## 1. Historical contributions



The history of process philosophy extends far into antiquity, both in
Eastern and Western thought. In the Western tradition it is the Greek
theoretician Heraclitus of Ephesus (born ca. 560 B.C.E.) who is
commonly recognized as the founder of the process approach. The few
remaining fragments of Heraclitus' doctrine are often
interpreted as championing a philosophy of ubiquitous and radical
flux, epitomized in the slogan *panta rhei* ("everything
flows"). But Heraclitus' claims are more sophisticated. To
be sure, the fragments contain an unambiguous commitment to ubiquitous
dynamicity: "this world-order ... is ... an ever
living fire..." (Fr. 217, Kirk-Raven-Schofield). Whatever
exists is a transformation of this cosmic fire, turning into
apparently stable forms of matter such as sea and earth (Fr. 218), but
all the while remaining present in these apparent stabilities (Fr.
204). Cosmic fire is the source of change of all observable
cosmological and natural processes. Moreover, Heraclitus also
postulates that all observable changes result from a
"strife" of opposing forces to overcome each other, thus
creating transformative power as the ruling condition of existence:
"war is the father of all and king of all" (Fr. 212).
However, Heraclitus' reputation as the great proponent of
*radical* flux (alteration at every instant) may be mainly due
to the influence of his early commentators: Plato, Aristotle,
Melissus, and Theophrastus. For one must not overlook that in the
fragments we have from Heraclitus, dynamicity is tied inextricably to
balance or "measure" (Kirk 1951). While fire is postulated
as an underlying pervasive cosmic factor that is creative and
self-moving, the changes produced by fire happen in a regulated,
measured way. Fire is "kindling in measures and going out in
measures" (Fr. 217) and "all things are an equal exchange
for fire and fire for all things, as goods are for gold and gold for
goods" (Fr. 219). Furthermore the opposing forces, which are
manifestations of fire, form unities of cyclical
alternation--"day night, winter summer, war peace, satiety
hunger unity"(Fr. 204)--that proceed within the limits of a
quantitative measure (*metron*) reinforced by a
"law" of nature (Fr. 226). The unity of opposites thus
creates an overall balance of reciprocity by cyclical transitions
between extremes--"these things change places and are
those, and those change places again and are these" (Fr.202).
The "same rivers" are constituted by the regular flow
patterns of "different and different waters" which
"scatter and...gather...come together and flow
away...approach and depart" (Fr. 214). Moreover, the unity
of opposites also produces the dynamic arrest we know from "the
bow or the lyre" (Fr. 209), i.e., the motionless dynamic
presence resulting from the tension of a 'backstretched
connection' (*palintonos harmonie*) pulling equally
into two opposite directions. In short, Heraclitus articulated three
fundamental insights that became seminal in the history of Western
process philosophy, despite the somewhat tendentious portrait of his
thought in Greek antiquity. First, Heraclitus assigned to process or
dynamicity the role of an explanatory feature, not only of a feature
of nature to be explained. Second, he suggested that processes form
organizational units and occur in a quantitatively measurable and
ordered fashion. Third, he contrasted dynamic transitions or
alterations with dynamic permanence, and thus for the first time
identifies, and differentiates between, two basic
'Gestalts' or forms of dynamicity.



The direct counter-model to Heraclitus' explanation of natural
changes was the atomism of Leucippus, Democritus, and Epicurus, who
viewed matter as constituted by inert material atoms with permanent
properties (e.g., weight) and took natural developments to be the
macroscopic effects of atoms colliding and changing their spatial
positions. Aristotle complained that the source of motion for these
collisions remained unexplained and developed a philosophy of nature
that includes a coherent account of the source of motion in natural
occurrences, allowing also for explanations in terms of self-realizing
and self-maintaining structural or formal factors. In
Aristotle's view an item in nature persists by the active
exercise of a collection of capacities, a self-maintaining internal
process organization (*physis*, or more generally
*morphe*) that realizes a characteristic sort of
functioning; by means of these characteristic types of functioning we
sort entities into natural kinds. These kind-specific capacities must
be realized within a matter or medium (*hyle*) that
supports the relevant process organizations but that also harbors
counteracting, disintegrative tendencies, due to the fact that the
elemental components of matter (fire, water, earth, or air) actively
strive towards their "natural place" further up or down.
If Aristotle indeed took these active elemental tendencies as
fundamental and allowed for elemental transformations as changes
*per se* without an underlying substratum or prime matter (as
argued in Gill 1989), he can be counted as a process philosopher. But
Aristotle also supplied in his characterization of substance
(*ousia*) those aspects that subsequent history selected to
form the basic tenets of the paradigm of 'substance
metaphysics.' In addition, substance-metaphysics could also draw
on Aristotle's classification of changes (*kineseis*)
into generation, destruction, alteration, and locomotion, since this
classification rests on a sophisticated doctrine of
"potential" vs. "actual" features that are all
attributed to a static subject of change. Aristotle's
distinction between *kinesis* (in this context: change,
transition towards a goal) and *energeia* (in this context:
activity), on the other hand, must again be counted as an important
contribution to process thought. Aristotle's distinction is
formulated in relation to agentively initiated changes and activities,
but the logical distinction arguably extends beyond actions to
occurrences in general. *Changes* such as *building a
house* or *learning* lead to an end (*telos*) that
lies "beyond," and are incomplete as long as the end is
not reached--"someone who is building a house, has not
built it" (Metaphysics Theta 6). In contrast,
*activities* such as *seeing* or *living well*
are ends in themselves and complete at any moment for as long as they
last--"he who is seeing has seen." Aristotle's
distinction between changes and activities is significant in its own
right, but even more seminal for present-day process philosophy, since
it is the first attempt to classify types of occurrences in terms of
logical and linguistic features of associated expressions (see section
3 below).



The history of Western metaphysics since Aristotle was mainly focused
on elaborating various versions of substance metaphysics--in
fact, as one might say with Hegel, "the history of [Western]
metaphysics is the tendency towards substance." However,
interspersed in this history of substance metaphysics are pockets of
process thought, partly as supplementary elements to an otherwise
substance-geared theory, and partly as independent
process-philosophical explorations. For example, the neo-Platonic
philosopher Plotinus (204-270) introduced the thought that the
dynamicity of being is the "emanation of the divine."
Thomas Aquinas (1225-1274), Aristotle's most famous commentator
in the middle ages, kept some of the processual aspects of
Aristotle's scheme more clearly in view than later scholastics.
Renaissance philosopher Francesco Patrizi (1529-1597) offered
mereological descriptions of the diffusion of processes in order to
develop a "metaphysics of light." G. W. Leibniz
(1646-1716) devised a fully-fledged process-based metaphysics,
postulating as basic individuals so-called "monads."
Monads are ordered sequences of states of affairs consisting of the
co-exemplification of properties during some period of time. But
monads are not static: they are endowed with an inherent "active
force" that engenders the transitions between states. Moreover,
since Leibniz took temporal relations to be "founded" in
the properties of monads, states of monads are *per se* not
temporally
 discrete.[1]



