verb
*enteinein* and noun *entasis* (Diogenes Laertius VII
157), which are cognate with the Latin *intendere* and
*intentio*. So if our goal was to find not just a continuous
transmission of technical terminology for intentionality, but cognates
of *intentio*, we could trace it back at least to Greek
theories of vision in the third century bce,
if not still earlier extromission theories of vision. (For further
discussion of Augustine's theory, as well as the history of the
terminology, see Caston 2001.)



Other expressions and figures of speech familiar to us from modern
discussions of intentionality can be found in ancient philosophy, even
though we cannot trace a continuous connection from them to our own
usage. Throughout antiquity, for example, we find the antithesis of
'presence in absence' (*paron apon*) to
describe the way a mental state can make something
"present" to the subject that is nevertheless absent from
the current surroundings and perhaps even from reality altogether.
Aristotle mentions such presence in absence explicitly as an
*aporia* or difficulty that must be resolved (*On Memory and
Recollection* 1, 450a25 ff.). Certain Stoics speak of immanent
objects of thought, items that are literally present "in
thought" (*ennoemata*). Later thinkers use the
phrase 'existing in mere thoughts alone' (*en psilais
epinoiais monais*) to characterize merely intentional objects,
which do not exist in reality. Even the metaphor of directedness
- of aiming the mind at something (*intendere animum
in*), like an arrow - can be found in ancient texts. In
Plato's *Cratylus* (420b-c),
Socrates
suggests that the word for belief, *doxa*, derives
etymologically from the word for bow, *toxon*: it "goes
toward" each thing and how it is in reality. Socrates then
extends this analysis to the vocabulary for deliberative states: the
word for plan, *boule*, for example, derives from the word
for shot, *bole*. The metaphor is repeated again in the
*Theaetetus* (194a): someone who
believes falsely is "like a bad archer who, in shooting, goes
wide of the mark and errs".


## 2. The history of the problem



A history of terminology, though, even when done correctly, tracks the
wrong items. The same technical terms are often used to express very
different concepts: just consider the philosophical usage of terms
like 'substance', 'matter', or even
'concept' itself. Conversely, the same concept is often
expressed by different terms, some of which may not be technical at
all, a situation that is especially likely at the beginning of inquiry
into a subject. So if terminology is to be used as evidence, much more
must be brought into consideration - simple word searches will
not do.



The terminology, moreover, holds little interest in its own right. In
order for a history to be philosophically illuminating, it should
focus on the concept of intentionality itself or, better still, the
divergent conceptions of intentionality that philosophers have had and
their resulting disagreements. These differences afford us the
greatest perspective on our own presuppositions and preoccupations, as
well as revealing paths and solutions we might not otherwise have
considered. There is thus no need to settle on a single conception as
*the* concept of intentionality at the outset, which would in
any case only produce a Whiggish history, of development towards and
deviations from some favored, but undoubtedly idiosyncratic view. On
the contrary, we should take the opposite approach: substantive
disagreements between philosophers are potentially the most
instructive philosophically.



A philosophical history would therefore do better to focus on the
history of the *problem* of intentionality: the difficulty,
that is, of providing a philosophically adequate account of the nature
of intentionality in light of its various peculiarities, whatever
terms may have been used to express it. Such an approach not only
allows room for different theories of intentionality, but also
divergent conceptions, as well as attempts to dissolve the problem,
either by dismissing the phenomenon entirely or by denying that there
is any genuine difficulty involved. A history of intentionality that
did not include a Parmenides or a Quine would not be very informative,
especially if we are trying to understand the difficulty and what is
at stake.



The problem of intentionality is the problem of explaining what it is
in general for mental states to have content, as well as the
particular conditions responsible for specific variations in content.
The difficulty of providing such an account lies in explaining why
mental states often seem to violate familiar entailment patterns
(whether or not we take such violations to be criterial of
intentionality). To begin with, the content of many mental states does
not correspond with what is in the world: what we imagine may not
exist, our beliefs may be false, our desires may go unfulfilled. To
put it more paradoxically, a mental state may be about something, even
if there isn't any such thing in the world. This is one of a
number of peculiarities that prove difficult to account for, and which
are sometimes thought to pose a particular stumbling block for
naturalistic approaches to the mind. As Wittgenstein once quipped, you
can't hang a man unless he is there, but you can look for him
even if he's not, or even if he does not exist at all
(*Philosophical Investigations* 1.133, SS462). There are
other peculiarities as well, concerning our ability to focus
selectively on certain aspects of objects, without having others in
mind. For example, while I cannot greet a person without greeting a
person of some particular height, I can think of a person without
thinking of a person of any particular height. I can also entertain
different attitudes to the same object at the same time, depending on
the aspect under which I consider it. So I might believe that the
Morning Star is a star but that Venus is not one, despite the fact
that Venus *is* the Morning Star; yet for just the same reason,
we cannot land a space probe on the one without thereby landing it on
the other. These and other difficulties form a loose family of
phenomena that give rise to the problem of intentionality. Different
philosophers may regard these phenomena differently, perhaps focusing
on some but not others, or even excluding some as not belonging
together with the rest. A philosophical history should be generous
about such differences: what is important philosophically is that a
philosopher recognizes that some of them pose a difficulty, at least
*prima facie*, in accounting for mental states. (For further
discussion of the methodology, see Caston 2001)


