Reto Luzius Fetz is Professor of Philosophy at the Catholic University of Eichstaett, West Germany. He has recently published a book about Jean Piaget and is organizing an International Congress on Edith Stein for 1991.
The following article appeared in Process Studies, pp. 145-155, Vol. 9, Number 3, Fall, 1990. Process Studies is published quarterly by the Center for Process Studies, 1325 N. College Ave., Claremont, CA 91711. Used by permission. This material was prepared for Religion Online by Ted and Winnie Brock.
The author compares the thoughts of Aristotle and Whitehead concerning the self-development of living beings.
(Note: This essay was translated by James W Felt S.J., Professor of Philosophy at Santa Clara University, Santa Clara, CA 95053. Independently of Fetz’s book Felt published in Process Studies 14/4 (Winter 1985) an essay along some of the same lines: ‘Whitehead’s Misconception of ‘Substance’ in Aristotle.")
Whiteheadian Process Philosophy as Transformation of the Metaphysics of Spirit
Let us now take up in detail the process through which an [actual] entity becomes itself. In Whitehead’s view this process can mean the actualization of new and higher forms that were not yet "there" in the development of the world. As pure potentials these forms have their absolute ground in God. But how do they enter into the process of an ‘actual entity’ so as thereby to become ‘actual’?
Whitehead conceives the ‘mental pole’ as the "organ of novelty" (PR 391/516) Through the ‘conceptual’ prehensions attributed to it an actual entity’ feels the ideal of itself as its subjective aim’ whereby from these ‘conceptual feelings’ a ‘physical purpose’ results with which the ‘actual entity’ actualizes the previously held idea of itself From this it is clear that for Whitehead the ‘mental pole’ becomes the proper "place of forms"2 that Aristotle took to be the spiritual soul. And when Aristotle says that it is the forms "only potentially, not actually" (ibid), this also holds of the ‘mental pole’ insofar as the subjective aim’ prehended by it constitutes the possible final determination and not the already actualized self-identity of an ‘actual entity.’
Aristotle takes the spiritual soul to be the "place of the forms" because it possesses them through an act of knowledge. Such spiritual knowledge takes place through abstract, universal concepts. This spiritual activity 3 finds its resonance in Whitehead inasmuch as he calls the prehensions of the ‘mental pole’ ‘conceptual.’ But these conceptual’ prehensions are not necessarily conscious, and for that reason they cannot count as instances of knowledge if those are to be identified with instances of consciousness. Rather, their function is above all a purely ontological one, the appropriation of formal determinations to be actualized. Let us try to understand why Whitehead, by reason of his evolutionary thinking, opted for just this explanation, and what his ‘conceptual’ prehensions have in common with the "concepts" of the old metaphysics of spirit.
First of all, that Whitehead felt forced to deal with ‘conceptual’ prehensive events that are unconscious is, from an historical perspective, not so out of the way as it might appear. Judging from the history of the concept of spirit and of cognition, at least for all thinkers of a Platonic bent, specifically Aristotle himself,4 it becomes clear that the problem of consciousness by no means lies in the foreground. What characterizes spirit and thinking is primarily the range of their object, that is, the determinateness of something that stands out as something other than the perishable, changeable, and fortuitous things of the world; that, being universal and necessary, stands above time and place. What distinguishes spirit is its relation to the realm of the ideal. This directedness toward its object is so important for Aristotle that he treats the thinking subject and its act as "only by the way" present to themselves.5 That may turn out differently in Augustine, but even here the turn toward the ideal and eternal foundation of being marks the terminus of the "return to oneself."6 Descartes is the first to fashion the modern concept of consciousness that no longer stresses the field of the object but the self-presence of the subject.
