In that vulgar conception of actuality which mistakes for it what is palpable and directly obvious to the senses, we must seek the ground of a wide-spread prejudice about the relation of the philosophy of Aristotle to that of Plato. Popular opinion makes the difference to be as follows. While Plato recognises the idea and only the idea as the truth, Aristotle, rejecting the idea, keeps to what is actual, and is on that account to be considered the founder and chief of empiricism. On this it may be remarked: that although actuality certainly is the principle of the Aristotelian philosophy, it is not the vulgar actuality of what is immediately at hand, but the idea as actuality. Where then lies the controversy of Aristotle against Plato? It lies in this. Aristotle calls the Platonic idea a mere δίναμις, and establishes in opposition to Plato that the idea, which both equally recognise to be the only truth, is essentially to be viewed as an ἐνέργεια, in other words, as the inward which is quite to the fore, or as the unity of inner and outer, or as actuality, in the emphatic sense here given to the word. 143.] Such a concrete category as Actuality includes the characteristics aforesaid and their difference, and is therefore also the development of them, in such a way that, as it has them, they are at the same time plainly understood to be a show, to be assumed or imposed (§ 141). (α) Viewed as an identity in general, Actuality is first of all Possibility--the reflection-into-self which, as in contrast with the concrete unity of the actual, is taken and made an abstract and unessential essentiality. Possibility is what is essential to reality, but in such a way that it is at the same time only a possibility. It was probably the import of Possibility which induced Kant to regard it along with necessity and actuality as Modalities, 'since these categories do not in the least increase the notion as object, but only express its relation to the faculty of knowledge.' For Possibility is really the bare abstraction of reflection-into-self,--what was formerly called the Inward, only that it is now taken to mean the external inward, lifted out of reality and with the being of a mere supposition, and is thus, sure enough, supposed only as a bare modality, an abstraction which comes short, and, in more concrete terms, belongs only to subjective thought. It is otherwise with Actuality and Necessity. They are anything but a mere sort and mode for something else: in fact the very reverse of that. If they are supposed, it is as the concrete, not merely supposititious, but intrinsically complete.