## 3. Before Plato



Parmenides of Elea (early 5th century bce) is
arguably the first Greek philosopher to have focused on the
problematic nature of intentionality. His poem (transmitted under the
title *On Nature*) offers a startling revelation of the
allegedly true nature of reality and appearance, in which the narrator
is instructed by a goddess that "you cannot grasp or express
what is not - it cannot be accomplished" (B2), for
"thinking cannot be found apart from what is, upon which its
expression depends" (B8.35-36) and "what can be said
and thought must be what is" (B6). The Greek for the phrases
'what is' and 'what is not' are notoriously
ambiguous. But if, as many interpreters maintain (see Owen 1960; Furth
1968), it should be construed here either in terms of (*a*)
what does or does not *exist*, or (*b*) what *is*
or *is not the case*, or perhaps (*c*) some fusion of
the two, then the goddess is denying the possibility of thinking or
speaking either about nonexistent objects, or about nonfactual
states-of-affairs, or both, on the basis of the following intuitions.
If one is to think or express anything at all, there must *be*
something that one is thinking or expressing (thus quantifying in).
But what is not, by hypothesis, *is not there* to be thought of
(cf. B3), since either it does not exist or is not in fact the case;
and if there isn't anything there to be thought of, then we must
not be thinking of anything either. Parallel problems are supposed to
arise in the case of speech, for statements concerning a nonexistent
or for false statements.



Concerns about non-existent objects or non-factual states of affairs
are not explicit in Parmenides' poem, though -
unsurprisingly, the goddess does not give examples of what she is
proscribing. This leaves room for other construals of 'what is
not', such as the view that it always requires completion or
specification as 'what is not *F*' for some value
of *F*, so that 'what is not' raises concerns about
negative predication instead, especially in explanatory and
cosmological contexts. But of course the precise nature of the
difficulty here is not spelled out either, so speculative
reconstruction is required. In any case, the goddess herself seems to
use negation and the phrase 'what is not' quite freely,
though perhaps this is just symptomatic of her liminal position at the
borders of Night and Day (B1).



Whatever Parmenides intended, it is clear that the subsequent
reception of his poem is concerned precisely with the problem sketched
above about what does not exist and what is not the case. Numerous
proscriptions similar to the goddess's are reported in the
remainder of the 5th century, though offered by philosophers with
quite different motivations and agendas, including Protagoras,
Gorgias, the author of pseudo-Hippocratic treatise *On the
Art*, Anaxagoras, Metrodorus of Chios, Euthydemus, Cratylus, and
Antisthenes. In many of these cases, the denial is explicitly
formulated as a rejection of the possibility of falsehood, of thinking
or speaking of what is not the case.



The sophists Protagoras and Gorgias are of particular interest.
According to Plato, Protagoras held that one cannot believe what is
not and that whatever one experiences is true (*Theaetetus*
167a). This fits snugly with Protagoras'
widely attested doctrine that each human being is "the measure
of all things," which, on any interpretation, excludes the
possibility of error. But Protagoras' endorsement reveals an
interesting subtlety in the Parmenidean thesis that what is not cannot
be thought about - or more positively, the thesis that if
something is had in mind, it must be. The goddess in Parmenides'
poem uses this thesis in a negative fashion, moving from the
assumption that certain things 'are not' to the
paradoxical conclusion that we cannot actually think about them
either. But one might equally use it in a positive fashion, as
Protagoras seems to have done, to move from the assumption that we
*can* in fact think of such things to the conclusion that they
must in fact 'be', i.e. exist or obtain, after all. In
itself, the Parmenidean thesis only makes a conditional claim, and
*prima facie* it seems open to employ either *modus
tollens* or *modus ponens*. Depending on whether one
retains commonplace assumptions about what we can think or about what
there is in the world, the Parmenidean thesis can lead to either a
bloated ontology or a very restricted psychology.



Gorgias challenges this thesis in his treatise *On Not Being*
(preserved in two slightly different versions in the
pseudo-Aristotelian *On Melissus, Xenophanes, and Gorgias* and
in Sextus Empiricus' *Adversus Mathematicos* VII 65 ff.).
It takes direct aim at Eleatic assumptions, and especially those of
Parmenides, by arguing that (i) there isn't anything; (ii) even
if there is something, it cannot be known; and finally, (iii) even if
something can be known, one could not inform anyone of this. The
second part is of particular interest, since Gorgias offers a
*reductio ad absurdum* of the Parmenidean thesis, especially
when deployed in the positive way we have just seen in Protagoras.
Given that we obviously can have in mind, for example, a chariot-team
racing on the sea - in fact, just by reading this, you have put
it in mind - it should follow from the Parmenidean thesis that
there *is* a chariot-team racing on the sea; but (*pace*
Protagoras) plainly there is not. If both these intuitions are
maintained, the only option left is to reject the Parmenidean thesis
itself: it is *not* the case that one can only think or speak
of what is - thought is not so tightly bound to reality. Gorgias
immediately goes on to argue for a sceptical conclusion, on the
grounds that we have no basis for telling which mental states
correspond to reality and which do not, and so cannot know anything at
all. But this further argument rests on having shown that our ordinary
intuitions about what we can think and what exists or obtains together
undermine the Parmenidean thesis. (For further discussion, see Caston
2002*a*)



Why should anyone be tempted by the Parmenidean thesis in the first
place? A simple intuition may lie behind it, namely, that thought
consists in a *direct relation* to what is thought about (and
*mutatis mutandis* for other mental states and what they are
about). For given that a relation cannot obtain unless all its relata
exist or obtain, it will follow that we cannot ever think of what does
not exist or obtain ("what is not"). To the extent that
this direct relational model has a grip on us, we will be forced to
either Parmenidean or Protagorean conclusions. In fact, we can
reformulate these assumptions together as an inconsistent triad (using
'thought' schematically for mental states more generally,
and allowing for the ambiguity between 'exists' and
'obtains'):


1. Thought consists in a direct relation to what is thought
about.
2. No relation can obtain unless all its relata exist/obtain.
3. Sometimes we can think about what does not exist/obtain.