A special branch of process thought opened up in late 18th and early
19th century German Idealism, when Johann G. Fichte, Friedrich W. J.
Schelling, and Georg W. F. Hegel responded to Immanuel Kant's
system of a transcendental idealism. All three of these thinkers
alerted to the processual nature of the "transcendental
subject," and aimed to overcome Kant's incongruous
postulate of unknowable "things in themselves" by focusing
on the process by which the world of knowable appearances, including
reflective reasoning, is generated--this process, or so the
argument goes, is the most promising candidate for reality in itself.
Hegel provided the most comprehensive and detailed elaboration of this
basic idea. He postulated that reality is the self-unfolding of
dynamic structures or templates ("Begriffe"); among these
templates external contrasts arise, which trigger self-modifications
of the templates into more differentiated versions; these in turn
create further external contrasts. The result is an increasingly
interrelated web of dynamic dependencies, and the "movement of
reflection" that drives the interrelated differentiations of the
templates in the end reaches a dynamic fixed point. According to
Hegel's dynamic structuralism, self-unfolding reality
differentiates itself into mental, natural, socio-cultural, and
institutional processes, and, in fact, over time develops any possible
differentiation, so that in the end reality occurs as the totality of
all possible forms of mutual conditioning. Hegel argued that this
overall "movement" of gradual self-determination by
internal and external differentiation drives all actual and possible
developments according to its inner necessity--reality is
"reason" articulating itself as and within the world.
Hegel called this movement "dialectics" and his
philosophical system was an attempt to work out the
'logic' underlying the total dialectical development of
reality. Schelling claimed that Hegelian dialectics provides, at best,
a description of the development of constraining conditions on
reality's self-unfolding. But, Schelling argued, the productive
dynamicity of the process that is being constrained is neither
included nor explained in Hegel's system, and correctly so,
since the latter is necessarily transcendent to conscious human
thought. From the perspective of contemporary process ontology, the
development of German Idealism between 1790 and 1850 in the debate
between Fichte, Hegel, and Schelling displays in instructive ways the
limitations of a process metaphysics that puts the occurrence type of
*productions* center-stage and, in particular, understands
cognition as a production: as a development with a product or result.
As pictures are the products of paintings, mental representations
(thoughts, concepts) were taken to be the quasi-objects that result
from the productive developmental occurrences of perceiving and
thinking. When we conceive of an occurrence as a production, we
separate conceptually between the product and the process generating
the product. Thus, productions are precisely the type of occurrences
that prevent us from conceiving the dynamic presence of reality in
itself as "process and result rolled into one," as Hegel
envisaged. The metaphilosophical debate between Fichte, Hegel, and
Schelling, which deeply influenced the further development of
'continental' philosophy from Nietzsche to Heidegger to
Derrida and onwards, can be viewed as ensuing from the assumption that
cognitions are productions of sorts--if cognitions had been
assigned another occurrence type, this specific metaphilosophical
debate could not have got off the ground.



Hegel assumed that the process of reality follows certain principles
that can be fathomed by philosophical inquiry. This thesis is the
hallmark of *speculative* process metaphysics, which has a
number of adherents also among later process philosophers but has been
championed most explicitly by Alfred N.
 Whitehead
 in his "philosophy of organism," worked out during the
early decades of the 20th century. The basic unit of reality in
Whitehead's system is an event-like entity called "actual
occasion," which is the procedural integration or
"concrescence" of processes of data transfer
("prehensions") into unities that become new data. Each
actual occasion is the growing together of the total available
information of the universe at that time, according to certain
principles, repeating and reinforcing certain patterns ("eternal
objects") and thereby creating new ones. Whitehead's
process metaphysics is arguably the most comprehensive descriptive
metaphysical framework we have to date--as Whitehead's
followers, past and present, have shown, not only can it be used for
the interpretation of familiar domains of philosophical concern, but
it can also provide illuminating descriptions for scientific domains
where other metaphysical theories have little to offer, such as
discourse pragmatics in linguistic typology, the neuro-psychological
foundations of value judgments, quantum physics, or measurements in
 astrophysics.[2]
 By refurbishing Plotinus's idea of divinity coming about in the
world's becoming, Whitehead's philosophy also provided a
new impetus to the philosophy of religion.
 Charles Hartshorne,
 perhaps the most eminent American philosopher of religion of the
Twentieth century, adopted and expanded Whitehead's ideas for a
process view of God and developed the position of
 process theism
 in the style of rational speculative process thought. It is important
to note, however, that while the early followers of Whitehead such as
Hartshorne and Paul Weiss embraced the speculative principles of his
philosophy, many present-day Whiteheadians are content to put the
system's ontological concepts to descriptive use.



Other proponents of speculative process metaphysics between 1850 and
1950, such as Charles S. Peirce, Samuel Alexander, C. Lloyd Morgan,
and Andrew Paul Ushenko, contributed two new motives for process
thought, namely, the philosophical explanation of evolutionary
processes and the philosophical explanation of emergence and
self-organization. However, they also created an image of process
metaphysics that in the eyes of their contemporaries appeared
methodologically problematic. The first step of these
process-philosophical enterprises seemed legitimate
business--surely it was important to identify the limitations of
mechanistic explanations in science. But it was the second step, the
endeavor of drafting purely speculative explanations for the direction
and the origin of emergent evolution, that went against the positivist
temper of the time. Such explanations did not sit well with the
philosophers who defined and shaped the "analytic" method
in postwar Anglo-American philosophy. As they rejected any empirical
claims that would go beyond what was scientifically proven, and
assigned to philosophy the more mundane task of analyzing conceptual
contents (as well as linguistic and social practices, and phenomenal
experiences), they increased the intersubjective verifiability of
philosophical claims. But in the course of this important
methodological revision the ontological categories of process
metaphysics were mostly thrown out wholesale with the bathwater of the
speculative explanations these categories were embedded in.



Nevertheless, twentieth century *speculative* process
metaphysics is paralleled by an *analytic-interpretive* strand
in contemporary process thought. This variety of process thought also
proceeds from the theoretical intuition that processuality, in its
various modes, is the primary starting point for a philosophical
description of the world or of reality, but does not speculate about
how reality develops. Here processuality either is a defining trait of
the basic categories postulated for the analysis of common sense and
scientific reasoning, in the style of analytic philosophy; or
processuality is conveyed in the network of metaphors selected for the
interpretation of human experience and the conditions of human
existence, in the style of so-called 'continental'
philosophy. Often contributions to analytic-interpretive processism
are also placed somewhere in the middle between the poles of analytic
versus continental methods in contemporary philosophy. The following
examples will illustrate this methodological openness of
non-speculative contemporary process philosophy.



Based on their analyses of phenomenal experience, the investigations
of the "reflex arc" that were coming out of the psychology
laboratory, and an analysis of human social praxis, William James and
John Dewey each developed contributions to a process-based pragmatist
metaphysics. James' process-based account of the self loomed
less large for the history of process philosophy, until recently at
least, than Dewey's more comprehensive view. Dewey holds that
all existents are events whose characters we determine by giving them
meaning in our interaction. For Dewey meanings are not abstract or
psychic objects but aspects of human cooperative behavior--in our
interactions with the world we create significances and thus determine
what kind of situation occurs. Working from studies of social
interaction, George Herbert Mead added to process-based pragmatism the
thesis that mind emerges from social communicative actions. On the
side of 'continental' philosophy, Henri Bergson arrived at
a process metaphysics again based on an investigation of phenomenal
experience, like James and Dewey. But while Dewey and other
pragmatists put the process-character of being partly into the hand of
human agents and their practical and theoretical interpretations of an
ongoing situation, Bergson argued that the process-character of being
is precisely out of our cognitive reach, at least in so far as we try
to conceptualize what we experience. As long as we understand
conscious experience as a subject-object relation, Bergson pointed
out, we merely follow the theoretical habits in which we have been
conditioned by the substance-metaphysical tradition. However, when we
carefully attend to what we take in during conscious experience,
especially our self-experience, without forcing a conceptualization of
that experiential content or the act of experience, we find not a
relation and ready-made relata but an interactivity--an ongoing
interfacing out of which world and self arise in our
conceptualizations. In immediate, non-conceptualized experience we
grasp the dynamicity of this interfacing as becoming or the flow of
duration ("duree"), but this felt dynamic content
of our experience transcends what we can conceptually articulate. As
soon as we try to conceptualize what we have grasped in
"intuition" we turn the continuous complex flow of
experience into a sequence of discrete units, into pluralities of
states of objects at locations that engender Zeno's paradoxes of
motion, and we transform our entangled being with the world into the
ever puzzling opposition of a subject and an object.



Martin Heidegger's early and late philosophy also presents an
analytic-interpretive contribution to process philosophy, without
speculative formulations of metaphysical 'laws of
development,' but with a view to the metaphilosophical and
practical implications of process metaphysics. In *Sein und
Zeit* (1927) Heidegger presents what could be called an
'adverbial model' of process metaphysics; based on an
analysis of human existence ("Dasein") Heidegger shows
that what the metaphysical tradition understood as entities or factors
standing in relational constellations--e.g., space, world, self,
others, possibility, matter, function, meaning, time--can be
viewed as 'adverbial modifications' of Dasein, as modes
and ways in which Dasein occurs, while Dasein itself is the
interactivity of "disclosure" or 'taking as.'
Since Heidegger's 'taking as' is an understanding
that is ineradicably practical, his early philosophy bears certain
affinities to the pragmatist tendency in twentieth century American
process thought. In Heidegger's later work, however, human
understanding is no longer the dynamic 'locus' but more a
dimension of the process of being ("clearing").