Whitehead no longer takes consciousness to be something that constitutes a unique actuality, spirit; he certainly does not still regard consciousness as something fundamental, but more as simply a ‘subjective form’ of the more complex events of appropriation that are prehensions. In their complexity these consist  of ‘conceptual’ and ‘physical’ prehensions. In virtue of their objects, the prehensions that Whitehead calls ‘conceptual’ have all the characteristics traditionally ascribed to spiritual knowing; the very range of their objects is the ideal order. ‘Physical’ prehensions, on the other hand, describe the processes that take place within the reality of here and now. If the two Whiteheadian ‘poles,’ the ‘mental’ and the ‘physical,’ are regarded as the successors to the old concepts of spirit and matter -- which surely fits Whitehead’s meaning -- then Whitehead looms as the thinker who breaks with the modern era’s bias toward the problem of consciousness and who restores to its rightful place an analysis oriented toward the object, even to regarding such an analysis as alone decisive. What for Whitehead constitutes the ‘mental pole’ or "spirit" is in itself only the relationship to the ideal lying before it in the ‘conceptual’ prehensions. Consciousness is a supplementary factor that need not necessarily accompany the ‘conceptual’ or "spiritual" feelings, even if these in the end make consciousness possible.
But Whitehead’s ‘conceptual’ prehensions correspond in yet another respect to what is understood by "knowledge" in Aristotelianism. As Thomas Aquinas repeatedly mentions, "to know" means, as a first approximation, that a being is not just itself as this determinate actuality, but also is another, that is, by holding in itself other "forms," purely as forms, without at the same time itself having the real being that normally attaches to those forms.7 In this perspective, "knowing" expresses the possession of a multiplicity of forms that extends beyond the formal existence of the knower and includes forms that the knower in reality is not.
Now it is just this function that Whitehead assigns to the ‘mental pole’ and that he describes expressly in the ‘Category of Conceptual Reversion’ (PR 26/40,249/380). In virtue of this function, an ‘actual entity’ can include determinations of form that go beyond what is realized in the ‘physical pole’ of its initial phase. By means of such ‘conceptual’ prehensions the entity frames for itself a  self-image not of what it is but of what it ideally can be. It therefore holds true here, as well as in the above definition of knowledge, that the ‘conceptually’ felt realm of possibility of the ‘actual entity’ is wider than its ‘physical’ reality.
The Ideal Basis of Appetition
The ‘conceptually’ felt self-image provides the ‘actual entity’ with an aim that it endeavors ‘physically’ to realize. Whitehead’s ‘conceptual’ prehensions then are not an end in themselves but provide first of all for the adjustment and control of the ‘physical’ processes in view of the self that is to be actualized. Thereby the converse also holds, that Whitehead regards every appetition after an aim to be grounded in a ‘conceptual’ anticipation of the aim, even if it be unconscious. The ‘conceptually’ felt idea of the self is the final cause of its own process of self-creation. From the very beginning it belongs to the self-creating entity as its ‘subjective aim’ and is an essential element in its ‘satisfaction’ (PR 150/227).
For his theory of appetition Whitehead appeals to "idea" in the sense of Hegel (PR 167/254), to Leibniz (PR 32/47) and to the Eros of Plato (AI 354). In any case the conception is crucial for him that every appetition, as a basically rational process, must follow an idea that functions as an ideal and so is striven toward. Thus he also regards the ‘eternal objects’ as ultimately transtemporal possibilities for value that are called into actualization in the temporal process. Insofar as before their actualization in the world-process such possibilities for value can be felt only ‘conceptually,’ appetition proves to be for Whitehead the consequence of a "cognition" even though it be unconscious. In any case it is a determination through a form that the desiring entity does not ‘physically’ carry within itself.
In the tradition of Aristotle, Thomas Aquinas worked out precisely how every appetition is directed by a form as by its determining principle, whether this form really belong to a  being or be acquired in the act of knowing.8 Thus the kind of appetition peculiar to cognizant beings could be explained as an effect of their cognition. The appetition of spiritual beings is directed by the form acquired in spiritual knowing. If Whitehead’s doctrine of ‘conceptual feelings’ and the appetition resulting from them be regarded in this perspective it takes on the appearance of a generalization of this kind of appetition that is traditionally ascribed to spiritual beings. This generalization follows immediately when one bears in mind that Whitehead acknowledges a spiritual principle as belonging to every actual entity by reason of its mental pole. But the real ground of this generalization once again seems to us to lie in Whitehead’s thoroughly evolutionary and (in the Platonic sense) "idealistic" interpretation of actuality. Since he assigns to every actual entity the capacity of actualizing within the process of being itself a more complex form than that provided in the ‘physical pole’ of its initial phase, the entity must first of all ‘conceptually’ feel this unrealized form as an idea if it is to be determined by it as by a final cause.