Each of these theses possesses a certain intuitive appeal. But taken
together, they are inconsistent, and so at least one has to be given
up. This does not entirely force our hand, however, since any two of
the three are mutually consistent. So there is still room for
disagreement among the disputants. As we have seen, some 5th century
thinkers, including Parmenides himself (on some interpretations) chose
to maintain (A) and (B), and reject (C). But if this seems too costly,
as it does to most people, one would need to reject one of the other
two theses instead. An obvious candidate for rejection is (A), that
thought consists in a direct relation to what is thought about. But
there are different ways of going about it. Someone could simply (i)
reject a relational analysis altogether. But one could also reject (A)
while continuing to accept a relational analysis, so long as (ii) it
involves a relation to *something else* other than what is
thought about. Much of the subsequent discussion in ancient philosophy
can be seen as an attempt to pursue the latter strategy, (ii), by
finding a suitable intermediary: for example, certain Platonists
appeal to Forms; Aristotle appeals to changes within our body that
serve as internal representations; the Stoics from Chrysippus onwards
appeal to abstract semantic objects like propositions; and Epicurus
appeals to parts of the surfaces of bodies. A third main option,
though, would be to retain the direct relational model in (A)
unchanged, while also preserving the phenomenological intuition in
(C), and instead abandon the metaphysical assumption in (B), as the
earliest Stoics did. Whenever one thinks, these Stoics insist, there
*is* something that one is thinking about; but it needn't
be anything that *exists* or *obtains*. On this Stoic
view, there are things that do not exist or obtain, which can serve as
intentional objects of thought and other mental states.


## 4. Plato



Throughout his dialogues, Plato emphasizes the relational character of
various mental states: sight, hearing, touch and perception generally,
memory, belief, knowledge, concepts, speech, love (*Tht.*
152c, 160a-b,
163e, 188d-189b;
*Rep.*
V, 476e, 478b;
*Parm.* 132b-c;
*Soph.* 262e,
263c; *Symp.* 199d).
In each case, Socrates (or the other main
speaker) asks whether the mental state in question is "of
something or of nothing", and the interlocutors agree that it is
always *of something* - it is impossible for such a state
not to be of anything at all. In the *Charmides*, Socrates gets
Critias to agree to something stronger, namely, that many of these
states - seeing, hearing, and other forms of perception, desire,
intention, love, fear, and belief - must have an object
*other* than themselves; and he suggests that it would be odd
if knowledge were not like this as well (167c-168a).
But in this
regard, mental states do not differ from other relatives, as he
himself emphasizes: Socrates sometimes adds nonintentional cases, such
as siblings, parents and children, and doubles and halves, in order to
illustrate his point. In some of the passages above, Socrates follows
up this question with a further one, which has bearing only for the
mental states, namely, whether they are always of something
"that is" rather than something "that is not".
Although the speakers readily agree that these states must always be
of something that is, the problem of intentionality already looms,
merely by his raising the possibility that on occasion some states
might be of what is not, either of what is not the case or of what
does not exist. In the *Philebus*, this alternative is
explicitly taken up: just as one can believe something without that
belief being of anything that ever was, is, or will be, so one can
feel pleasure about something, or fear, anger, and so on, even if it
is not about anything that ever was, is, or will be. In all such
cases, the beliefs, pleasures, fears, and so on are said to be
"false" (*pseude*, *Phlb.*40c-e).



More importantly, there are several passages where Socrates discusses
falsehood in belief and speech at length, as a familiar and important
problem in need of resolution. In the *Cratylus*, Socrates says
that a great many people, both in the past and in the present, have
held that it is impossible to speak falsely, on the grounds that it is
impossible to say something without saying something *that is*;
Cratylus concludes that in such cases, instead of speaking falsely and
saying something that is not, the speaker would simply be making
noise, no more meaningful than banging a pot (429d-430a).
A similar
puzzle about false speech is posed in the *Euthydemus*,
initially by the brothers Euthydemus and Dionysodorus, a visiting tag
team of Sophists who are displaying their eristic prowess (283e-284e).
It is later
reprised by Socrates, who attributes it explicitly to
"Protagoras' followers" and still earlier thinkers,
and it is explicitly extended to false belief as well (286c-d).
These versions
of the puzzle frame it in terms of whether one can speak (or think) of
"what is not": one cannot speak without there being
something that one is saying (or thinking); yet it is impossible for
there to be such a thing and for it not to be. But that is what
speaking falsely would amount to, since on this view speaking falsely
just is to say something that is not. Plato never explicitly questions
the relational character of speaking and believing or rejects the
requirement that the relata must exist or obtain. In the inconsistent
triad we considered above, it is the third proposition,
"Sometimes we can think about what does not exist/obtain,"
which is consistently under pressure in these contexts. At the same
time, Socrates objects that such a position would be self-undermining
(*Euthyd.* 287e-288a),
though he does not offer a further diagnosis
here.



