This may be seen still more clearly by considering how this double nature shows itself in all that thinks in a clearer manner. We assert that all essences, as such, that all things that are by themselves, and that possess true existence, are located in the intelligible world. This happens not only because they always remain the same, while sense-objects are in a perpetual flow and change[13]--although, indeed, there are sense-objects (such as the stars[14]), that remain the same--but rather because they, by themselves, possess the perfection of their existence. The so-called primary "being" must possess an existence which is more than an adumbration of existence, and which is complete existence. Now existence is complete when its form is thought and life. Primary "being," therefore, will simultaneously contain thought, existence and life. Thus the existence of essence will imply that of intelligence; and that of intelligence, that of essence; so that thought is inseparable from existence, and is manifold instead of being one. That which is not manifold (the One), cannot, therefore, think. In the intelligible world, we find Man, and the thought of man, Horse and the thought of horse, the Just Man and the thought of the just man; everything in it is duality; even the unity within it is duality, and in it duality passes into unity. The First is neither all things that imply duality, nor any of them; it contains no duality whatever. THE FIRST, THEREFORE, BEING SUPRA-COGITATIVE, DOES NOT KNOW ITSELF. Elsewhere we shall study how duality issues from unity. Here we merely insist that as the One is superior to "being," it must also be superior to thought. It is, therefore, reasonable to insist that it does not know itself, that it does not contain anything to be known, because it is simple. Still less will it know other beings. It supplies them with something greater and more precious than knowledge of beings, since it is the Good of all beings; from it they derive what is more important (than mere cogitation), the faculty of identifying themselves with it so far as possible. SECOND ENNEAD, BOOK FIVE. Of the Aristotelian Distinction Between Actuality and Potentiality. QUESTIONS TO BE DISCUSSED.