If with Whitehead one conceives the process of actualization to be a creative advance, then it makes sense that he posits ‘conceptual valuation’ of the datum as the basic function of the ‘mental pole,’ prior to ‘conceptual reversion’ (PR 26/39, 248/379). For the emergence of new forms not only requires the ‘mental pole’ as the "organ of novelty." It requires it also to mediate between the newly arising formal determinations and the old forms already realized in the ‘physical pole.’ Such a mediation is possible only when the ‘physical’ datum is ‘conceptually’ prehended so as to be synthesized with the potentialities that transcend the datum. Thus the creative advance, taken as a synthesis between the "old" and the "new," must first of all be envisioned ‘conceptually’ if, as a consequence of this mediation, it is to be realized ‘physically.’ Hence Whitehead conceives the integration of the ‘physical’ datum to be realized through the ‘conceptual valuations’ that adjust the datum to the envisioned ‘subjective aim.’ In this way  Whitehead bestows subjectivity and finality upon all instances of process generally, so that in this perspective the question about their higher development is logically reduced to the question of how much they have ‘conceptually’ acquired of this formal causality. That from this ideal basis Whitehead was finally able to account for even the higher forms of experience -- the emergence of consciousness, of the recognition of truth, and of art -- proves the coherence and wide applicability of his theory.
Thus Whitehead sets about interpreting reality as a creative process, and does it with the conceptual tools of the classical metaphysics of spirit that he has fundamentally reinterpreted and generalized. By reason of its ‘mental pole’ every actual entity is spirit and performs spiritual activities that become autonomous in the more highly developed entities, but that are basically found in every actual entity. Thus the dividing line that traditionally separated human beings, as the only living beings endowed with spirit, from the unintelligent creatures of nature turns out in principle to be abolished. The process of every single being is determined by spirit.
It is worth noting here that in the Christian metaphysics of creation too, to which Thomas Aquinas can once again serve as an example, the process of nature is regarded as ultimately determined by spirit and by cognition in virtue of its fundamental goal-directedness.9 But in this tradition it is exclusively the creative spirit of God that as First Cause is operative in creatures and gives direction to their becoming, instead of a spiritual principle belonging to the natural beings themselves. For Whitehead, on the other hand, every creature itself becomes the spiritual subject of its own process of creation. It does not participate as a secondary cause in the spirit of God, but is itself the participating spirit. In consequence of Whitehead’s shift in emphasis on the creative process, every creature must be regarded as autonomously directing its own self-creation. It freely receives from God, and it itself actualizes. the possibility of its own self-identity; it does not carry out a finality imposed upon it (PR 244-5/374-5). 
Knowledge and Real Becoming
Thomas Aquinas, who conceives knowledge as the possession of additional forms, puts these on an equal footing with the forms of other beings. This is a consequence of the Aristotelian solution to the problem of form, according to which all forms are basically the forms of primary beings and are encountered as such in knowledge insofar as knowledge is directed to objective reality. For Aristotle as for Thomas this reality is primarily something in the world. Hence "knowledge" above all means "abstraction" of the forms of these things in the world from matter and from its individuating conditions, so as to possess them in their universality. From this relation to what is material it follows that intellectual and sensitive knowledge must be combined, whereby the latter for its part continually bases itself on material processes and continues them. Here, then, material processes, as well as sensitive and mental knowing, are in principle thought of as united in one event -- insofar as the natural science of those days allowed the event to be thought of in that way.10
This anchoring of knowledge in the processes occurring between beings, characteristic as it is of an Aristotelian sort of empirical realism, recurs with added emphasis in Whitehead. He wants to keep to "the old principle" (PR 248/379) that mentality originates from sensitive experience, and therefore he grounds his ‘conceptual’ prehensions in ‘physical’ ones. He generalizes this principle: according to the ‘Category of Conceptual Valuation,’ there is derived from every ‘physical’ prehension a ‘conceptual’ one that only after a complex integration goes on to play a conscious role in the knowing process. According to the ‘Category of Conceptual Reversion’ the ‘mental pole’ can, it is true, acquire more formal determinations than are ‘physically’ provided for it. But even here Whitehead sticks  to his realism, for he grounds this surplus of forms in the actual entity’s ‘hybrid,’ and so once again real, prehension of God (PR 246/317).
