So far our investigation has been analytical. We have seen Plotinus acquire, one after another, the elements out of which his system has still to be constructed. The first step was to separate spirit from matter. They are respectively distinguished as principles of union and of division. The bodies given to us in experience are a combination of the two, a dispersion of form over an infinitely extended, infinitely divisible, infinitely changeful substratum. Our own souls, which at first seemed so absolutely self-identical, present, on examination, a similarly composite character. A fresh analysis results in the separation of Nous or Reason from the lower functions of conscious life. And we infer by analogy that the soul in Nature bears the same relation to a transcendent objective Nous. Nous is essentially pure self-consciousness, and from this self-consciousness the world of Ideas is developed. Properly speaking, Ideas are the sole reality: sensible forms are an image of them impressed on matter through the agency of the world-soul. But Nous, or the totality of Ideas, though high, is not the highest. All that has hitherto occupied us, Nature, Soul, and Reason, is pervaded by a fundamental unity, without which nothing could exist. But Soul is not herself this unity, nor is Reason. Self-consciousness, even in its purest expression, involves a duality of object and subject. The notion of Being is distinct from the notion of oneness. The principle represented by the latter, as the cause of all things, must itself transcend existence. At the same time, it is revealed to us by the fact of our own personal identity. To be united with oneself is to be united with the One.