The principle of universal relativity directly traverses Aristotle’s dictum, “A substance is not present in a subject” . . . . The philosophy of organism is mainly devoted to the task of making clear the notion of “being present in another entity.” (AN Whitehead)
“Insofar as Whitehead interpreted Aristotle’s theory of Entity [ousia] as if it were practically indistinguishable from a Lockean or even a Cartesian notion of substance, he was simply and radically mistaken. . . . [T]he (perhaps) Lockean notion of an anonymous stuff enduring without internal change beneath a transition of superficial qualities has nothing to do with Aristotle’s concept of Entity. Whitehead’s withering attack on the Lockean type of substance-philosophy proves nothing, therefore, against the Aristotelian concept of Entity.” (James Felt)
I think it can be shown that Whitehead’s equation of Aristotelian primary substance with Descartes’ definition rests upon a gross misunderstanding. It is, furthermore, a travesty to depict Aristotle’s substance as static and inert, hermetically sealed off from the causal efficacy of other entities and devoid of any internal becoming. (Leonard J. Eslick)