Whitehead attributes the principle of the origination of conceptual activity from the physical to Hume (PR 250/382). but his criticism of flume’s subjectivism is determinative for his own realism. Here we have to keep in mind the starting point of Whitehead’s philosophy, the ‘reformed subjectivist principle.’ By this principle, what we are confronted with in experience is real objects to which the subject must stand in equally real relations. Whitehead wants to ground his realism through a new ontology. The fundamental categories of his organic philosophy, and especially the key category of prehension, are intended to reproduce on a purely ontological plane the experiential situation as it presents itself to natural awareness as Whitehead finds it depicted by Locke.
In this regard Whitehead deliberately directs his sharpest polemic against the substance-quality model and thereby against the concept of substance found in Aristotle’s Categories, according to which a [primary] entity can not be in another as in its subject. For Whitehead, on the contrary, an [actual] entity has to be regarded as present in another so as to make possible the knowledge of the first by the sound (PR 50/79). This being-in-another, that makes knowledge possible without necessarily leading to it, becomes for Whitehead the fundamental intelligible structure of all actuality whatsoever. The radicality of Whitehead’s initial position is best seen if we go back, for comparison, to the essential definition of knowledge given by Thomas Aquinas. What is there set down as the structural characteristic peculiar to cognizant beings, namely to be able interiorly to be-the-other as well as themselves, for Whitehead is made into a general ontology. Whereas Thomas (Sum. Theol. I, 14, 1), along with Aristotle (De An. III, 8,431b21), says of the spiritual soul (and only of it) that by range of  its knowledge it is, "in a way, all things," so Whitehead declares that every actual entity is "a system of all things" (PR 36/53; see also 50/79),
If one takes the grounding of knowledge in the interrelations of real events and structures as an essential characteristic of Aristotelian realism, Whitehead turns out to be the Aristotelian willing to accept all the consequences of this seminal idea in an ontology. For him, as for no realist before him, the theory of knowledge is transformed into, and underpins, an ontology. The unbridgeable chasm that had existed since Descartes between spirit and the world of bodies, between the functions of consciousness and material processes, is eliminated through a unitary ‘theory of prehensions.’ In this theory the ‘physical’ and ‘conceptual’ prehensions are so conceived that they can complement and freely give rise to each other (PR 246/376). But going beyond Descartes, one has to ask whether Whitehead, with his categoreal scheme that equally includes the ‘physical’ and the ‘mental,’ has not closed a gap found as far back as Aristotle between theory of nature and theory of knowledge.
When Whitehead attacks the concept of substance in Aristotle’s Categories he directs his polemic especially against the ‘simple location’ of natural entities, according to which they exist merely at their particular places and without internal relations to one another. True, this criticism is aimed directly at the materialistic mechanism that Whitehead took to be the consequence of an erroneous conception of substance according to which there exist only autonomous, isolated bits of matter. But Aristotle seems also to be a target of Whitehead’s criticism of ‘simple location’ insofar as Aristotle’s theory of place as the boundary of the surface of a body appears to support such a theory (Physics IV, 4, 212a5). According to Aristotle every body excludes every other body from its place, so that only it exists in that place without including within itself others (212b25). This is connected with Aristotle’s idea that material processes occur mainly through touch, through contact with external bodies. The lack of such contact  in the higher forms of sense perception finally forces Aristotle and Thomas Aquinas to give up their principle that sensitive-spiritual knowledge is always grounded in corresponding real processes.11
In these questions there is doubtless at work in Aristotle’s mind a concept of bodies that is pragmatically oriented to the world of things, a concept that Whitehead, from the higher vantage point afforded by modem scientific knowledge, is able to dismiss. But if one examines Aristotle’s doctrine on natural processes more closely, the picture changes. For wherever Aristotle allows his own proper concepts and insights, instead of the common concepts of things, to dominate his analysis, he too overcomes ‘simple location’ through a concept of dynamic immanence. So the question arises, in what relation does Whitehead’s process thought stand to the genuine starting principles of Aristotle’s doctrine?
