When Plato returned to the Academy from Syracuse, there was a hint of rebellion in the air. A new student had appeared while Plato was away, a stranger from the north: Aristotle of Stagira. The son of a physician, with ties to the royal house of Macedonia, he was a child prodigy.[1] He had strong opinions, and a commitment to the here-and-now rather than the distant World of Forms. He quickly began working out an alternative account of reality and knowledge, based on the immediate environment and one’s experience of it. Aristotle in fact was joining a chorus of those who rejected idealism and rationalism. Plato’s worldview was under attack.
For about two decades, Plato had been producing dialogues developing his own theories for a presumably friendly audience in the Academy and the Greek world generally. He had introduced the Theory of Forms to support a realistic value theory. Whereas the sophists, or at least many of them, had raised the possibility that human value systems were mere inventions designed to support the status quo, or perhaps to uphold the worldview of the rulers, Plato had been working to show that values such as virtues and ideals were real entities, existing independently of human subjects. Thus Justice, Courage, and Goodness, for instance, were not human inventions, but human discoveries of eternal values that transcended the here and now, offering insights into the nature of things.
Plato put his value theory into the mouth of his character Socrates, who now graduated from being a perennial seeker of wisdom who professed to have no special knowledge to being a sage with elaborate analogies, theories, methods of instruction, and doctrines. Besides the Forms, which allegedly resided in a world of their own, Plato’s Socrates defended a theory of soul with Pythagorean roots. The soul was everlasting, without beginning or end; it underwent incarnations in the bodies of humans and other animals, progressing or retrogressing according to its behavior in mortality. Between incarnations it received rewards or punishments, and had an enhanced opportunity to behold the Forms in their pristine purity.
In his Republic and Phaedrus, Plato had provided a more complex model of the soul than the simple soul of the Phaedo: there were three parts of the soul, the intellect, the thymos or ego, and the appetites. On this basis, he could analyze moral failure not as ignorance of what is best, as it was for the historical Socrates, but as the abdication of authority of the highest part of soul, the intellect.
On the basis of his model of soul and his theory of values, Plato was able to develop a new theory of knowledge, which allowed for different levels of cognition. At the lowest level was an awareness of images and shadows; at a higher level, perception of physical objects; at a yet higher level was a grasp of mathematical structures; and at the highest level was an intuition of the Forms themselves. In this hierarchical picture, each level darkly mirrored the level above it. The most real realm was the highest, the world of Forms. Lower levels were pale imitations of the higher. Reality and knowledge proceeded from the top down to the mundane.
How exactly Plato interacted with other thinkers of his time is unclear. We get stories of contemporaries making fun of his Forms. But we don’t have any detailed accounts of interactions in his middle period. In his dialogues we find constructive accounts of Plato’s theories, but no strong evidence of debates with rival thinkers—not since his contentions with Polycrates and Isocrates. Surely, there were debates among intellectuals. But it appears that Plato, perhaps sheltered to some extent by the Academy with its lectures and discussions, was able to pursue his theories in relative peace. In the Phaedrus we have him kibbitzing in the realm of oratory, where he seems to be following a similar line to his thoughts in the Gorgias.
The era of good feelings, however, seems to collapse in the period after Plato’s second voyage. And a significant impulse for the collapse seems to come from inside the Academy itself.
At the age of seventeen, Aristotle son of Nicomachus, arrived from Stagira, a city in Chalcidice. The age of a young freshman, he is unlikely to have had much contact with philosophical thought before his arrival. His father had been a physician to the king of Macedonia, which gave him connection with important people in the north. His father had died as had his mother, leaving Aristotle an orphan in the charge of his uncle. Presumably the Academy, which increasingly was drawing the best minds of the Greek world as a kind of educational institution and think tank, beckoned.
Aristotle seems to have arrived in 367 while Plato was in Syracuse. He soon was making waves. Early on, he began to develop his own system of philosophy, one that conflicted with basic principles of Plato’s theory and, what was worse, seemed to be both more coherent and more powerful than the visionary, but sometimes rather vague, conceptions of his master. Where Plato presented bold ideas but waved his hand at the details, Aristotle sought for tight connections, preferably logical ones, between his theoretical conceptions. Where Plato offered astute analyses in passing, but then moved on and let them drop, Aristotle would latch on to such analyses, including some of Plato’s, and develop them into complex theories he exploited in many applications.
From the outset, the young Aristotle was both a brilliant protégé and nemesis to Plato, challenging his master’s most cherished assumptions and offering a contrasting theory that was at once more rigorous and more commonsensical than his mentor’s utopian wordview.
[1] Diogenes Laertius 5.1; 5.9.