ACADEMY, GREEK, or ACADEME, the name given to the philosophic school founded by Plato. The name is derived from a pleasure garden or gymnasium situated in the suburb of the Ceramicus on the river Cephissus about a mile to the north-west of Athens from the gate called Dipylum. It was said to have belonged to the ancient Attic hero Academus, who, when the Dioscuri invaded Attica to recover their sister Helen, carried off by Theseus, revealed the place where she was hidden. Out of gratitude the Lacedaemonians, who reverenced the Dioscuri, always spared the Academy during their invasions of the country. It was walled in by Hipparchus and was adorned with walks, groves, and fountains by Cimon (Plut. Cim. 13), who bequeathed it as a public pleasure ground to his fellow citizens. Subsequently the garden became the resort of Plato (q.v.) who had a small estate in the neighbourhood. Here he taught for nearly 5o years till his death in 348 B.C., and his followers continued to make it their headquarters. It was closed for teaching by Justinian in A.D. 529 along with the other pagan schools. Cicero borrowed the name for his villa near Puteoli, where he composed his dialogue, The Academic Questions.
The Platonic Academy (proper) lasted from the days of Plato to those of Cicero, and during its whole course there is traceable a distinct continuity of thought which justifies its examination as a real intellectual unit. On the other hand, this continuity of thought is by no means an identity. The Platonic doctrine was so far modified in the hands of successive scholarchs that the Academy has been divided into either two, three or five main sections (Sext. Empir. Pyrrh. Hyp. i. 22o). Finally, in the days of Philo, Antiochus and Cicero, the metaphysical dogmatism of Plato had been changed into an ethical syncretism which com bined elements from the Scepticism of Carneades and the doc trines of the Stoics; it was a change from a dogmatism which men found impossible to defend, to a probabilism which afforded a retreat from Scepticism and intellectual anarchy. Cicero rep resents at once the doctrine of the later Academy and the gen eral attitude of Roman society when he says, "My words do not proclaim the truth, like a Pythian priestess; but I conjecture what is probable, like a plain man ; and where, I ask, am I to search for anything more than verisimilitude?" And again: "The characteristic of the Academy is never to interpose one's judg ment, to approve what seems most probable, to compare together different opinions, to see what may be advanced on either side and to leave one's listeners free to judge without pretending to dogmatize." The passage from Sextus Empiricus, cited above, gives the gen eral view that there were three academies : the first, or Old, acad emy under Speusippus and Xenocrates; the second, or Middle, academy under Arcesilaus and Polemon ; the third, or New, acad emy under Carneades and Clitomachus. Sextus notices also the theory that there was a fourth, that of Philo of Larissa and Char midas, and a fifth, that of Antiochus. Diogenes Laertius says that Lacydes was the founder of the New Academy (i. 19, iv. 59). Cicero (de Orat. iii. 18, etc.) and Varro insist that there were only two academies, the Old and the New. Those who maintain that there is no justification for the five-fold division hold that the agnosticism of Carneades was really latent in Plato, and became prominent owing to the necessity of refuting the Stoic criterion.
The general tendency of the Academic thinkers was towards practical simplicity, a tendency due in large measure to the inferior intellectual capacity of Plato's immediate successors. Cicero (de Fin. v. 3) says generally of the Old Academy: "Their writings and method contain all liberal learning, all history, all polite dis course; and besides they embrace such a variety of arts that no one can undertake any noble career without their aid . . . In a word the Academy is, as it were, the workshop of every artist." It is true that these men turned to scientific investigation, but in so doing they escaped from high altitudes in which Plato thought, and tended to lay emphasis on the mundane side of philosophy.
Of Plato's originality and speculative power, of his poetry and enthusiasm they inherited nothing, "nor amid all the learning which has been profusely lavished upon investigating their tenets is there a single deduction calculated to elucidate distinctly the character of their progress or regression" (Archer Butler, Lect. on Anc. Phil. ii. 315).
The modification of Academic doctrine from Plato to Cicero may be indicated briefly under four heads.
(I) Plato's own theory of Ideas was not accepted even by Speusippus and Xenocrates. They argued that the Good cannot be the origin of things, inasmuch as Goodness is only found as an attribute of things. Therefore, the idea of Good must be second ary to some other more fundamental principle of existence. This unit Speusippus attempted to find in the Pythagorean number theory. From it he deduced three principles, one for numbers, one for magnitude, one for the soul. The Deity he conceived as that living force which rules all and resides everywhere. Xeno crates, though like Speusippus infected with Pythagoreanism, was the most faithful of Plato's successors. He distinguished three spheres, the sensible, the intelligible, and a third compounded of the two, to which correspond respectively, sense, intellect, and opinion (64a). Cicero notes, however, that both Speusippus and Xenocrates abandon the Socratic principle of hesitancy.
(2) Up to Arcesilaus, the Academy accepted the principle of finding a general unity in all things, by the aid of which a principle of certainty might be found. Arcesilaus, however, broke new ground by attacking the very possibility of certainty. Socrates had said, "This alone I know, that I know nothing." went farther and denied the possibility of even the Socratic mini mum of certainty : "I cannot know even whether I know or not." Thus from the dogmatism of the master the Academy plunged into the extremes of agnostic criticism.
(3) The next stage in the Academic succession was the moder ate scepticism of Carneades which owed its existence to his opposi tion to Chrysippus, the Stoic. To the Stoical theory of apprehensi ble (or knowable) presentation, by which they expressed a con viction of certainty arising from impressions so strong as to amount to real knowledge, he opposed the doctrine of inapprehen sible (or unknowable) presentation, which denied any necessary correspondence between perceptions and the objects perceived. He saved himself, however, from absolute scepticism by the doc trine of probability or verisimilitude, which may serve as a practi cal guide in life. Thus his criterion of imagination is that it must be credible, irrefutable, and attested by comparison with other im pressions ; it may be wrong, but for the person concerned it is valid. In ethics he was an avowed sceptic. During his official visit to Rome he gave public lectures, in which he successively proved and disproved with equal ease the existence of justice.
(4) In the last period we find a tendency not only to reconcile the internal divergences of the Academy itself, but also to connect it with parallel growths of thought. Philo of Larissa endeavours to show that Carneades was not opposed to Plato, and further that the apparent antagonism between Plato and Zeno was due to the fact that they were arguing from different points of view. From this syncretism emerged the prudent non-committal eclecticism of Cicero, the last product of Academic development.