Intelligence exists (as intelligence) because it thinks existence. Existence exists (as existence) because, on being thought, it makes intelligence exist and thinks.[229] There must therefore exist something else which makes intelligence think, and existence exist, and which consequently is their common principle. In existence they are contemporaneous and substantial, and can never fail each other. As intelligence and existence constitute a duality, their common principle in this consubstantial unity that they form, and which is simultaneously existence and intelligence, the thinking subject and the object thought; intelligence as thinking subject, and existence as object thought; for thought simultaneously implies difference and identity. THE SIX CATEGORIES FROM WHICH ALL THINGS ARE DERIVED. The first principles, therefore, are existence and intelligence, identity and difference, movement and rest.[230] Rest is the condition of identity; movement is the condition of thought, since the latter presupposes the differences of the thinking subject and of the object thought, and because it is silent if reduced to unity. The elements of thought (subject and object) must thus stand in the relation of differences, but also in that of unity, because they form a consubstantial unity, and because there is a common element in all that is derived therefrom. Besides, here difference is nothing else than distinction. The plurality formed by elements of thought constitutes quantity and number;[231] and the characteristic of every element, quality.[232] From these first principles (the categories, that are the genera of being) all things are derived. THE SOUL AS NUMBER CONNECTED WITH INTELLIGENCE. 5. Thus the human soul is full of this divinity (of Intelligence); she is connected therewith by these (categories), unless the soul (purposely) withdraws from (that intelligence). The Soul approaches Intelligence, and thus having been unified, the Soul wonders, 'Who has begotten this unity?' It must be He who is simple, who is prior to all multiplicity, who imparts to Intelligence its existence and manifoldness, and who consequently produces number. Number, indeed, is not something primitive; for the One is prior to the "pair." The latter ranks only second, being begotten and defined by unity, by itself being indefinite. As soon as it is defined, it is a number in so far as it is a "being"; for these are the grounds on which the Soul also is a number.[233] THOUGHT IS ACTUALIZATION OF SIGHT, AND BOTH FORM BUT ONE THING.