The puzzle about false belief recurs in the *Theaetetus* at a
crucial juncture in the dialogue's main argument. Socrates and
Theaetetus have rejected the proposal that knowledge is perception and
with it the underlying Protagorean view that whatever appears to be
the case is the case. Theaetetus' new proposal, that knowledge
is true belief, offers no advance, though, unless they can show that
false belief is possible, against sophistic puzzles like we have just
seen from the *Euthydemus*; and while Socrates says he has
"often" worried about this, he claims that he is unable to
say what false belief is and how it comes about (187b-e).
He then develops
the worry in much more elaborate ways than before. There is a fuller
version of the puzzle than we have seen so far, which explicitly
equates believing something "that is not" with not
believing anything at all (188d-189b).
But Socrates also introduces a distinct, new
psychological worry into consideration. If one assumes that false
belief by its very nature has a certain structure, namely, of
mistaking one thing for another, we must then ask what our cognitive
access is to each: do we know each of these, or only one, or neither?
(188a-c)
Socrates makes this underlying structure explicit when he goes on to
analyze false belief as a kind of "other-believing"
(*allodoxia*), where we say in thought that something is one
thing instead of another (189c-190e).
This analysis avoids the earlier difficulty,
since both items can be things that are, and it locates error in our
having latched on to the wrong one. From a third-person point of view,
this is illuminating, since it exposes precisely why the belief is
mistaken. But for just the same reason the description is unacceptable
from a first-person point of view for the subject who is taken in: no
one, Socrates insists, would ever say *to themselves* that
Socrates is Theaetetus or that one thing is something distinct from it
(190a-c). And in
fact Plato repeatedly characterizes thinking as saying something to
oneself, both in this dialogue (189e-190a)
and later in
the *Sophist* (263e-264a);
an analogous view also seems to be implicit in
the image from *Philebus*  38e-39a
of an internal
scribe writing out our beliefs in our soul. This treatment of
other-believing in the *Theaetetus* thus seems to presuppose
that both terms must be somehow present to thought in order for the
substitution to occur (190d). The possibility
that one might have only one of them in the mind, through perception
or in some other way, and somehow apply it to the wrong thing in the
world is not considered (even though it is something that Plato allows
in the case of incorrect names at *Cratylus* 430a-431b,
where he
speaks of pointing or otherwise exhibiting the thing while applying a
name to it).



At this point in the *Theaetetus*, Socrates proposes a model
for how false belief can occur, based on an analogy with how signet
rings can be impressed into a wax block to produce a sealing: in a
similar way, our thoughts and perceptions make an impression on our
memory, leaving behind traces which are signs or representations of
the original objects thought about or perceived (191c-d;
194c-d).
These traces can
then be deployed in combination with fresh perceptions of objects,
with which they may or may not accord, to produce beliefs. When one of
these traces does not "fit" an incoming perception, like a
shoe put on the wrong foot, the combination is incorrect and the
resulting belief false (193c-194b).
The model satisfies both constraints introduced
by the earlier puzzles: it provides cases of falsehood where we are
related exclusively to things that are, and where both items are in
some way present to thought. But as Socrates develops the suggestion,
it is made to rely crucially on our having different kinds of
cognitive access to the two items combined in the belief (memory
traces, on the one hand, and perceptions, on the other: 195c-d).
As such, it does
not serve to explain cases where just thoughts are involved, as when
someone incorrectly believes that the sum of 5 and 7 is 11 (195e-196a).
This is
enough to vitiate the account Socrates and Theaetetus have given of
false belief. But there should no longer be an issue about whether
false beliefs are *possible*, the challenge posed by the
original puzzles, only about whether we have been given a *fully
comprehensive* account. Socrates tries to salvage the theory by
proposing another model, where having different thoughts is compared
to grabbing at birds in an aviary (197c-200d).
Here again
the constraints introduced by the earlier puzzles are met, but the
account does not seem any more promising, if taken as a general theory
of false belief. It is soon given up after being subjected to a number
of objections, and Socrates returns to the dialogue's main
concern with knowledge. 



The *Theaetetus* does not have much to say about intentionality
more broadly, in particular about the intentionality of the
perceptions and thoughts that are combined in belief - the
dialogue's attention to these issues is limited, understandably,
by the exigencies of the main argument. Perception had earlier been
dismissed as not being in a position even to attain truth (186e),
much less being capable of falsehood; but little
is said about how perceptual content should be understood. The final
section of the dialogue briefly raises an important problem about the
intentionality of thought, however, which is entirely distinct from
the problems involving falsehood or nonexistence. If one has a true
belief about something, but not knowledge, and in particular does not
grasp how that thing differs from all other things, Socrates worries,
then how does the belief manage to be about the very thing it is in
fact about? How can thoughts of general characteristics, that are
shared equally by other things, "make me think of Theaetetus
rather than of Theodorus, or of the most distant Mysian, as the saying
goes?" (209b) This is an especially
clear statement (in all likelihood the first) of what Chisholm would
later call "the problem of objective reference." And his
reading of the *Theaetetus* may well be what lies behind
Wittgenstein's own statement of the puzzle: "What makes my
representation of him a representation of *him*? Not the
similarity of the image." (*Phil. Invest.*, II.177,
SSiii)