Natural Process as Being in Another
It is well known that Aristotle analyses the processes of nature with the paired concepts potentiality-actuality (Phys. III, 1-3). He conceives such a process as the actualization of a state of potentiality in the object of the process, an actualization that comes about through the influence of the cause of the process (201a10; 202a14). Thus the cause must for its part exhibit the potentiality to cause the process. A state of potentiality belongs therefore to the cause as well as to the object of the process. In the one case it is the potentiality to cause something, in the other the potentiality for a definite actualization to be achieved. But the actualization of the object of the process is itself grounded in the actualization of the activity of the cause of the process. So at the end of this analysis we are faced with the paradox that the actualization of the cause of the process goes on in the object of the process, indeed has to be thought identical with it (202a1 3-21). 
Aristotle himself acknowledges the seemingly puzzling nature of this state of affairs. It seems puzzling and out of the ordinary to us because it exactly traverses the ordinary conception according to which a bodily thing is only actual in its own place. Aristotle lays out the difficulties that the ordinary understanding places in the way of his conception: the actualization of the cause of the process seems to be distinct from that of the object of the process, for the one is an effecting, the other a being effected. But if one wants to think of them as two actualizations or two processes, and tries to divide them up between the cause and the object of the process, only then do difficulties really arise and the process of becoming loses its coherence (202a21-35).
So it must be correct after all that the actualization of the cause of the process and of the object of the process is one, just as their process is one. Effecting and being effected can be conceptually distinguished, but in fact they are one in the event (202b11). And now Aristotle explicitly declares that it is by no means absurd to situate the actualization of the cause of the process in the object of the process, to suppose that the actualization of the one is the actualization in the other (202b5). The actuality of the one corresponds to the potentiality of the other, so as to make the actualization of this potentiality a unity (202b8).
Why do we think this important? For one thing because Aristotle here makes clear that conceptual and logical distinctions, like those of his Categories, should not be permitted to conceal real relationships. Thus Aristotle here consistently overcomes the idea of ‘simple location’ and of purely extrinsic mutual activity, so as to conceive of natural beings as truly immanent in each other. What Whitehead conceives as the objectification  of an actual entity appears in the Aristotelian conception of process as anticipated in the actualization of one being in another.
Aristotle thinks of such processes as efficient, arising from the cause of the process and terminating in the object of the process. The Scholastics coined a phrase for this: actio transiens. When Whitehead speaks of efficacious processes as transitions (PR 150/227; 210/320) he is using the very same word to express the same state of affairs, even if no direct historical connection of the usage can be demonstrated.
If Whitehead and Aristotle are at one on this decisive point, Whitehead nevertheless puts a great deal more weight on it. For he raises this dynamic immanence to the level of his essential principles and makes his ‘actual entities’ altogether determined by it. In accord with his ‘principle of process’ (PR 23/34), he wants the being of an actual entity to be understood in terms of its becoming, without which it would have no existence. Again, according to the explication of the ‘ontological principle’ (PR 24/36), an ‘actual entity’ constitutionally points back to other actual entities that ground it. Finally, by the ‘principle of relativity’ (PR 22/33) the possibility of itself entering into the process constituting other actual entities is declared to be the one universal characteristic of every being.
One cannot, however, so readily assert of Aristotle that in his concept of process he consistently remains true to the immanence that he therein supposes one being to have in another -- as his theory of place gives witness. Typically he exploits this fundamental principle of immanence only when he is reflecting on a natural being as it relates to its becoming, as he does particularly when considering the causal principle according to which every natural being in a state of becoming refers back to a cause of its becoming (Phys. VIII, 4). The principle emerges again in the analysis of the efficacious power  of an entity, a power that Aristotle conceives as the principle of change in another, and correspondingly also as a potentiality belonging to the object of change, the principle of its capacity to be acted upon by another.