While many twentieth century American process thinkers were influenced
by Whitehead, some turned elsewhere or went their own ways. For
example, W. H. Sheldon championed a largely dialectical view of the
dynamic nature of reality with process as a principle of conflict
resolution. Wilfrid Sellars, one of the great figures in post-war
analytical philosophy, worked out what appears to be the first
consistently nominalist and naturalist system ever developed in the
history of Western philosophy; this is often overlooked, however,
since the system relies on a process ontology that Sellars only
briefly sketched but never elaborated. Naturalism implies a nominalist
account of properties, Sellars argued, which in turn can only succeed
if we take qualia to be aspects of processes--by categorizing
*blue* as *sensing-blue-ly*, we can make better sense of
how physical processes engender sensory contents (Sellars 1981). With
the envisaged process-based solution to the body-sensory problem,
which in many ways anticipates current ideas of "embodied
cognition," Sellars could further suggest a new process-based
re-interpretation of intentionality. Any kind of content, Sellars
argued, from the lowliest sensory content in bacteria to the
norm-governed contents of conceptual experience to the contents of
scientific theories, is nothing else but a way of
*functioning*. Taking over from Sellars the idea that content
is function, present-day functionalist theories of mind and cognition
typically fail to acknowledge Sellars and thereby miss the decisive
element for a successful functionalist 'reduction' of
intentionality and the mental, namely, that the reductive basis,
functions, are not static input-output tables but ongoing processes in
natural systems that realize, in this ongoingness, normative
socio-cultural practices (Seibt 2016). Recently American process
metaphysics gained another important voice in Nicholas Rescher who,
like Sellars, consistently pursued a systematic approach in
philosophy. Rescher made important contributions to *all*
philosophical disciplines; originally these were framed as components
of a system of "methodological pragmatism" and
"pragmatic idealism". In the mid-1990s, however, Rescher
sketched a process metaphysical embedding for his system, using
familiar philosophical terminology, and thus presented the first
systematic overview of the explanatory potential of a non-Whiteheadian
process metaphysics that forfeits technical expenditure and operates
with a notion of process that is close to our common-sense
understanding of developments. In parallel, since the past four
decades and with increasing intensity, researchers working in the
intersection of ontology and linguistics, in philosophy of mind and
cognitive science, in philosophy of biology or of quantum physics,
have addressed specific questions in these areas with greater
attention to types of processes and processual structures. These more
targeted investigations will be taken up below.



Generally speaking, current Western process philosophy has abandoned
all speculative aspirations and develops the descriptive,
analytic-interpretive strand of process thought (the exception might
be the use of process metaphysics in areas of philosophy of physics
where physics itself is speculative, see
 footnote 19).
 While interest in processism most recently has increased in analytic
philosophy of science, of mind, and of action, process thought is
currently also used to highlight productive affinities between the
continental and analytical trajectories of twentieth century
metaphilosophical *criticism* of traditional metaphysics. Such
analytic-continental cross-overs enabled by attention to process can
also be observed in philosophy of cognition and in the philosophy of
technology, often combined with alignments with the "4E paradigm
of cognition" or "post-phenomenology", respectively.
Another more encompassing exploration across borders, a detailed
historical and systematic comparison between Western and Eastern
process philosophy (e.g.,
 Daoism)
 is an important task yet to be undertaken.


## 2. Three tasks of process philosophy



As may have become clear from the brief review of historical
contributions to (Western) process philosophy in section 1, process
philosophy is a complex and highly diversified field that is not tied
to any school, method, position, or even paradigmatic notion of
process. Some process philosophers (e.g. Whitehead) took organismic
processes as their central model for a concept of occurrences that
generate the internal and external coherence of an entity. Others
(e.g. James) chose as their canonical illustrations individual
psychological processes, or (e.g. Alexander) took evolutionary
development as paradigmatic. Some process philosophers (e.g. Whitehead
and Morgan) articulated their approach in the form of an axiomatic
theory and in close relation to science, while others (e.g. Bergson)
worked from an almost mystical sort of sympathetic apprehension of
reality and insisted that process metaphysics could, if at all, only
be expressed by means of a highly metaphorical use of language. Some
processists (e.g., Roger Boscovich) championed a materialist position,
while others endorsed idealism (e.g., Leibniz and Hegel). The
historical overview in the preceding section also displays that the
tools of process philosophy are not tied to any specific method of
philosophical inquiry, giving present-day process philosophers a broad
spectrum of approaches with which to build their theories: by
conceptual analysis (via informal and formal reconstructions of
conceptual contents); by the integrative interpretation of scientific
results; or by phenomenological investigations. Similarly, while
compatibility with recent results of science is for many process
philosophers a privileged methodological constraint, others take
science to be merely an aspect of the more comprehensive philosophical
datum of cultural praxis.



In short, process philosophy is best understood as the effort to
replace a longstanding philosophical *research paradigm*, in a
sense close to T. Kuhn's use of the term, i.e., to replace a set
of longstanding fundamental assumptions that delimit the scope of
legitimate topics and direct theory construction. For example, process
philosophers assume that the only primary or basic ontological
categories should be terms for *occurring* entities, and that
certain formal theories--for example, set theory--are
ill-suited of themselves, without modifications, to express the
dynamic relationships among occurrences. Or again, process thinkers
hold that philosophical research may legitimately address
'creative' phenomena that cannot be described as the
modification of a pre-existing and persistent unit, such as phenomena
of complexity or self-organization. What unifies contemporary
process-philosophical research more than any other aspect, however, is
its metaphilosophical aim to revise long-standing theoretical habits.
Given its current role as a rival to the dominant substance-geared
paradigm of Western metaphysics, process philosophy has the
overarching task of establishing the following three claims:


* *Claim 1:* The basic assumptions of the 'substance
paradigm' (i.e., a metaphysics based on static entities such as
substances, objects, states of affairs, or instantaneous stages) are
dispensable theoretical presuppositions rather than laws of
thought.
* *Claim 2:* Process-based theories perform just as well or
better than substance-based theories in application to the familiar
philosophical topics identified within the substance paradigm.
* *Claim 3:* There are other important philosophical topics
that can *only* be addressed within a process metaphysics.



Contributions to current process-philosophical research typically
focus on (aspects of) only one of these three components of a theory
 revision.[3]
 More often than not, however, the larger purpose of the contribution
remains implicit, which is one of the reasons why contemporary process
philosophy, especially non-Whiteheadian process thought, does not
clearly stand out as a unified effort at theory revision. Process
philosophy currently presents itself as an internally diversified,
geographically and disciplinarily distributed phenomenon of innovative
thought in Western philosophy. Accordingly, there are significant
differences in how process philosophers approach claims (1)-(3).
In the following the focus will be on arguments for claims
(1)-(3) within contemporary analytical process philosophy. The
reader should thus keep in mind that the pointers set in the following
sections are partially representative at best and need to be
supplemented by introductions to, e.g., contemporary
 Whiteheadian
 process thought and French process thought
 (Gilles Deleuze,
 Alain Badiou). In addition, pointers to process-philosophical
contributions to the philosophy of religion are all but omitted, since
extensive and in-depth treatments are provided in the entries on
 Charles Hartshorne
 and
 process theism.