Plato offers a solution to the puzzles about falsehood in the
*Sophist*. It goes unchallenged in the text and may well have
been regarded by him as definitive. (It need not be a recent discovery
on Plato's part, as is often assumed; he needn't have been
stumped by these puzzles himself when he composed the earlier
passages: see Burnyeat 2002.) In this dialogue, when the Eleatic
visitor introduces the puzzles about false belief and speaking
falsely, he points out the danger of contradicting oneself, invoking
Parmenides' proscriptions against speaking of what is not
(236e-237c). But
he also insists that we must find a way of reconstruing such claims,
if we are to show that falsehood is possible (240d-241b)
without
committing patricide against "Father Parmenides" (241d).
The subsequent solution turns on recognizing a
complexity in the structure of statements, between the subject, which
is named in the statement, and what is said about it, as expressed by
the predicate (261d-262d).
Statements are no longer thought of on the model
of names, which are true if they name something "that is."
Instead, for a statement to be meaningful, one part of it must
successfully name something and the other say something about it,
which may be either true or false of this. Something analogous will
hold for belief, the visitor says, as belief is taken to be a kind of
internal assertion made by the soul (263d-264b).
As we have
seen, several features of this solution are already prefigured in the
*Theaetetus*: both the requirement that thought and speech be
related only to what is, and the insight that the complexity of
statements and beliefs allows for error to occur in a mismatch of the
parts or a misapplication of one to the other. But it is only in the
*Sophist* that this mismatch is explicitly characterized in
terms of the *difference* between things that are, rather than
simply being about "what is not." A false statement
asserts what is not the case regarding the subject, by stating that
the subject is *other* than it in fact is (263a-d).
The analysis in
the *Sophist* appears incomplete as it stands, though, since it
only applies to subject-predicate sentences, where the subject
succeeds in referring to something (262e,
263c): it is unclear how the visitor would
handle other types of statements, much less negative existentials
(such as 'there are no witches'). It also gives no account
of naming or nonpropositional attitudes. But, again, if we consider
only the original challenge posed by Parmenides and the Sophists,
namely, to show that falsehood is possible, then Plato has clearly
succeeded in providing an answer.


## 5. Aristotle



Medieval theories of intentionality - not to mention more recent
philosophers influenced by these theories, such as Brentano (1874
[1995]) - draw their inspiration from Aristotle's theory
of perception and thought, in particular his doctrine that in
cognition the form of the sensible or intelligible object is
"received without the matter" (*On the Soul* II 12,
424a17-24; III 2, 425b23-24; III 4, 429a15-19; and
III 8, 431b26-29) and the doctrine that the object, or more
precisely its activity as an object of cognition, is "one and
the same" as the activity of cognition and is present in the
cognizing subject (III 2, 425b25-426a27). Both perception and
thought are intentional states, and Aristotle's analyses of them
are central to his psychological theory as a whole. But none of these
passages gives clear evidence of Aristotle's awareness of the
*problem* of intentionality, much less provides a definition of
intentionality or any of its essential features. To begin with, each
doctrine applies to more than just intentional states. The impression
of signet ring in sealing wax is offered not merely as an analogy, but
as a genuine example of a form's being received without the
matter, a point accepted even by commentators such as John Philoponus
and Thomas Aquinas; Philoponus also mentions images in mirrors as
another example (Philoponus, *On Aristotle's* On the
Soul, 444.17-26, 437.19-25; Thomas Aquinas *On
Aristotle's* On the Soul 2.24, 56-59 = SS554). This
doctrine cannot therefore provide a sufficient condition for
intentionality, still less for cognition or awareness. Similarly,
Aristotle defends his claim that the object's activity is one and
the same as the activity of cognition and present in the cognizing
subject as simply an instance of a much wider causal generalization:
in every causal interaction, including inanimate and noncognitive
ones, the activity of the agent is one and the same as the activity of
the patient and occurs in the patient (*On the Soul* III 2,
426a2-11). Further, neither of these doctrines holds for all
intentional states: each fails to apply to paradigmatic cases of
intentionality, like dreams or future hopes, where the problem of
intentionality is most palpable. So neither doctrine provides a
necessary condition for intentionality either. They are rather general
causal doctrines that apply to a special class of intentional states,
like perception and thought, where the intentional state is about what
brings it about - that is, it is about its own cause -
something that is not true of intentional states in general. Even if
they prove to be central to his *theory* of intentionality,
they do not directly address the problem as such.



Aristotle is, however, keenly aware of the special character of
intentional states. In fact, he excoriates his predecessors for
failing to account for intentional states whose objects are
*not* the causes that bring them about. In the second chapter
of his essay *On Memory and Recollection*, he rejects the idea
that thought extends, like a ray, to its object, because we
"think in the same way even when they do not exist": in
such cases a ray will not work, since there won't be anything
for it to extend *to* (452b9-11). He goes further in his
polemic *On Ideas* (81.25-82.1), when he rejects Platonic
theories that take our thoughts to be of Platonic forms. Because such
objects supposedly always exist, whether or not the individuals that
fall under them do, this sort of theory evades the previous criticism:
given such intermediaries, there *is* something thought can
reach. But, Aristotle objects, they cannot account for the full range
of thoughts we actually have, since we can think of particular
individuals who no longer exist, like Socrates, and mythical creatures
that "do not exist in any way at all," like the
hippocentaur. In such cases, there is no Platonic form that can serve
as the object of thought: by the Platonists' own lights, there
is no form of Socrates or of Hippocentaur. So simply positing a
special object of the same type as a Form won't suffice. 