Does it follow from this that Aristotle does not consistently bring to its full expression this immanence and interdependence of natural beings precisely because he does not radically enough attend to their process character -- because he does not thoroughly grasp them as process, as Whitehead does? If so, then this must point to the decisive change in the concept of nature by which Whitehead goes beyond Aristotle.
That Aristotle supposedly underestimated the process character of a natural being is a risky opinion considering that he takes becoming to be the hallmark of natural beings (Phys. II, 1; III, 1). For him, too, process is constitutive for the entity itself; he explicitly cites generation as the process constitutive for the entity, and distinguishes it from the processes that effect merely accidental changes in the entity (De Gen. et Corr. I ,4-5),
Now it seems to us that Aristotle’s concept of generation is far less radically thought through than the constitution of a being through its own becoming as expressed in Whitehead’s ‘principle of process.’ For generation marks for Aristotle the beginning of an entity; it is the process that brings an entity into the world with its own character. Thus this concept tends to encourage the idea that once the entity is constituted it is thereafter simply "there," experiencing or exercising purely accidental processes until finally it once again perishes. This illustrates the idea, rejected by Whitehead, of an undifferentiated endurance, of the persistence through time of the entity. Whitehead wants to circumvent this idea with his ‘epochal’ theory of time, according to which an actual entity exists only as long as the timespan of the becoming that constitutes it (PR 308/469f). In Aristotelian language, Whitehead so identifies a being with its process of becoming that he allows it to count as actual solely within the process but not  as a being that, once generated, would simply continue to exist. The question now is whether we can further develop this clearly apparent difference and reduce it to fundamental concepts.
The Identification of Being and Process
When Aristotle assigns an exclusive place to every natural being and excludes all others from that place, his concept of a natural being as material is predominantly at work. What fixes a natural being at its place is its matter, with matter’s quantitative, dimensional determinations. This concept recurs in Thomas Aquinas inasmuch as he takes matter determined by quantity to be a material being’s principle of individuation whereby it can be grasped in its individual "thereness."12 On the other hand for Aristotle it is once again matter that gives a natural being its potentiality to ground newly arising beings by enabling it to take on endlessly different forms.13 What Whitehead demands with his ‘principle of relativity’ is furnished in Aristotle by matter as the ground of fundamental changeableness and hence of the process character of natural beings.
Thus Aristotelian matter as principle of individuation is at the same time the principle by reason of which one being can become another.’4 The difference from Whitehead seems to us to lie in this, that for Aristotle matter is an ultimate that always signifies the possibility of change and of process without of itself being something in process. Aristotle thinks of matter as something passive, stable, that does not of itself transform itself into something else. Hence every process occurring within an object requires the efficacy of another cause, and matter altogether requires form, in order to produce something actual and efficacious.
Thus we once again run into the crucial difference,  that Whitehead acknowledges no such passive matter that is simply at hand awaiting transformation and actuation, but only an act of becoming that individuates itself in particular beings. For him the boundary concept that ultimately characterizes natural actuality is no longer matter but creativity.
One can gather from this why the dynamic immanence of one entity in another is much more radically conceived by Whitehead than it is by Aristotle. Whitehead’s ‘principle of process,’ his ‘ontological principle,’ and his ‘principle of relativity’ can be regarded as a consistent continuation of Aristotle’s doctrine on becoming as it looks when one suppresses the notion of a passive and static Aristotelian matter. Since Whitehead no longer acknowledges any such matter, there is for him no endurance opposed to process. The actual entity is only process, the outcome of its process, and the beginning of new processes.
Whitehead, like Aristotle, takes process to be the actualization of one thing in another. The actualized Other, by its very constitution, points back to its efficient cause, for it contains an internal relationship to it. Whitehead gives expression to this in his ‘ontological principle’ insofar as he conceives it as the ‘principle of efficient causality’ (PR 24/36).