In order to support (Claim 1), two strategies have been pursued. The
first strategy is to argue that the core assumptions of the substance
paradigm--especially the focus on discrete, countable, static
individuals and the neglect of dynamic aspects--simply reflect
the cognitive dispositions that are typical for the speakers of the
languages in which Western metaphysics were mainly developed, such as
Ancient Greek, Latin, German, and
 English.[4]
 The second strategy is to select a well-known argument for the
necessity of substance-based metaphysics and to show that it involves
a *petitio principii*. For example, consider Peter F.
Strawson's widely accepted argument against the very possibility
of process
 metaphysics.[5]
 Strawson's argument can be reconstructed as follows:


1. For objective and identifiable concrete entities to be knowable,
they must be (i) distinguishable from other co-existents, and (ii)
reidentifiable for one or more members in a community of speakers and
knowers.
2. Distinguishability and reidentifiability are conditions of
"referential identification" for a community of knowers;
they require a matrix for the emplacement of our experiential
encounters with entities in a unified all-encompassing framework of
coordination.
3. Spatio-temporal location provides such a matrix; in order to
constitute the space-time framework essential for interpersonal
communication entities must "confer upon it their own
fundamental characteristics. That is to say they must be
three-dimensional objects with some endurance through time ...
They must collectively have enough diversity, richness, stability, and
endurance to make possible just that conception of a single unitary
[space-time] framework which we possess" (Strawson 1959, p.
39).
4. Only one category of entities possesses these required features:
"Of the categories of object which we recognize, only those
satisfy these requirements which are, or possess, material
bodies--in the broad sense of the expression. Hence given a
certain general feature of the conceptual scheme which we possess, and
given the character of available major categories, things which are,
or possess, material bodies must be [epistemologically] basic
particulars" (ibid.).



If this line of reasoning were correct, the substance paradigm would
be indispensable, and (Claim 1) above would be false. For it is clear
that any viable metaphysical theory must have room for identifiable
individuals that can be located in space and time. However, step (4)
in Strawson's argument begs the question on two counts.



All of the conditions that Strawson requires in step (3) (diversity,
richness, stability, and endurance or transtemporal sameness) arguably
are fulfilled as much by the entities that we conceptualize as
*physical processes* as by entities that "are or possess
bodies." For example, William Penn (2022) recently argued for an
exclusively process-based version of scientific realism--already
the praxis of natural science, but in particular also the scientific
models for the fundamental constitution of matter, commits to a
thoroughly processual ontology without underlying "basic
particulars": the stability of recurrent dynamic patterns does
not entail staticity. Furthermore, one might argue that the entities
we conceptualize as processes are physically realized without being
literally embodied, and for some of them it holds that we can point at
them and distinguish them ("this trickle versus that
trickle") and re-identify them ("the trickle was gone for
a minute, but then it came again"). In nature's
spatio-temporal framework we distinguish and re-identify *both*
things and processes. That Strawson's argument could have
appeared plausible is perhaps due to the fact that his illustrations
for processes are sounds and explosions, which are not, like many
other physical processes, lasting occurrences with determinate
location (such as fires, tornadoes, or waterfalls). The initial
plausibility of step (4) may also derive from a core assumption of the
substance paradigm, namely, the thesis that all processes can be
ontologically understood as modifications of substances. On this
reductionist view, all processes are 'owned' and we
identify them via their owner: the murder *of* Caesar, the
construction *of* the forbidden city, etc. But the fact that
these processes involve certain things and persons is merely one of
the aspects that an ontological interpretation of processes should
capture, and not a decisive one, since many processes (e.g.,
tornadoes, lightening bolts, today's rush-hour in New York) lack
a proper 'subject' altogether.



Even more important is the second question-begging element involved in
step (4) of Strawson's argument, for it displays the theoretical
bias of the substance paradigm at a more fundamental level. Strawson
sets up conditions for the ontological category or entity type that
can constitute a space-time framework and claims in step (4) (i) that
"things that are or possess bodies" can fulfill these
conditions, and (ii) that therefore such *things* are
"basic particulars." In this way Strawson turns a common
sense concept, viz. "material thing," into a basic
ontological category without asking whether it is possible that what
we common-sensically call a 'thing' might not also
ontologically be interpreted in terms of a category from process
metaphysics (e.g., as a bundle of activities or, in a Whiteheadian
fashion, as ongoing pattern of events). Strawson elsewhere rejects
such an interpretation as "revisionary metaphysics" while
metaphysics based on material things or substances is
"descriptive," but these adjectives are themselves in need
of a convincing justification--as long as an ontological category
fully captures the inferential content of a common sense concept, it
is as descriptive as any other.



In short, then, Strawson's argument fails on two counts. It is
simply not the case that material things are the indispensable basis
for a framework of knowable, uniquely located, re-identifiable items.
Physical processes of a suitable sort can accomplish this task as
well. Moreover, even if material things were the only candidates for
epistemically reidentifiable items, it still would be an open question
how we should interpret things ontologically. To be sure, the rebuttal
of Strawson's argument does not suffice to establish *Claim
1*, but it keeps process philosophy in the running.


## 3. Beyond traditional 'bifurcations': process-philosophical approaches to old questions



The best way to show that the core assumptions of the substance
paradigm are not laws of thought is to dispense with them while
working out philosophical accounts that are anchored in a new research
paradigm. Whitehead's philosophy still is the most
comprehensive, systematic, and detailed proposal for such a
fundamental theory revision, but, as often remarked upon, the depth of
Whitehead's philosophical revision does not make for easy
access. Accordingly, contemporary processists fall essentially into
three groups. The first group pursues the task of explicating
Whitehead's philosophy to the philosophical mainstream, e.g., by
putting metaphilosophical issues centerstage (Auxier and Herstein
 2017).[6]
 The second group adopts selected insights or elements of
Whitehead's scheme, partly without attribution, in order to work
out, in mainstream terminology, a solution to a specific problem. The
third group develops distinctly non-Whiteheadian routes into process
philosophy, guided by research in linguistics or new branches and
results of science. In the following the focus will be on the third
group, with occasional pointers to contributions to the second.



The last mentioned research line in contemporary analytical process
philosophy takes its departure from mid-20th century philosophical and
linguistic research on discourse about occurrences. Zeno Vendler
(1957) and Anthony Kenny (1963) argued that actions can be sorted into
various types according to certain logical and linguistic features of
verbs denoting these actions. The resulting classifications of
"action types" are similar, but Vendler's fourfold
division operated with fewer criteria and thus proved more
influential: whether a "verb" denotes a
"state", "activity",
"accomplishment", or "achievement" depends on
whether in present tense the progressive form needed, whether it can
be combined with the verb "finish," or whether it applies
an any moment of a temporal interval at which it applies. Certain
problems with Vendler's and Kenny's classifications were
first noted by linguists Henk Verkuyl (1972) and Barry Taylor (1977).
Most seminal, however, was Alexander Mourelatos' (1978)
observation that the distinctions that Vendler and Kenny tried to
capture do not pertain to the lexical semantics of "action
verbs" but to the semantics of entire sentences, and not of
sentences about actions but about occurrences in general. This renders
the classificatory task much more complex than Vendler and Kenny
envisaged. Since then the linguistic discussion has produced (under
the keywords "Aktionsart," "verbal aspect,"
and "aspectuality") a plethora of theories about the many
different ways in which natural languages express the dynamic aspects
of a situation. These linguistic theories provide essential data for
analytical process ontology, but one must not overlook that there are
language-specific interplays between verb semantics, tense system, and
aspectual meanings, and that ontology should be guided by inferential
differences that hold across
 languages.[7]



Informed by these early inquiries into the inferential characteristics
of occurrence types, analytical process ontologists have offered
various criteria sets for the classification of occurrences and their
relationships to other categories: some promote a division between
ongoing ("processes") and completed ("events")
occurrences, while others argue that ongoing occurrences should be
distinguished further into non-developmental and developmental
 processes.[8]
 There is also considerable disagreement on how to categorize these
occurrence types: are they concrete or abstract? Are they particular
or general entities? Mourelatos also showed that the logical criteria
of Vendler's and Kenny's classifications actually function
in two ways: they can be used to distinguish various types of
occurrences such as processes and events, but they also highlight
inferential analogies between processes and stuffs on the one hand,
and events and things on the other hand. Most analytical processists
characterize processes (or which ever label is used for the basic
category) as dynamic individuals that are concrete particulars or else
are abstract general patterns. By contrast, heeding the inferential
analogies in our reasoning about activities and stuffs, "General
Process Theory" rejects the presupposition that concrete
individuals need to be particulars: "general processes"
(or "dynamics") are introduced as a new ontological
category of concrete, dynamic entities that are non-particular (i.e.,
possibly multiply occurrent in space and time), determinable, and
"functionally individuated" (by contextually determined
sections of process
 networks).[9]
 However, both particularist and non-particularist interpretations
agree that processes cannot be individuated in terms of their
spacetime location *alone* and cannot be identified with
materially filled space-time regions, thus parting company with
"four-dimensionalism," (a position in contemporary
ontology that is occasionally misunderstood as a process-based
approach). Furthermore, while processists agree that processes combine
and that they exhibit common features, there is disagreement on how to
articulate such process combinations (e.g., by a special mereology),
and whether the shared patterns of processes belong into a different
category (as Whitehead suggested) or are themselves processes as
well.



