With Aristotle δύναμις does not therefore mean force (for force is really an imperfect aspect of form), but rather capacity which is not even undetermined possibility; ἐνέργεια is, on the other hand, pure, spontaneous activity. These definitions were of importance throughout all the middle ages. Thus, according to Aristotle, the essentially absolute substance has potentiality and actuality, form and matter, not separated from one another; for the true objective has most certainly also activity in itself, just as the true subjective has also potentiality. From this definition we now see clearly the sort of opposition in which the Idea of Aristotle stands to that of Plato, for although the Idea of Plato is in itself essentially concrete and determined, Aristotle goes further. In so far, namely, as the Idea is determined in itself, the relation of the moments in it can be more closely specified, and this relation of the moments to each other is to be conceived of as nothing other than activity. It is easy for us to have a consciousness of what is deficient in the universal, that is, of that which is implicit only. The universal, in that it is the universal, has as yet no reality, for because implicitude is inert, the activity of realization is not yet posited therein. Reason, laws, etc., are in this way abstract, but the rational, as realizing itself, we recognize to be necessary, and therefore we take such universal laws but little into account. Now the standpoint of Plato is in the universal; what he does is to express Being rather as the objective, the Good, the end, the universal. To this, however, the principle of living subjectivity, as the moment of reality, seems to be lacking, or it appears at least to be put in the background. This negative principle seems indeed not to be directly expressed in Plato, but it is essentially contained in his definition of the Absolute as the unity of opposites; for this unity is essentially a negative unity of those opposites, which abrogates their being-another, their opposition, and leads them back into itself. But with Aristotle this negativity, this active efficacy, is expressly characterized as energy; in that it breaks up itself—this independence—abrogating unity, and positing separation; for, as Aristotle says (Metaph. VII. 13), “actuality separates.” The Platonic Idea, on the other hand, is rather that abrogation of opposites, where one of the opposites is itself unity. While, therefore, with Plato the main consideration is the affirmative principle, the Idea as only abstractly identical with itself, in Aristotle there is added and made conspicuous the moment of negativity, not as change, nor yet as nullity, but as difference or determination. The principle of individualization, not in the sense of a casual and merely particular subjectivity, but in that of pure subjectivity, is peculiar to Aristotle. Aristotle thus also makes the