Broadly understood, process philosophy refers to any position that gives the central place to flux or becoming. heraclitus, hegel, spencer, bergson, peirce, james, S. alexander, C. Lloyd Morgan, Dewey, G. H. Mead, and teilhard de chardin have all been classified as philosophers of process. (The best survey of process philosophy in this sense is Nicholas Rescher's Process Metaphysics.) The term is used principally to refer to the philosophies of A. N. whitehead and C. hartshorne, and this narrower usage has gained increasing currency since it was introduced by Bernard Loomer in 1946. In this philosophy events (actual occasions) are the primary actualities. Enduring substances are reconceived as series (societies) of these occasions, each repeating the society's common defining characteristic, which functions much like an Aristotelian substantial form. Each occasion is self-creative. In other philosophies causes are conceived as active agents producing passive effects. Whitehead reverses this, treating effects as actively producing themselves in appropriating their causes.
Whitehead. The model for such causation is perception, understood in a Kantian sense as the mind spontaneously organizing and unifying its sensations into a single, intelligible experience. Perception is then generalized by abstracting from it any necessary reference to consciousness. Prehension, the more general concept, means any (conscious or unconscious) taking account of another. An occasion is then the growing together or concrescence of its prehensions. The way B prehends A is the way A causally influences B. Thus physical causality and mental experiencing are unified to overcome Cartesian dualism.
Each occasion is an atomic unit of becoming. Physical (objective) time consists of these droplets of self-creation, each with its own temporal thickness. Each is a process of determination whereby an indeterminate multiplicity of causal factors is transformed into a determinate past. Past actualities are determinate and fixed, yet as objectified they function as causal factors for the occasions now prehending them. Whatever is objective (since determinate) is therefore past. This means that all present immediacy is subjective. Thus subjectivity is presentness, for the only present immediacy we can ever directly experience is our own subjectivity. Since only determinate elements can be prehended, even the objective components of our present experience must be considered past, for the events we directly experience must already have occurred in order to be experienced. This identification of subjectivity with temporal immediacy entails a pansubjectivity akin to panpsychism. Since every occasion concresces in the present, it must then enjoy its own subjective immediacy. Its present can only be expressed in subjective terms if distortion is to be avoided, since the present can never be objectively experienced.
However, we must not anthropomorphize subjectivity by endowing every occasion with the characteristics of human experience. Subjectivity is regularly confused with mentality and consciousness. If subjectivity is the general capacity to be influenced by actuality, mentality is the capacity to be influenced by possibility, especially by novel possibility. Consciousness is a more specialized contingent feature of some highly complex occasions displaying massive mental originality. Few occasions in the universe are conscious; many display noticeable degrees of mentality (novelty); all are equally subjective.
If each occasion actively produces itself, its "causes" need only be prehensible objects, which can include possibilities, values, and ideals in addition to past actualities. Since no occasion can integrate all the conflicting tendencies of its inherited past, each must have a "subjective aim" or ideal of what it should become. This aim functions as a principle of selection by which to appropriate the past. It both affects and is affected by the influence of the past, and this reciprocal interaction constitutes the occasion's freedom. Since it becomes the final form of the determinate outcome, the subjective aim is the dynamic, emergent counterpart of an essence or substantial form, but one particularized to each individual actuality.
The occasion's subjective aim cannot be derived from its own past taken collectively, since it must function as a means for selecting amidst this welter of incompatibilities. Nor can the ideal be derived from some single past actuality, since every occasion has a different past and needs a different principle of selection. Occasions may, and often do, have privileged past occasions to serve as their predecessors, but then the origins of these predecessors must be taken into account. Ultimately these individual ideals must be derived from an actuality that is not a temporal occasion, namely God. God's power is the worship he inspires through the ideals provided to each occasion. God creates by the way in which he persuades each creature to create itself.
Hartshorne. Hartshorne's conclusions are basically similar to Whitehead's, but his characteristic mode of argument differs. He sets up a series of polar opposites, and then asks which is the more inclusive, which can best account for its opposite. If neither can include the other, we have irreconcilable dualisms. Thus he argues for panpsychism on the grounds that mind can account for matter, but not matter for mind. Freedom can account for whatever causal determinism there is, while determinism can only account for freedom by explaining it away. Becoming (change) includes being as an abstract aspect of itself, while being cannot include change without thereby changing. God as the perfect being supremely worthy of worship is not to be conceived merely in terms of one set of these categories to the exclusion of their opposites, but as the eminent instantiation of both sets. Thus God's omniscience is abstractly absolute as utterly free from error and ignorance, but concretely relative to what in fact there is to know. In championing this logic of perfection, Hartshorne defends the ontological argument, but applies it only to God's abstract essence, not his concrete actuality. The abstract essence is eternal and necessary, but the concrete actuality is temporal, contingent upon the divine experience of an emerging world. God knows all there is to know, the actual as actual, the possible as possible, but future contingents cannot be known as determinate actuality.