In short, analytical process philosophy has worked out concepts and
theories of its own, however pedestrian and patchwork, as an
alternative to Whitehead's sophisticated system of categories,
and there is a multitude of approaches within analytical process
ontology. Besides different classifications of occurrences and
different ontological characterizations of processes, there appear to
be two research lines, one with focus on the role of processes in the
philosophy of time, action, or experience (see e.g. the work of Antony
Galton, Rowland Stout, and Helen Steward), and one with focus on the
role of processes in scientific reasoning (see section 4 below).
Despite all differences in constructive detail, however, Whiteheadian
and non-Whiteheadian process philosophy both recommend themselves as
gateways to renovating philosophical discourse by deconstructing
traditional dichotomies. Here are just a few of the topics where
processists promise philosophical advance.



(i) Beginning with a familiar Whiteheadian move, the rejection of the
traditional "bifurcation of nature" into a physical and a
mental domain, the process approach opens up new ways of looking at a
wide variety of issues, and in particular on the relationship between
mind and nature. Whiteheadians argue that the traditional mind-body
problem dissolves if all basic constituents of reality are short-lived
processes of information transfer that exhibit both
'mental' and 'physical' aspects in different
accentuations according to context. Quite independently of
Whitehead's philosophy and commitments to panpsychism, a number
of analytical philosophers have argued that the present-day debate in
philosophy of mind and philosophy of action has been hampered by an
ontology that is focused on upshots (states, and state-like events)
and promote a theoretical 'Gestalt' switch in the
metaphysics of experience and agency (Stout 2017). Helen Steward
(1997, 2012) criticizes the standard conception of perception and
agency as a causal sequence of states, some of which are physical and
some mental; in order to make room for agentive freedom within the
natural world Steward proposes that we view agency as a special form
of downward causation, taking our bearings from the hierarchical
systems of functioning in biological organisms (2017). Others have
pointed out that our common sense (teleological) explanations of
actions commit us to ongoing occurrences (Stout 1996) or that we can
best make sense of the unity of our experience if we take processes to
be the objects of our experiences rather than states or things
(Soteriou
 2013).[10]
 The so-called "dynamical hypothesis" in cognitive science
(Van Gelder 2000) generated a line of philosophical research on
dynamic models of the mind that is strongly guided by scientific
research, especially by cognitive science using a connectionist model
of the mind (see below).



(ii) Similarly, as non-Whiteheadian analytical processists have
pointed out, process metaphysics reconfigures the traditional problem
of universals since it abandons the substance-metaphysical principle
that concrete entities are fully determinate while general or
indeterminate entities are abstract (i.e., they must not be, undergo,
or initiate
 changes).[11]



(iii) Processists also have offered novel approaches to the problem of
persistence, either by taking persistent entities to be
"enduring" patterns of processes (Whitehead), or by
questioning the idea that "perdurance" vs.
"endurance" accounts of persistence form a theoretically
necessary exclusive
 dichotomy.[12]



(iv) The dichotomy of 'fact' and 'norm,' some
processists argue, is another traditional "bifurcation"
that can be bridged. Some natural processes realize a certain form of
low-degree normativity. In some process organizations (e.g.,
far-from-equilibrium systems) each component process presupposes every
other for its own occurrence; in the context of these particular
process organizations the dependence amongst the single processes is
not merely a matter of linear causation but constrained by the
simultaneous interactions of the entire system, ensuring that each
process is 'functional for' the occurrence of the
 system.[13]



(v) Finally, the process approach also can be used to sidestep
traditional dichotomies in the philosophy of religion. While the
opposition between "immanence" and
"transcendence" traditionally is taken to amount to an
exclusive alternative, whether in application to universals or to God,
the tools of process metaphysics allow us to pursue a third option
that exploits the explanatory grammar of the 'mode.' We
often consider the mode or way in which a process, or collection of
processes, occurs as a separate kind of process (compare, e.g.,
scratching a violin string with a bow vs. playing a tone on the
violin; or a free market economy vs. a planned economy). Processes
that are modifications of other processes are both immanent in the
sense that they affect (by constraining and enabling) how the modified
processes occur, but are transcendent in the sense that they are
multiply realizable, that is, they are not themselves dependent on the
particular spatio-temporal occurrences of the processes that realize
 them.[14]



In addition, there is a host of other contemporary issues where
attention to processes generates novel answers that advance our
understanding of the familiar questions of philosophy in important
ways, even without challenging some central, defining, dichotomy.
Cases in point are the 'process account of causation'
(Salmon 1984,
 1997)[15]
 or N. Rescher's processist analysis of knowledge. Offering
detailed reconstructions of the procedures of knowledge production,
Rescher argues that rational inquiry, including science, is the
process of creating coherent theories that systematize what we have
established as data with increasing complexity (Rescher 1982). That
this method of inquiry can yield (temporary) truths is justified by
its practical success, but the method is essentially (a) interminable
and (b) progressive, since: (a1) each knowledge claim contains
presuppositions that raise new questions; (a2) reality is
"cognitively inexhaustible"; and (b) since the increasing
complexification of scientific knowledge can count as cognitive
progress, even though such progress may not be discernible as
cumulative or linear advance (Rescher 1977, 1978, 1984). For claims
(a2) and (b) Rescher supplies process-metaphysical underpinnings,
endorsing a view of nature as continuously evolving and a view of
evolution as directed towards increasing complexity (Rescher 1996,
2006 ch. 10, and 2012; see also below section 6).



Perhaps the clearest example for the progress that a processist
approach can bring to longstanding tasks of philosophy is in the
theory of selfhood and personhood. Whatever cultural notions of
'person' and 'self' we may have acquired, our
immediate self-awareness reveals us to ourselves as engaged in doings
and undergoings. What we find ourselves to be doing and undergoing we
understand as belonging to a space of possible occurrences. We notice
patterns in what might possibly be going on with us, and some of these
patterns we use to identify ourselves: in terms of our talents,
skills, capabilities, traits, dispositions, habits, inclinations, and
tendencies to action and inaction. It is integral to your
self-awareness at this moment that your reading is *yours*, the
reading of a self that is the same over time. But the sameness of this
self we experience not as the sameness of a time-invariant thing but
as the sameness of an 'operation' of integration--an
ongoing unification of experienced patterns in ways that enable a
first-person perspective. Some process philosophers have taken the
experience of dynamic sameness in self-experience as the basis for
constructing a process-metaphysical account of personhood that defines
the core self as a unified manifold of actions and capacities,
tendencies, and dispositions to (physical or psychical) actions (see
e.g. Rescher 1996 ch.6). In this way they preserve a concept of
personhood that renders the self or ego experientially accessible. The
unity of a person is a unity of experience--the coalescence of
all of one's diverse micro-experiences as part of one unified
macro-process. Importantly, processists do not equate the
cross-temporal unity of a person-process with a sequence of momentary
total states of consciousness, as neo-Humean accounts currently
postulate; rather, it is the sort of unity of process that links each
minute's happenings into a single overall journey. From the
process point of view a self just *is* the complex process
composed of various physical interactions, experiences, feelings,
moods, and actions in their systemic interrelationship. The whole
individual person is continuously 'in the making' or being
constituted, yet it also continuously influences which components
(e.g., experiences, feelings, actions) enter into the constitution of
the whole and in which ways these components occur. Such circular
dependencies between a whole and its parts cannot be accommodated
within a theory of individuals that is committed to the basic
constructional principles of the substance paradigm, especially the
claim that concrete individuals are fully determinate. Relationships
of mutual constitution are legitimate theoretical tools within process
ontologies where entangled recursive definitions are not in conflict
with basic tenets about individual entities. By extending the dynamic
dependencies among the component processes of a self to include
aspects of the person's physical and social context, a process
account of persons can formulate in a differentiated and
scientifically informed fashion various claims about the formative
role of our
 environments.[16]



Harking back to (Claim 2) and (Claim 3) above, extant process-geared
treatments of familiar topics surely provide considerable support for
the claim that process philosophy is viable (Claim 2). But in the eyes
of many processists (Claim 3) matters most--as the next section
will sketch, currently it may be process philosophy's primary
asset that it enables us to articulate and address important new
questions raised by modern science.


