In the old Academy, we lose the presence of inventive genius; with few exceptions we find here no movements of progress, but rather a gradual retrogression of the Platonic philosophizing. After the death of Plato, Speusippus, his nephew and disciple, held the chair of his master in the Academy during eight years. He was succeeded by Xenocrates, after whom we meet with Polemo, Crates, and Crantor. It was a time in which schools for high culture were established, and the older teacher yielded to his younger successor the post of instruction. The general characteristics of the old Academy, so far as can be gathered from the scanty accounts, were great attention to learning, the prevalence of Pythagorean elements, especially the doctrine of numbers, and lastly, the reception of fantastic and demonological notions, among which the worship of the stars played a part. The prevalence of the Pythagorean doctrine of numbers in the later instructions of the Academy, gave to mathematical sciences, particularly arithmetic and astronomy, a high place, and at the same time assigned to the doctrine of ideas a much lower position than Plato had given it. Subsequently, the attempt was made to get back to the unadulterated doctrine of Plato. Crantor is said to be the first editor of the Platonic writings.

As Plato was the only true Socraticist, so was Aristotle the only genuine disciple of Plato, though often abused by his fellow-disciples as unfaithful to his master’s principles.

We pass on at once to him, without stopping now to inquire into his relation to Plato, or the advance which he made beyond his predecessor, since these points will come up before us in the exhibition of the Aristotelian philosophy. (See § XVI: III. 1.)