The analogy with Aristotle’s causal principle is obvious, and it is just as evident why this principle achieves a new finality with Whitehead. For Aristotle the actualizing of matter, not matter itself, points back to another efficient cause. Matter as a principle of receptivity is simply there, without itself displaying any actual internal relationship to another. Such a relationship belongs to matter, or rather to the being constituted by the matter, primarily through the processes taking place within the being, and the relation lasts as actual only as long as such a process continues. Actualized matter as such persists in itself without relations. It is the locus of new potential relations but is not itself the bearer of actual relations. If one thinks of a thing consisting of such matter, without the processes that constitute the thing, one immediately thinks  of the notion of ‘simple location’ just as Aristotle described in his concept of place.
For Whitehead, the actual entity is never simply actualized matter, it is always its own process by which it constitutes itself. It is thereby manifest in those relationships that are given with that process and that are intrinsic to it, just as its process is intrinsic to it and constitutes its essence. Thus for Whitehead the causal principle, that for Aristotle is only a principle of becoming and not a principle of being, is raised to the rank of a principle that accounts for the entity’s constitution. The principle has become ontological. The being [Sein] of a natural entity points, as such, to other actual entities causally efficacious within it, since what it is, is just this process grounded in others and not an inert matter within which process takes place.
The abolition of such a matter naturally casts a new light on process itself. When Aristotle conceives process as the actualization of the cause of the process within the object of the process, both the cause and the object of the process are presumed to be already given. In Aristotle’s theory, the categories of action and passion in terms of which the process from the cause to its object is described, are classified as "accidents," determinations that advene to the being and that as such are first listed after the categories of quantity and quality (Cat. 4, 1b25).
That according to Aristotle it is ultimately always matter that is treated as already given, is especially evident in procreation. For here it would of course be absurd to presuppose the being that is the object of the process, since it only arises from that process in the first place. But even here Aristotle presupposes a substrate through which and in which the procreative process takes place. This substrate is a "primary matter," already present under the perishing form, that passes to a new form of being through the influence of the efficient cause (Phys. I,9, 192a31).
Whitehead drops matter, in the sense of that sort of substrate always lying at hand, and so process no longer has the same status as it did for Aristotle. Process no longer takes place  within matter but stands as it were on its own and makes up the entirety of its subjects, instead of presupposing a substrate out of which it fashions its subjects. Thus process itself takes on the character of something concrete; it is the very beings constituted by it. True, this conclusion is not novel, for it amounts to the assertion, familiar enough by now, that Whitehead identifies entity with process. But it throws the proper light on Whitehead’s key category of prehension. This proves to be the category by means of which Whitehead thus identifies process, conceived without a material substrate, with the [actual] entity itself.
How similar Whitehead thought [actual] entity and prehension to be is clear especially in the similarity of their structure. According to Whitehead a prehension "reproduces" in itself the general characteristics of an ‘actual entity.’ As an element of an [actual] entity it is structured exactly as is the entity as a whole. Thus prehensions are the most concrete elements that the analysis of an [actual] entity reveals. They individually fulfill what the ‘ontological principle.’ the ‘principle of process,’ and the ‘principle of relativity’ require for an [actual] entity generally (PR 19/28). Only because Whitehead conceives an [actual] entity in terms of its prehensions does he succeed in living up to his claim of giving relation dominance over the Aristotelian category of quality (PR xiii/ix).
Whitehead emphasizes often enough that [actual] entities exist neither before nor apart from their prehensions. Without the prehensions that compose it an [actual] entity dissolves into nothing; it is nothing other than its prehensions. When Whitehead speaks of an [actual] entity as ‘superject,’ he means by this neologism that the [actual] entity really arises out of its prehensions instead of independently preceding them. Often it almost seems as if Whitehead gives precedence to prehension over [actual] entity, as when he drops the remark that a prehension could be taken for a [complete] actuality even though it ultimately makes up only an aspect of the [actual] entity  as a subordinate element of its totality. A further indication of the "substantial" role of prehensions lies ultimately in this, that all the qualities of natural reality that Aristotle takes to be grounded in the matter of a natural being are for Whitehead constituted through prehensions. That is true particularly of those qualities connected with nature as a space-time continuum. For Whitehead they have their real ground in the vector-character of physical prehensions, and no longer, as for Aristotle, in the quantitative determinations of a pre-given matter.