## 4. Tracking science: new topics for process philosophy



The relationship to science and technology appears to mark a
distinctive difference between continental process philosophy
(Heidegger, Deleuze, Badiou) on the one hand, and, on the other hand,
early American process philosophy (Peirce, James, Dewey, Whitehead,
Mead) as well as current analytical process thought. While the former
develops a critical point of view to reflect on the enterprises of
science and technology as cultural objects, the latter aligns its
investigations with the aims and results of science and technology,
often with an explicit commitment to naturalism. In fact, the early
phase of process philosophy in America was mainly motivated by an
effort to come to terms with the far-reaching philosophical
implications of the Darwinian theory of evolution. For these early
American process thinkers evolution was an emblematic and paradigmatic
process--it seemed to provide a clear template for understanding
how novelty and innovation come into both the human world and the
world of nature. The evolutionary framework calls for a new
metaphysics, the American pragmatists argued, which could articulate
the pervasive role of process and of the passage of time. Was there a
vehicle or substance that could 'carry' physical,
biological, and cosmic evolution? If neither individuals nor types
(species) of things are time-invariant, a new account of being was
needed that had room for the emergence of novelty in nature, and could
convey a sense of human existence as both "precarious and
stable" (Dewey). The idea that evolution was a fact that
philosophy had to accommodate explains many of the elements of early
American process thought, in particular the understanding of
dynamicity as a force of creating novelty, as well as the need to take
a stance on the question whether the overall process of reality is
directed or blind--which ultimately split the group (see section
6).



Present-day contributions to analytical process philosophy are no
longer driven by an attempt of making sense of evolution. However,
they are often still motivated by the view that there are certain
results in science that philosophy simply must come to grips with, and
if this task involves a fundamental revision of the standard tools of
philosophy, then philosophy should provide new conceptual tools. For
quite some time researchers in the philosophy of biology and in the
philosophy of chemistry have argued that process-based or
process-geared approaches yield better ontological descriptions of
these domains, i.e., better capture the inferential content of the
basic concepts of biology and
 chemistry.[17]
 The case of biology provides particularly strong empirical
motivations for a 'process turn,' as witnessed by a recent
collection of research in philosophy of biology that deserves special
attention since most of its contributors do not proceed from but
arrive at process-ontological theses (Nicholson and Dupre
2018). As the editors point out, metabolism, lifecycles, and
interdependencies between genetics and ecology--that is,
processes that occur both at the level of cell biology as well as at
the level of multicellular organism--present three classes of
biological phenomena that in different ways dismantle
substance-ontological presumptions; these phenomena call for an
ontology that treats transtemporal sameness as a time-scale dependent
feature of process systems and models organisms no longer as
independent and comparatively discrete substances but as a complex
network of internal and external
 interactions.[18]



Beyond chemistry and biology there are other scientific domains where
scientific progress suggests process-ontological redescriptions since
the conceptual contents of the relevant scientific terms cannot,
without problematic distortions, be analyzed in terms of the
categories of substance metaphysics. However, there are also
scientific domains and topics that *directly* imply a
process-ontological interpretation since the researchers working in
these areas already have adopted processist idioms in their informal
glosses of mathematical descriptions and in their heuristic approach
to the domain. Cases in point for a 'process turn' within
science itself are (i) quantum physics, (ii) self-organization, and,
most recently, (iii) cognition.



(i) *Quantum-physical processes:* When Whitehead turned from
mathematics to philosophy, he was quite aware that recent developments
in physics (the demise of classical atomism in the face of quantum
theory and relativity theory) had thrown out our old common-sense
vision of the order of the universe. Quantum physics brought on the
dematerialization of physical matter--matter in the small could
no longer be conceptualized as a Rutherfordian planetary system of
particle-like objects. The entities described by the mathematical
formalism seemed to fit the picture of a collection of fluctuating
processes organized into apparently stable structures by statistical
regularities--i.e., by regularities of comportment at the level
of aggregate phenomena. During the early decades of the twentieth
century process philosophers were excited by the evidence that physics
had turned the tables on the core refuge of substance metaphysics:
classical atomism. Instead of very small *things* (atoms)
combining to produce standard processes (avalanches, snowstorms)
modern physics seemed to suggest that very small processes (quantum
phenomena) combine to produce standard things (ordinary macro-objects)
as a result of an as yet not understood *modus operandi* that
could, nevertheless, be mathematically described. So-called enduring
"things" in this picture would come about through the
emergence of stabilities in statistical fluctuations, as a stability
wave in a surging sea of process, metaphorically speaking.



Contemporary quantum physics has produced a more diversified theory
landscape, and it is an open question whether we have moved beyond the
point where Whitehead's metaphysical transposition of the field
concept is still pertinent, or could be adjusted to interpret also one
of the currently competing
 theories.[19]
 However, very generally speaking, there are at least four basic
aspects of our current views of the quantum-physical domain that seem
to favor a process metaphysics, whether Whiteheadian or
non-Whiteheadian. First, as the so-called 'problem of identical
particles' indicates, in the microphysical domain individuation
and countability fall asunder, which calls for an ontology of
'subject-less' processes that *are* the features by
which we individuate quantum-physical entities, but occur in countable
units only relative to interaction context. Second, if spacetime is
quantized and emergent, metaphysics cannot operate with basic entities
that are individuated in terms of their spacetime locations. Third,
the "measurement problem" presents a particular difficulty
for substance metaphysics, since the latter rests on the assumption
that all individuals are fully determinate independently of their
interaction context. In contrast, process metaphysics endorses the
principle that 'interaction is determination.' Fourth,
quantum entanglement (e.g., in EPR-Bohm systems) seems a clear-cut
example of ontic emergence that substance metaphysics cannot
accommodate; while some systems properties (e.g., weight) can be
construed as resulting directly from the causal properties of the
elements of a collection of persistent substrata, the correlations
that measurements on entangled quantum entities display cannot be
interpreted in this fashion since the properties of the components of
the system do not exist independently of the measurement performed.
The measured correlations thus are properties of an interaction and
not of any substance. While working quantum physicists often are
hesitant to attempt any conceptual explication of mathematical models
of quantum physical processes, Carlo Rovelli is a notable exception.
Rovelli's relationist interpretation of loop quantum gravity is
committed to an understanding of physical being as becoming in a
radical sense, as a sort of change that does not presuppose a
pre-existing spacetime
 framework.[20]



Interestingly, via the unlikely subject of an ontology of quantum
physics, new points of contact have opened up between analytical and
('continental') interpretive process thought in Karen
Barad's metaphysics of "agential realism" (Barad
2007). Grounded in a detailed interpretation of the philosophy of
Niels Bohr, Barad views reality as the entanglement of natural and
social"agencies" the distinctness of which emerges in the
specific "intra-actions" produced by specific physical
set-ups (experiments); the continuous "intra-activity" of
reality, Barad argues, calls for a non-essentialist, performatist
understanding of meaning and values.