Aristotle seems confident that his own theory has the resources to
deal with both sets of counterexamples. He believes there are changes
in our bodies that *represent* or *model* the objects in
question (without being instances of the exact same type), and by
undergoing these changes we are able to have thoughts with the
relevant contents, whether or not the corresponding objects exist in
the world at large. He describes such changes as *phantasmata,*
a term often translated as 'images.' But while such
representations are underlie imagistic experiences, such as
visualization and dreams, they also bear content in the absence of
such experience. Aristotle deploys *phantasmata* throughout his
psychology, both in cognitive states, like thought and memory, and in
desires, passions, and action. The underlying capacity, which he calls
*phantasia,* is formally introduced in *On the Soul* III
3 in response once again to the problem of intentionality. According
to Aristotle, his predecessors are unable to explain how error could
ever take place. On their view, all cognition is about what brings it
about, such that "like is known by like," and this, he
believes, precludes the possibility of error (427a9-b6). But to
the extent Aristotle himself explains perception and thought along
similar lines, he will be vulnerable to the same criticism; and
consistent with this, he actually regards both states (at least in
their most basic forms, which we might call 'sensation'
and 'understanding') as incapable of falsehood. But unlike
his predecessors, Aristotle does not think that *all* mental
states are to be explained on this simple model. As he immediately
goes on to argue, *phantasia* is a distinct kind of mental
state that cannot be reduced to sensation, understanding, belief, or
even a combination of belief and perception (428a24-b9). It
consists in perceptual traces, which are capable of affecting the
central organ in the same way that perceptual stimulations do and so
capable of producing similar experiences even in the absence of the
corresponding external objects. It is this, he claims, that makes
falsehood possible and so explains the actions and reactions of
animals (428b10-429a8).



Thought, Aristotle insists, always requires a *phantasma*
(*On the Soul* III 7, 431a16-17, b2; III 8,
432a8-10; *On Memory* 1, 449b31). But the content of even
the simplest concept goes beyond that contained in any such
quasi-perceptual representations (*On the Soul* III 8,
432a12-14). At a minimum, in thought we are able to focus
selectively on certain features, by ignoring many of the other
features in such representations, just as we can use a diagram of a
triangle for mathematical purposes without being concerned with its
particular dimensions, and so effectively *abstract* them
(*On Memory* 1, 449b31-450a17). But we are also capable
of using one concept to form the opposite concept and of applying one
concept to another to result in a compound propositional thought
capable of truth or falsehood (*On the Soul* III 6;
*Metaphysics* VI 4, IX 10; *On Interpretation* 1). The
abstract content that results from such operations allows us to use
symbols to speak and understand one another (*On
Interpretation* 1, 16a3-9).



Aristotle also considers higher-order perception and thought. He
offers a regress argument at the beginning of *On the Soul* III
2 to show that when we perceive that we see or hear, we have a
higher-order perceptual awareness of the first-order perceiving
(425b12-25) and, while the precise details are a matter of
controversy, it is arguably the same act of perception being directed
at itself (Caston 2002*b*; for a response, see Johansen 2005).
But Aristotle elsewhere claims that in general states like knowledge,
perception, belief, or thought are always directed at *something
else* primarily and themselves only peripherally or "on the
side" (*en parergoi*); only God's
self-reflexive thinking, which he characterizes as a "thinking
of thinking" (*noesis noeseos*), has
itself as its primary object (*Metaph.* XII 9,
1074b34-36). Self-directed intentionality raises a number of
questions, in particular whether Aristotle is committed to it being a
part of *every* mental act - as he seems to claim at
*Nicomachean Ethics* IX 9, 1170a29-b1, which Brentano
1874 [1995], Book II, chs 2-4 takes up and champions - and
whether he thinks it is possible to be in error about the content or
character of the first-order state, even if not about its existence
(Caston 2002*b*).


## 6. The Stoics



The earliest Stoics seem committed to preserving the intuition that
whenever we are in a mental state, *there is something* that
our mental state is of or about. But they reject the Parmenidean
requirement that this must be something "that is",
something that exists or obtains. On the contrary, they claim that
"in the nature of things, some things are and some are
not," since the nature of things includes "anything that
comes to mind, such as centaurs, giants or anything else made up by a
false thought." (Seneca *Letter* 58.15) Accordingly,
these Stoics regard *Something* as the highest genus, rather
than *What is* or *What has being*, as Plato had.
Whenever a *phantasia* or representation is of something which
does not in fact exist, there still is something our representation is
of, which they call a *phantasma*, an "apparition"
or "figment". Even though it does not exist, on this view
it is still something and so can serve as the object of our mental
state.



This position does not seem to have to have arisen from idle
speculation, but rather as part of a response to Plato. The first two
heads of the school, Zeno of Citium and Cleanthes of Assos, argue that
there are no such things as Plato's forms. The concept
(*ennoia*) of a kind, that is, of a genus or species, is a
thought of what they call an *ennoema*, an object that is
quite literally "in a thought" (*en* +
*noema*), an "immanent object", but is found
*only* in thought. The precise nature of these objects is
controversial. According to one source (Stobaeus, 1.136.21 ff.), they
are "*not* something" and so not something
qualified in a certain way, but only "as if" they were
something and "as if" they were qualified; they are
further said to be only "apparitions" or
*phantasmata*, something merely represented. On this basis,
most interpretations take the Stoics to hold that the objects of these
thoughts are "not-somethings" (*outina*): fictions
or figments that are so beyond the pale, allegedly, that they do not
even count *as something*. But so understood, the Stoic view
would be deeply obscure, if not actually incoherent. If the objects of
these thoughts are not something, they are not anything, on pain of
contradiction. That, after all, was the point of claiming that
*Something* is the highest or most comprehensive genus:
*everything* is something. But if there are no such things,
then what is gained by replacing Platonic forms with
*ennoemata*, rather than simply eliminating Platonic forms
altogether? Worse, what becomes of the intuition that whenever we have
a representation, there *is* something that our representation
is of?