Because of its clarity, cogency, and accessibility, Hartshorne's version of process philosophy has been enormously influential. A major divergence among process thinkers centers on whether Whitehead's concept of God as an everlasting concrescence is correct, or whether it must be revised as an ongoing series of divine occasions. Cobb has worked out this Hartshornean revision most extensively, while Christian and others favor the original concept. Ford also affirms an everlasting concrescence but has made other far-reaching modifications in order to insure God's effectiveness in the world.
New Developments. Whitehead's unfamiliar terms and conceptuality presented formidable difficulties to early readers of Process and Reality. Between 1958 and 1966 a new era in process studies was inaugurated by the publication of three excellent aids: Leclerc's introduction, Christian's commentary, and Sherburne's Key. The Key is a heavily abridged and rearranged version of Process and Reality, with notes and glossary, well designed to facilitate the reader's understanding of the system.
Besides its obvious relevance to process theology, process philosophy has been applied to aesthetics, evolutionary theory, physics, biology, the analysis of religious language, biblical studies, literary criticism, political science, the theory of civilization, and the history of religions (particularly Buddhism). A Center for Process Studies has been established at the School of Theology in Claremont, California, which also publishes a scholarly quarterly, Process Studies.
Criticisms. Process philosophy has been criticized by proponents of alternative viewpoints on many different counts, but three persistent internal criticisms stand out as particularly worthy of notice. Many, including Hartshorne, have rejected Whitehead's theory of forms (eternal objects) as too Platonic, preferring a more temporalistic understanding of the emergence of possibilities. The eternal objects are not permanent forms, somehow always subsisting, for they are only intermittently temporally instantiated. On the other hand, they are uncreated and to that extent an exception to Whitehead's ontological principle, which grounds all reasons in actualities.
Others question whether a theory of persons as series of momentary selves does justice to our experience of continuous, persistent selfidentity and the requirements of responsibility. But the theory can explain relative self-identity in terms of memory and anticipation, and questions whether absolute self-identity permits us to be radically constituted by our experience of others. As Hartshorne wryly observes, we cannot love our neighbors as ourselves if our relations to ourselves must be absolutely different from our relations to others. Nor does responsibility for past acts depend upon absolute self-identity. If officials can be held responsible for the actions of their predecessors, should not the same be true for momentary selves with respect to their predecessors?
Edward Pols, in the most thoroughgoing critique of Whitehead published to date, develops the objection also made by Paul Weiss that these actual occasions cannot do anything, that there are no real agents. This is true insofar as any action consists in the unity of intentional activity and causation, while in process theory this unity is split between two actualities: the first creates itself by its own intentional activity, and it only exerts causal influence as it is objectively appropriated by another. This simply means, however, that actions are inherently relational, necessarily involving the activity of the effect as well as the cause. Any theory vesting the action solely in one actuality as agent permits some causes to completely determine their effects, contrary to the postulate of universal creativity.
Bibliography: a. n. whitehead, Process and Reality (New York 1929); Adventures of Ideas (New York 1933); Science and the Modern World (New York 1925; repr. 1967). c. hartshorne, Creative Synthesis and Philosophic Method (La Salle, Ill. 1970); Whitehead's Philosophy: Selected Essays, 1935–1970 (Lincoln, Neb. 1972). i. leclerc, Whitehead's Metaphysics (New York 1958). w. a. christian, An Interpretation of Whitehead's Metaphysics (New Haven, Conn. 1959). d. w. sherburne, ed., A Key to Whitehead's Process and Reality (New York 1966). j. b. cobb, jr., A Christian Natural Theology (Philadelphia 1965); Beyond Dialogue: Toward a Mutual Transformation of Christianity and Buddhism (Philadelphia 1982). e. pols, Whitehead's Metaphysics: A Critical Examination of Process and Reality (Carbondale, Ill.1967). l. s. ford, Transforming Process Theism (Albany, N.Y.2000.) n. rescher, Process Metaphysics: An Introduction to Process Philosophy (Albany, N.Y. 1996). v. lowe, Alfred North Whitehead: The Man and His Work, 2 v. (Baltimore, Md. 1985,1990). t. e. hosinski, Stubborn Fact and Creative Advance: An Introduction to the Metaphysics of Alfred North Whitehead (Lanham, Md. 1993).
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