Alfred North Whitehead, answered from the texts and cited to the page.
The final real things of which the world is composed are actual entities — drops of experience, each a unit of becoming that prehends its actual world and integrates it into a determinate satisfaction. There are no enduring substances behind the actual occasions; what there is is the actual occasions and the societies they form through inheritance of defining characteristics.12
Prehension is the technical generalization of "feeling" — the appropriation of a datum from the actual world into the becoming of a new occasion.3 The misplaced charge against this scheme is that it is panpsychism, the attribution of consciousness to atoms. Consciousness is no part of the categoreal scheme at the lower grades. Consciousness is a high-grade subjective form that arises only in complex hybrid societies — in the conscious operations of an animal body with a central nervous system, where conceptual feelings of contrast achieve a vividness sufficient to register as awareness.
The structural claim — that any actuality whatsoever appropriates data from its past and integrates them into a unified satisfaction — is what is asserted of every actual entity. That is not the attribution of mentality to electrons; it is the metaphysical generalization of the vector character of physical inheritance that physics itself has already discovered.4
In other words, an 'exterior thing' is either = one 'actual entity,' or is a 'society' with a 'defining characteristic. For the organic philosophy, these 'exterior things' (in the former sense) are the final concrete actualities. The individualized substance (of Locke) must ~ society of Be ac oc iis things,' stretching from the first 'thing' to the last 'thing.Process and Reality, pp. 88–89
There is also an enduring object formed by the inheritance from presiding occasion to presiding occasion. This endurance of the mind is only one more example of the general principle on which the body is constructed. This route of presiding occasions probably wanders from part to part of the brain, dissociated from the physical material | atoms.Process and Reality, p. 168
Each actual entity is 'divisible' in an indefinite number of ways, and each way of 'division' yields its definite quota of prehensions. A prehension reproduces in itself the general characteristics of an actual entity: it is referent to an external world, and in this sense will be said to have a 'vector character'; it involves emotion, and purpose, and valuation, and causation.Process and Reality, pp. 29–30
There can be no 'mere' togetherness of such abstractions. The result is that philosophical discussion is enmeshed in the fallacy of 'misplaced concreteness.Process and Reality, p. 28
The most-contested element of the system at the level of public reception. The "panpsychism" charge has dogged the philosophy since the 1930s. The recent panpsychism revival (Galen Strawson 2006, Philip Goff 2017) has reframed the situation: contemporary defenders of constitutive panpsychism find the categoreal scheme a serious resource, and the structural claim — that experience does not appear ex nihilo from a wholly non-experiential base — is now defended on independent grounds. David Ray Griffin's Unsnarling the World-Knot (1998) develops the Whiteheadian panpsychism explicitly. Christian's analytical reading (1959) emphasized that the categoreal claim is structural rather than psychological, and this remains the standard defense. The internal Sherburne fork — that the structural categories can be retained without the panpsychic gloss — is a live alternative reading.