The earliest Stoics do think they have gained something by this move,
though. They appeal, unsurprisingly, to both genera and species in
characterizing the methods of definition and division, which they take
to be central to logic and reasoning. Far from being a blank nothing,
these objects are distinguished from one another in terms of their
common features and differences, as they would have to be for the
classificatory system required for dialectic and science. The Stoics,
moreover, explicitly *quantify* over these objects: there is,
in fact, a distinct object of thought for each number (Plotinus
*Enneads* 6.6.12.13-29). In referring to them as
"apparitions" (*phantasmata*), moreover, the Stoics
are not eliminating them. They are recognizing them as something that
our mind is directed towards whenever something general
"appears" to us or is represented (*phantasia*).
For as we have seen, they hold that whatever appears to us *is
something*, even if it is not something that exists or obtains.
The natural move for the Stoics, then, would be to say that while
Platonic forms aren't anything at all - there are
*no* such things - there *are* such things as
*ennoemata*; they just aren't anything that
*is*, that exists or obtains. And in fact a parallel report in
Diogenes Laertius can be read in precisely this way: although an
*ennoema* is not anything *that exists* and so does
not possess qualities, it is nevertheless "as if" it were
something *that exists* and "as if" it possessed
qualities, "like the impression of a horse when none is
present" (Diogenes Laertius VII 61). In such a case, what I
imagine is something and indeed something horse-like; but it is
not a real horse or anything existent, and so on their view not
something that can act or be acted upon and so not a body. It is
merely an object of thought.



Such generic objects will further be incomplete or indeterminate. It
will not be true to say that the generic human (*genikos
anthropos*) is Greek, for example, or equally to say that it
is not Greek, even in an "as if" sort of way, since some,
but not all, humans are Greek (Sextus Empiricus, *Adv. math.*
VII 246). A generic object will be "as if" it were
*F* if, and only if, *all* the individuals falling under
it are *F*. This claim need not violate the Principle of the
Excluded Middle, since it would still be true of the generic human
that it is *either* Greek *or* not Greek, since it is
true that all humans are either Greek or not Greek. But it would
violate the Principle of Bivalence, since it still will be neither
true nor false to say that the generic human is Greek. (For further
discussion of *ennoemata*, see Caston 1999.)



The third head of the school, Chrysippus of Soli, avoids these
problems by appealing instead to "that which can be said"
or "meant" (*lekta*, lit. 'sayables'),
certain abstract objects that are signified by our words.
*Lekta*, like place, void, and time, cannot themselves either
act or be acted upon, and so in the Stoics' view cannot be
bodies, which are the only existents they recognize; all such entities
are instead classified as "incorporeals"
(*asomata*). But *lekta* will still be
*something*, since in each case there is something that our
words signify; it is just that they "subsist"
(*huphestanai*) rather than exist (*einai*), as the
Stoics sometimes say. Unlike *ennoemata*, however, they
will not generally be the *objects* of mental states (except
perhaps when we are thinking about Stoic semantics, for example). They
serve rather as the *contents* of mental states, which can be
articulated in language, regardless of which objects (if any) these
states are directed towards (Sextus Empiricus *Adv. math.* VIII
11-12, 70, 409; Diogenes Laertius VII 63). There are
*lekta* corresponding to general terms and predicates, as well
as to sentences of all kinds: not only to simple and molecular
propositions (*axiomata*), but also questions, commands,
oaths, suggestions, prayers, and so on (Sextus Empiricus *Adv.
math.* VIII 71-73; Diogenes Laertius VII 66-8). For
Chrysippus, moreover, a definition like 'a human is a rational
mortal animal', should not be construed as being about a generic
object, even in an "as if" sort of way. Rather it has the
same meaning as the universal generalization, 'if something is a
human, then that thing is a rational mortal animal' (Sextus
Empiricus *Adv. math.* XI 8-11). But such a proposition
commits us to nothing more than the relevant *individuals* that
satisfy it (if indeed there are any) and to the *lekta*
signified by its predicates. Finally, unlike generic objects,
*lekta* are not indeterminate. It is simply *false* to
claim that what is expressed by the predicate 'is a human'
is itself a human (and likewise simply true that the predicate
'is a predicate' is itself a predicate). Therefore,
*lekta* need not pose a threat to the Principle of
Bivalence.



One of the most tantalizing questions concerns the relationship
between mental representations (*phantasiai*) and
*lekta*. The Stoics effectively endorse a version of
Brentano's Thesis that intentionality is the criterion of the
mental, which demarcates the domain of psychology. The Stoics think
that representations are what set animals and humans apart from plants
and inanimate substances: only things with *psuche* or
soul have mental representations (*phantasiai*) of the world
and make efforts (*hormai*) to move and change things (Origen
*On Principles* 3.1.2, 196.12-197.8 Koetschau). But they also
think that representations are a pervasive feature of psychological
phenomena: every mental state either is a representation or involves
one essentially, because it is an assent to a representation as
correct or rejection of it as incorrect or withholding assent from it
altogether. So representation (*phantasia*) is a feature of all
and only mental states. *Lekta* constitute the content of these
representations. The Stoics in fact define them as "what subsists in
correspondence with a rational representation," where a rational
representation is one that belongs to rational animals like ourselves
(Diogenes Laertius VII 63; Sextus Empiricus *Adv. math.* VII
51).