The replacement of Aristotelian "matter" with Whiteheadian ‘creativity,’ and the consequent precedence given by the key concept of prehension to the relational over every merely qualitative determination of a being, undoubtedly allows the Whiteheadian [actual] entity to embody process in a more radical sense than does being as conceived by Aristotle. Yet if one compares Aristotle’s analysis of the forms of process with the process of prehension, one can very well ask whether the former would not lead to the latter if it were thought through to the end. Both thinkers begin with a fundamentally analogous concept of entity, and what dominates in the genuine Aristotelian concept of entity is ultimately not matter but the form that gives the entity its determination. Aristotle distinguishes between the processes that proceed from a being’s efficacious power to act on another, and those "natural" processes in which a being actualizes its "nature," that is, its potentiality for being itself in accordance with its form (Met. IX, 8, 1049b5-l0). Whitehead hits upon a similar distinction when he contrasts ‘transitions’ with the intrinsic process of the concrescence (PR 210/320). Thus in the category of prehension we seem to have before us an accurate synthesis of these two forms of process distinguished by Aristotle. Whitehead describes prehension as the process that arises out of given entities and aims at a newly arising entity (PR 151/228). Insofar as the given entities thus function as efficacious causes, prehension is identical with the process of efficient causality described by  Aristotle -- in Scholastic terms, with moveri ab alio. But insofar as the prehension is directed to its own aim by the newly arising entity, it corresponds to those processes that Aristotle called "natural," in which "nature" acts as both source and aim of its own activity. In that way prehension comprises that highest form of natural process ascribed by Aristotle to living beings and which Scholasticism conceived as motus sui, as actualization of itself through itself.15 Whitehead matches Aristotle in so many main points not least because both are mainly concerned with living beings and their self-development.
1This a translation of section 3.2 of Fetz, Whitehead: Prozessdenken und Substanznietaphysik (Freiburg/Munchen, Verlag Karl Alber: 1981). A translation of Section 3.1 was published in a previous issue of this journal as "Aristotelian and Whiteheadian Conceptions of Actuality: I." The author has reviewed and corrected the draft of this translation, for which the translator is grateful.
2De An. III, 4 429a27-29.
3Translotor‘s note: Page breaks in the original text are thus indicated in square brackets.
4See De An. III, 4-8; Nic. Eth. X, 7-8.
5Met. XII, 9 1074 b 35.
6See De Trinitate IX, VI, 9 (PL 42, 965f.).
7See S. T. 1, 14, l, etc.
8See S.C. G. II, 47; S. T., 141,26, 1.
9See S.C. G. III, 24; S. T. I-II, 26, 1; 27, 2 ad 3.
10Thomas Aquinas still leaves unresolved the problem of how the higher forms of sense knowledge, especially that of vision, can be grounded in a material process. Compare, perhaps, S. T. I, 78, 3, on the external senses.
11See n. 10 above.
12See Met. V. 6, 1016b32, and Thomas’s commentary on it; also S. T. III, 77, 2.
13Phys. I, 9; De Gen. et Corr. I, 3.
14Phys. 1, 9; De Gen. et Corr. I, 3.
15See De An. II, I. 412a14; S. T. I, 18, 1; etc.
List of Abbreviations
List of Abbreviations
Referring to works of Aristotle:
Cat -- Categories
De An -- De Anima (On the Soul)
De Gen. et Corr. -- De Generatione et Corruptione (On Generation and Corruption)
Met -- Metaphysics
Nic. Eth. -- Nicomochean Ethics
Phys. -- Physics
Referring to works of Thomas Aquinas:
S.C.G. -- Summa contra Gentiles (Summa against Unbelievers)
S.T. -- Summa Theologiae (Summa of Theology)