Here we have concluded the first division of Greek philosophy, and we have now to pass to the second period. The first period of Greek philosophy extended to Aristotle, to the attainment of a scientific form in which knowledge has reached the standing of free thought. Thus in Plato and Aristotle the result was the Idea; yet we saw in Plato the universal made the principle in a somewhat abstract way as the unmoved Idea; in Aristotle, on the other hand, thought in activity became absolutely concrete as the thought which thinks itself. The next essential, one which now is immediately before us, must be contained in that into which Philosophy under Plato and Aristotle had formed itself. This necessity is none other than the fact that the universal must now be proclaimed free for itself as the universality of the principle, so that the particular may be recognized through this universal; or the necessity of a systematic philosophy immediately enters in, what we formerly called one in accordance with the unity of the Notion. We may speak of the Platonic and Aristotelian systems, but they are not in the form of a system; for that it is requisite that one principle should be maintained and consistently carried through the particular. In the perfect complex of the conception of the universe as it is to Aristotle, where everything is in the highest form of scientific knowledge led back to what is speculative, however empiric may be his manner of setting to work, there certainly is one principle brought forward, and that a speculative one, though it is not brought forward as being one. The nature of the speculative has not been explicitly brought to consciousness as the Notion—as containing in itself the development of the manifold nature of the natural and spiritual universe, consequently it is not set forth as the universal, from which the particular was developed. Aristotle’s logic is really the opposite of this. He in great measure passes through a series of the living and the dead, makes them confront his objective, that is, conceiving thought, and grasps them in his understanding; each object is on its own account a conception which is laid open in its determinations, and yet he also brings these reflections together, and thereby is speculative. If even Plato on the whole proceeded in an empiric way, taking up this and that idea, each of which is in turn examined, with Aristotle this loose method of procedure appears still more clearly. In the Aristotelian teaching the Idea of the self-reflecting thought is thus grasped as the highest truth; but its realization, the knowledge of the natural and spiritual universe, constitutes outside of that Idea a long series of particular conceptions, which are external to one another, and in which a unifying principle, led through the particular, is wanting. The highest Idea with Aristotle consequently once more stands only as a particular in its own place and without being the principle of his whole philosophy. Hence the next necessity in Philosophy is that the whole extent of what is known must appear as one organization of the Notion; that in this way the manifold reality may be related to that Idea as the universal, and thereby determined. This is the standpoint which we find in this second period.
A systematic philosophy such as this becomes in the first place dogmatism, in antagonism to which, because of its one-sided character, scepticism immediately arises. In the same way the French call what is dogmatic systématique, and système that in which all the conceptions must consistently proceed from one determination; hence to them systématique is synonymous with one-sided. But the philosophies that ensue are one-sided, because in them it was only the necessity of one principle that was recognized, without their meanwhile developing from themselves, as might well have come to pass in and for itself, the Idea as the real universal, and thus comprehending the world in such a way that the content is only grasped as the determination of the self-reflective thought. Hence this principle stands up formally and abstractly, and the particular is not yet deduced from it, for the universal is only applied to the particular and the rules for this application sought out. In Aristotle the Idea is at least implicitly concrete, as the consciousness of the unity of subjective and objective, and therefore it is not one-sided. Should the Idea be truly concrete, the particular must be developed from it. The other relation would be the mere bringing of the particular under the universal, so that both should be mutually distinguished; in such a case the universal is only a formal principle, and such a philosophy is therefore one-sided. But the true difficulty is that the two endeavours, the development of the particular from the Idea, and the bringing of the particular under the universal, collide with one another. The manifestations of the physical and spiritual world must first, from their respective sides, be prepared for and worked into the Notion, so that the other sciences can form therefrom universal laws and principles. Then for the first time can speculative reason present itself in determinate thoughts, and bring perfectly to consciousness the inwardly existing connection between them. As dogmatic, however, those philosophies, it may be further said, are assertive likewise, because in such a method the principle is only asserted and is not truly proved. For a principle is demanded under which everything is subsumed; thus it is only pre-supposed as the first principle. Before this we have had abstract principles such as pure Being, but here the particular, with which begins the distinction from what is different, became posited as the purely negative. That necessity, on the other hand, makes for a universal which must likewise be in the particular, so that this should not be set aside, but should have its determinate character through the universal.
This demand for a universal, even though still unproved principle, is henceforth present to knowledge. What answers to this demand now appears in the world through the inward necessity of mind—not externally, but as being in conformity with the Notion. This necessity has produced the philosophy of the Stoics, Epicureans, New Academy, and Sceptics, which we have now to consider. If we have remained too long in the consideration of this period, we may now make amends for this protraction, for in the next period we may be brief.