Plato’s philosophy had two stages through which it of necessity developed and worked its way up to a higher principle. The universal which is in reason had first to fall into two divisions opposed to each other in the most direct and unmitigated contradiction, in the independence of the personal consciousness which exists for itself: thus in the New Academy self-consciousness goes back into itself, and becomes a species of scepticism—the negative reason, which turns against all that is universal, and fails to find the unity of self-consciousness and the universal, coming accordingly to a standstill at that point. But, in the second place, the Neo-Platonists constitute the return, this unity of self-consciousness and the absolute essence; to them God is directly present in reason, reasoned knowledge itself is the Divine Spirit, and the content of this knowledge is the Being of God. Both of these we shall consider later.
Here we leave Plato, and we do so with regret. But seeing that we pass to his disciple, Aristotle, we fear that it behoves us to enter even more into detail, since he was one of the richest and deepest of all the scientific geniuses that have as yet appeared—a man whose like no later age has ever yet produced. Because we still possess so large a number of his works, the extent of the material at hand is proportionately greater; unfortunately, however, I cannot give to Aristotle the amount of attention that he deserves. For we shall have to confine ourselves to a general view of his philosophy, and simply remark on one particular phase of it, viz. in how far Aristotle in his philosophy carried out what in the Platonic principle had been begun, both in reference to the profundity of the ideas there contained, and to their expansion; no one is more comprehensive and speculative than he, although his methods are not systematic.
As regards the general character of Aristotle’s writings, he may be said to have extended his attention to the whole circle of human conceptions, to have penetrated all regions of the actual universal, and to have brought under the subjection of the Notion both their riches and their diversitude. For most of the philosophic sciences have to render thanks to him both for their characterization and first commencement. But although in this way Science throughout falls into a succession of intellectual determinations of determinate Notions, the Aristotelian philosophy still contains the profoundest speculative Notions. Aristotle proceeds in reference to the whole in the same way as in the individual case. But a general view of his philosophy does not give us the impression of its being in construction a self-systematized whole, of which the order and connection pertain likewise to the Notion; for the parts are empirically selected and placed together in such a way that each part is independently recognized as a determinate conception, without being taken into the connecting movement of the science. We need not try to demonstrate necessity from the standpoint of the philosophy of that time. But although Aristotle’s system does not appear to be developed in its parts from the Notion, and its parts are merely ranged side by side, they still form a totality of truly speculative philosophy.