(ii) *Self-organization:* Process metaphysics traditionally has
been motivated by the fact that it seems to give the best explanation
of the phenomena of diachronic emergence, originally understood as an
integral feature of evolution. Since the development of scientific
theories of "self-organization," "chaos," and
"complexity" have begun to alter our understanding of
evolutionary change, there is a new need for a metaphysics that can
accommodate all sorts of phenomena where dynamic organizations exert
causal constraints. While older, speculative, process metaphysics
embraced the idea of purposes and creativity in nature, and allowed
for the explanatory category of a 'self-realizing' or
'self-engendering' entity (in various terminological
guises), present-day analytical processists confine themselves to
arguing that "downward causation" becomes perfectly
intelligible once physicalism has been divorced from the assumptions
of the substance paradigm, and especially from the principle that
causal powers cannot be attributed to dynamic
 organizations.[21]



(iii) *Embodied cognition:* The turn to "embodied
cognition" in cognitive science provides another strong
motivation for the turn to process in metaphysics. The standard model
of cognition as the computation of symbolic representations fits well
with the assumptions of substance metaphysics and suggested a pleasing
analogy to classical atomism: mental operations effect relational
change of cognitive atoms. But the first rivals to the standard model,
connectionism and the so-called "Dynamic Hypothesis" (Van
Gelder 2000), were constructed along largely process-ontological
lines, replacing the classical conception of cognitions as discrete
abstract objects that represent concrete things outside the head with
a dynamic conception of cognitions as modes of functionings of a
neural net or of process organizations. The neural network model of
the mind dominates in recent cognitive science and neuroscience where
mathematical models of "predictive processing" (see the
entry on
 connectionism).
 In parallel with the development of the connectionist model of the
mind, proponents of "interactivism" and "embodied
cognition" argued that the bodily interaction of an organism
plays a constitutive role in cognition. A key notion for the early
debate about the'embodiment thesis' was the concept of
"structural coupling," a phase in the contemporaneous
development of two systems (e.g., organism and environment) where
mutual dynamic dependencies unfold across system boundaries. During
the last decade researchers working in the intersection of cognitive
science and philosophy of mind appear to have adopted the "4E
model of cognition", holding that cognition is not only
embodied, but also "embedded, enacted, and extended"
(Newen et al 2018). The 4E model of cognition is explicitly committed
to a process view but much ontological work remains to be done in
order to distill biologically relevant process architectures from the
statistical formulas (e.g., "Markov blankets") that
characterize neural network
 behaviors.[22]


## 5. Current challenges



Process philosophers share the view that being is dynamic or that
there are no concrete static entities; however, as stressed throughout
this entry, there are also profound differences in the way process
philosophers work out this basic intuition in their descriptions of
the structure of reality and our understanding of it. Which of the
competing approaches to process philosophy can count as the currently
most promising? If processist theories recommend themselves in terms
of their explanatory force, as offering new solutions to old problems
(section 3), or better conceptual resources for new tasks (section 4),
then surely explanatory force should also be the standard for
evaluating processist theories. But while cross-paradigm explanatory
advantages in the sense of sections 3 and 4 can be gauged more
straightforwardly, this becomes rather more difficult at the level of
intra-paradigm comparisons. Does the wide scope of Whitehead's
philosophy of organism outweigh the fact that all explanatory
technical terms are dissociated from the rest of philosophical
discourse? Or again, is the explanatory force of a formal axiomatic
process ontology greater than a process metaphysics formulated with
the means of common sense terms whose meanings are carefully
gerrymandered, or one that operates with a network of metaphors and
relies on the reader's hermeneutic response? Should depth and
detail of the ontological description matter less perhaps than the
impressive explanatory scope of a consistently naturalist process view
of "The Whole Person", from microphysics to macrosociology
(Bickhard 2022)? Here, at the intra-paradigm level, arise all the
far-reaching methodological questions that surround philosophical
explanation in general. Setting these larger questions aside, and
focusing just on processist work in the style of analytic philosophy,
the explanatory force of a processist theory may depend on how well it
addresses the following challenges.



The first challenge is to define the notion of dynamicity itself. If
the individuals of a processist theory are 'dynamic'
rather than 'static,' how can we make sense of this new
category feature? Some processists say that a process or dynamic
entity is denoted by an English sentence in the progressive,
or--less closely tied to the peculiarities of English
grammar--by sentences licensing certain inferential patterns of
aspectual meaning (see
 footnote 6).
 In both cases the definitional task is thus deferred to linguistic
theories of aspect; these theories, however, take the term
'dynamic' to be understood. Alternatively, one might
return to Aristotle and define dynamicity as the actualization of a
potency or capacity. Such metaphysical expenditure can be justified if
we need to embrace a notion of the 'real' as characterized
by actuality and potentiality anyway in order to arrive at a plausible
interpretation of quantum physics (as argued in Eastman et al 2016 and
Eastman 2020). A third, naturalist, strategy for defining different
types of dynamicity has been suggested by Terrence Deacon, who
introduces an ontological label ("homeodynamics") for the
processing that realizes the tendency of energy dissipation
characterized by the second law of thermodynamics, and describes the
emergence of two other forms of dynamicity
("morphodynamics" and "teleodynamics") in
terms of relationships of processes constraining each others'
tendencies for thermodynamic dissipation (Deacon 2012). Since some of
those processual constraints are self-referential in the sense that
they prevent (constrain) the thermodynamic dissipation of
processing-under-such-constraints--a process architecture that
Mark Bickhard labeled "recursive self-maintenance"
(2004)--Deacon's approach to an understanding of dynamicity
not only picks up on metaphysical insights of articulated in Buddhism
and Daoism (Deacon and Cashman 2016), but also resonates with the
fourth strategy of defining dynamicity, championed in German Idealism.
Notwithstanding profound differences in systematic embedding, Fichte,
Hegel, and Schelling exploit the semantics of self-referential
propositions to convey a dynamic understanding of being that is
'presence without availability', i.e., a
'presence' that can be grasped by, and as such has the
character of, a non-terminating recursion. A fifth strategy for
addressing the task of defining dynamicity would be to reject the task
and to directly challenge the idea of being as static. For example,
one might argue that we may be able to think coherently that
geometrical shapes have a sort of being that is static or unchanging,
but physical entities this is not possible, since it would imply that
physical properties can be literally possessed *at an instant*
of time.



The second challenge is to state precisely how processes relate to
space and time. Does a commitment to a process metaphysics imply a
certain metaphysics of time? Do processes in some fashion constitute
space and time, as Whitehead postulated? Or are they occupiers of
spatiotemporal regions like perduring entities, just not static (and
thus, for example, providing better support for presentist accounts of
time than classical substances)? Upon a closer look, the distinction
between "perdurance" and "endurance" (Mark
Johnston, David Lewis), which is commonly (though perhaps not quite
correctly) linked to W.E. Johnson's distinction between
occurrents and continuants, sits badly with a process ontology. For
'activity-like' processes (e.g., snowing) somehow seem to
take time just as perduring entities do, yet are "wholly
present" at every time at which they exist, just like enduring
entities or continuants. Several authors thus have pointed out that
processes behave like
 continuants.[23]
 As mentioned above in section 3, this opens up a new solution path
for the problem of persistence, but it also calls for a clear account
of how ongoing developmental and activity-like processes are situated
in time and space, and how they relate to extended temporal and
spatial regions. Moreover, if processes relate to space and time in
ways that does not allow for individuation in terms of spatiotemporal
location, how else do we individuate processes? Should we take our
bearings from scientific practices of individuating particular
processes (Pemberton 2018) or can we, at least for some types of
processes, lay down general conditions to determine which processes
are parts of particular process individuals (Kaiser 2018)? For those
who take processes to be (abstract or concrete)
"type-like" non-particulars the question of individuation
can be addressed in the same way in which we individuate types,
namely, by classificatory taxonomies that, among other criteria,
relate to the way in which processes occur in space and/or time.
 [24]



The third challenge consists in describing the different ways in which
processes relate to each other and especially, how they combine. Since
process combinations may engender emergent processes, and also in
other regards do not abide by the laws of Boolean algebra, neither set
theory not classical extensional mereology can be used as formal
frameworks ontologically to describe and classify different types of
process combinations. Moreover, since the parthood relation on
processes is not transitive, at least when processes are not
identified with extended spatiotemporal regions, further deviations
from the classical axiomatization of the parthood relations are
necessary to formalize a mereology on
 processes.[25]
 Alternatively, some authors suggest representing process
architectures with the means of mathematical category theory. Since
some category-theoretically defined notions of compositionality
restrict decomposition, proponents of "applied category
theory" argue that interdependencies of (the identity of) wholes
and parts in process structures also can be represented within this
formalism without incurring substance-ontological commitments. Some
authors recommend category theory for a formal Whiteheadian approach
to process metaphysics (Ferrari 2021, Auxier & Herstein 2017),
while others use it to formulate notions of compositionality that can
be applied across domains from computer science to quantum physics
(Coecke 2017). Also systematic connections between process structures
can be captured category-theoretically, as Phillips and Wilson (2010 )
show the case of the systematicity of cognitive capacities. Besides
mereology and category theory, some authors explore formal dialectical
theories in order to describe the "logic" of real changes
(Brenner and Igamberdiev 2021).