This definition, though, also poses a difficulty. In recent decades,
it has been thought to imply that *lekta* subsist *only*
in connection with the representations of rational animals -
something not stated explicitly in our reports - even though
this would have problematic consequences: it would imply that
nonrational animals and indeed very young humans, before they develop
reason, would either paradoxically have representations without any
content at all or solely with nonconceptual content that could not be
articulated. (For a classic statement of the view, see Frede 1983
[1987], 153-54, 156; for a discussion of the consequences, see
Sorabji 1993, 20-28.) Neither the Stoics nor their critics ever
mention such consequences, and it would make it difficult, if not
impossible, for them to account for animal behavior, much less the
emergence of reason itself in humans. They insist that we have no
concepts (*ennoiai*) at birth, comparing the mind to a blank
sheet of papyrus, ready to be written upon: it is first inscribed by
perceptions and then subsequently, through the sorting and collection
of perceptual memories, by experience, issuing in our first natural
concepts, from which we can later construct even more complex
concepts. Reason only appears later - some sources say at age
seven, others at fourteen - when there are sufficient concepts
to form a stable, interrelated system (Aetius 4.11.1-4; Plutarch
*On Common Conceptions* 1084f-1085a;
Diogenes
Laertius VII 53). So on the Stoics' view, children will possess
concepts at some stage *before* they have reason, since reason
emerges from the cumulative acquisition and systematization of
concepts, and evidently some of these concepts are formed naturally
from perceptions and memories alone, unaided by reason, from which
they presumably derive their content at least in part. Since all these
states undoubtedly possess content, there is no principled ground for
denying analogous content in the case of representations in
nonrational animals either, at least for perceptual
representations.



If *lekta* serve here, as elsewhere, as the content of these
states, then *lekta* will not correspond *solely* to
rational representations. But how, one might reasonably ask, can the
represenations in nonrational animals and very young humans, who are
without concepts and incapable of articulate speech, have
*lekta* corresponding to them? There is a widespread assumption
in the secondary literature that whether a *lekton* corresponds
to a representation depends upon which concepts (if any) an individual
possesses. But the Stoics cannot accept this assumption. Quite the
contrary. They believe that a *lekton* is involved in
*every* causal interaction, whether animate or inanimate: one
body causes a *lekton* to become true or hold of another body,
where the *lekton* specifies the fully determinate effect of
the agent on the patient (Stobaeus 1.138.14; Sextus Empiricus *Adv.
math.* 9.211; Clement of Alexandria *Stromata*
8.9.3-4; this point is rightly emphasized by Frede 1994). But
this analysis of causation immediately becomes pertinent once we
acknowledge that the Stoics also hold a causal theory of
representation: they define representations as the effect -
literally, an "impression" (*tuposis*) -
that in the paradigmatic case the object of representation produces on
the soul (which on their view is a body); and they expressly compare
this to the impression a signet ring makes in wax (Diogenes Laertius
VII 50; Aetius 4.12.1-4; Plutarch *On Common Conceptions*
1084f-1085a),
and they appeal to sigillary language again when they define the
"secure" representation they regard as the criterion of
truth and foundation of knowledge (*phantasia
kataleptike*), which represents the object that produces
it in such rich detail that it could be distinguished from anything
else, no matter how similar (Cicero *Acad.* 2.77-78; Sextus
Empiricus *Adv. math.* 7.248 ff.; Diogenes Laertius VII
46).



Whenever an object produces a representation, then, there will be a
corresponding *lekton* that specifies the object's fully
determinate effect on the soul: not only that it is a representation
and a representation of a certain sort, but one that represents
objects in the world as having various features and standing in
various relations, potentially in extraordinarily rich detail.
Embedded within this complex *lekton* will be a clause that
exhaustively expresses the content: if all such *lekta* can be
captured with the schema, '... forms a representation
*that* -', whatever fills the second blank will express
the total content of the representation. None of this requires concept
possession or even conceptual abilities: which *lekton* belongs
to a representation is determined causally by the interaction of a
specific object and a specific subject in certain conditions, so long
as the subject is capable of forming a representation when affected by
appropriate objects in the right way. Perceptual representations even
in nonrational animals will ordinarily have tremendously detailed
contents, which cannot be exhaustively expressed by a simple
proposition, as part of the corresponding *lekton*. Humans can
go further than nonrational animals, though, through their ability to
focus selectively on individual parts of such content and respond
differentially, assenting to some, rejecting others, and withholding
assent on still others. This ability to consider isolated contents is
what allows rational animals to entertain abstract representations,
whose total content *can* be expressed by a simple proposition;
or indeed to entertain any content formed by logical operations upon
these (possibly recursively). It is therefore only by reference to the
contents of rational representations that we are able to capture the
full domain of *lekta*, much as the definition in Diogenes
Laertius and Sextus Empiricus suggests, so as to include abstract as
well as perceptual representations. But this does not exclude
nonrational animals from also having *lekta* corresponding to
their representations, thus making intentional explanations of their
behavior possible and psychology more generally. (For more on Stoic
representations and a fuller defense of the interpretation above, see
Caston *forthcoming*.)