The fourth challenge is more fundamental. If any of the basic
theoretical terms of the many process philosophies, past and present,
are to have explanatory value at all, there must be a way to tie the
process philosopher's basic intuition to ordinary experience.
After all, the purpose of philosophy is to enhance human
understanding, and the core concepts of philosophical explanations
must in some fashion be anchored in what we intuitively understand
from everyday experience. In fact, some process philosophers (e.g.,
Whitehead) argue that the traditional notion of substance (a
time-invariant, necessarily uniquely located particular) precisely
lacks any experiential grounding. On the other hand, substance
ontology has been capitalizing on the fact that the canonical
illustrations of substances, things or living things, loom large in
our practical interactions. The explanatory force of a process
ontology thus will depend on whether it is possible to identify a
similarly salient canonical illustration for whatever technical notion
of process is postulated as basic category. Some process approaches
use self-experience as anchoring canonical illustration for postulated
technical notions of dynamic sameness and unity, but one might worry
that this model is all too complex.


## 6. The ultimate question: is reality directed?



As emphasized throughout, process philosophy is a complex and highly
diversified field that is difficult to describe in more than general
and disjunctive terms. In conclusion this section will highlight a
topic on which contemporary process philosophers are fundamentally
divided, to the extent that one group believes that the entire issue
is ill-conceived.



As Rescher (1996, ch. 5) points out, processists fall into two
principal camps. On the one side is the teleological (and often
theological) wing that sees nature's processuality as a matter
of teleological directedness towards a positive destination. On the
other side is the naturalistic (and generally secularist) wing that
sees nature's processuality as a matter of an inner dynamicity
without any directness or at least without any directedness towards a
specifiable destination. Both agree in according a central role to
inherent dynamicity in nature. But the one (naturalistic) wing sees
this in terms of randomness that leads in arbitrary ways away from the
settled formulations of an established past, while the other
(teleological) wing sees this in terms of a goal-directed
purposiveness preestablished by some value-geared directive force.



The division between secular and theological process philosophy has
its roots in the early phase of contemporary process thought in late
19th and the first half of the 20th century, and centers on two views
of evolutions. For secular, atheological processists evolution
typifies the creative workings of a self-sustaining nature that
fulfills the vision of a certain positivist program, dispensing
altogether with a God function to explain any of the events in or
appertaining to the
 universe.[26]
 For theological processists like Teilhard de Chardin, however,
evolution exhibits God's handwriting in the book of nature.



Present-day processists, who in the main no longer take Darwinian
evolution as a concept or phenomenon that demands a commitment for or
against theism, are wont to point to possible areas of agreement (see
Rescher ibid.). First, present-day processists point out that both
secular and theological protagonists of process thought can see
evolution not only as a crucial instrument for understanding the role
of intelligence in the world's scheme of things but also as a
key aspect of the world's natural development. In addition, both
secular and theological processists can agree that the evolutionary
process provides process philosophy with one of its main models for
how large scale collective processes can inhere in and result from the
operation of numerous small-scale individual processes, thus
accounting for innovation and creativity also on a macro-level scale.
Second, present-day processists draw attention to the fact that early
process thinkers were divided in their assessment of the phenomenon of
evolution, since they failed to draw a division within the phenomenon
of evolution itself. Undoubtedly, human intelligence is based on
teleologically blind natural selection operating with random mutations
to produce the neurophysiological capacities of the human brain.
Cultural evolution, on the other hand, does not share these features
and could well appear as in some sense directed. For example, one
might argue that cultural evolution is generally Teilhardian, in that
it is governed by a rationality-geared selection among purposefully
devised mutational variations. Cognitive evolution involves both
biological and cultural components, superimposing non-random rational
decision-making on biological selection. Our cognitive capacities and
faculties are part of the natural endowment we owe to biological
evolution. But our cognitive methods, procedures, standards, and
techniques are socio-culturally developed resources that evolve
through rationality-geared decision making in the process of cultural
transmission through successive generations. Our cognitive hardware
(mechanisms and capacities) develops through Darwinian natural
selection, but our cognitive software (the methods and procedures by
which we transact our cognitive business) develops in a Teilhardian
process of rationality-geared decision-making that involves purposeful
intelligence-guided variation and selection. In the eyes of
present-day processists--at least those that no longer pursue
speculative process thought--it is for scientific research to
decide whether, and to what extent, the relationship between
biological and cognitive evolution can be understood on the analogy
that 'biology produces the instrument and culture writes the
music,' with the instrument constraining the playable music, and
not *vice versa* (cf. Rescher 1996 ch. 5 and Rescher 2006 ch.
10).



There is a middle ground between strict theological teleology on the
one hand, and, on the other hand, the naturalistic view that there is
no final end that all processes are ultimately directed towards.
According to this third alternative, a 'soft' version of
the teleological position, process is progress. For, so goes this line
of reasoning, one can draw a lesson from evolutionary theory about
collective progress despite contingency and mortality at the scale of
the individual organism. In the small - i.e., item by item
- nature's processes are self-canceling: what arises in
the course of time perishes in the course of time. But nevertheless,
so the argument goes, (i) the overall course of processual change
tends to the development of ever richer, more complex and
sophisticated conditions of occurrence. Moreover, Darwinian
evolutionism suggests (ii) that



> 
> 
> ... the arrangements which do succeed in establishing and
> perpetuating themselves will as a general tendency manage to have done
> so because they represent actual improvements in one way or another.
> ... Accordingly, fruitfulness in the long run compensates for
> transiency and mortality at a smaller scale of occurrence. (Rescher
> 1996: 102)
> 
> 
> 



These two central premises for soft teleology are quite substantive,
however. Premise (i) presupposes that (iii) there is a general and
comprehensive measure of simplicity or complexity that could be
applied to natural and cultural processes in order to claim an overall
tendency of development towards increased complexity; in particular,
such a measure of complexity should make it possible to offset
decreases of complexity with respect to one parameter by increases in
complexity relative to another parameter. Premise (ii) presupposes
that (iv) species survival can be taken as an indication of some
aspect that meaningfully can be connected to the axiology of progress.
Whether the optimism of the soft teleological position is justified
thus ultimately depends on the tenability of claims (iii) and
 (iv).[27]
 The fact that the premises for soft teleology have direct
implications for our current debate about transhumanism endows the old
question of the directionality of reality with unexpected practical
relevance for the regulation of artificial intelligence and
robotics.


## 7. Institutionalization



Process thought constituted a prominent sector of the active
philosophical scene in the USA during the first half of the 20th
century. Apart from the proliferation of books and articles on the
topic, it has achieved considerable institutionalization in the USA
during the years after World War II. Indications of this phenomenon
include the formation of the *Society for Process Studies*, as
well as the prominence of process philosophizing within the aegis of
the *Society for American Philosophy* and the *American
Metaphysical Society*. Another clear token is the journal
*Process Studies*, published by the *Center for Process
Studies* in Claremont CA, and founded in 1971 by Lewis S. Ford and
John B. Cobb, Jr., a publication that has become a major vehicle for
article-length discussions in the field. Representatives of process
philosophy occupy influential posts in departments of philosophy and
of religious studies in many of American universities and colleges,
and some half-dozen doctoral dissertations are produced annually in
this field. But contemporary process philosophy is not geographically
confined. In 2002, the publishing house Ontos in Frankfurt, Germany,
launched a book series on "Process Thought"; though taken
over by DeGruyter in 2015, over 25 volumes have appeared. In Europe
the *Center for Practical Philosophy* at the Universite
du Louvain, Belgium, directed by Michel Weber, is a focal point for
research on, and applications of, international process philosophy.
The Bulgarian Academy of Science recently created a *Center for
Process Studies* for philosophers and computer scientists. The
*German Whitehead Society* regularly organizes conferences and
summer schools on both Whiteheadian and non-Whiteheadian process
thought. The *International Process Network*, recently launched
by Mark Dibben at the University of Tasmania, Australia, is a new web
community of international process philosophers of all philosophical
proveniences East and West. Even though process philosophy is not
institutionalized as such everywhere in the global field of
philosophy, it is a research paradigm that currently is in use all
around the world.