Aristotle

384–322 BCE. Twenty years a student in Plato's Academy, then Alexander's tutor, then founder of the Lyceum — and the tradition's first systematic critic of his own teacher.

About 31 treatises survive out of roughly 200, in the form of lecture notes. The organization is his own: theoretical sciences (metaphysics, physics, natural philosophy), practical (ethics, politics), productive (rhetoric, poetics), with logic standing outside as the Organon, the instrument the others use.

The load-bearing doctrines, per sep-aristotle:

• Syllogistic — the first formalized system of logic and valid inference, arranged so that every deduction reduces to a form you can see is valid.
• Four causes — material, formal, efficient, final. An explanation is complete when it says what a thing is made of, what structure it has, what brought it about, and what it is for.
• Hylomorphism — ordinary objects are composites of matter and form; potentiality and actuality describe the passage between them.
• Eudaimonia — the practical sciences ask what a life going well consists in.

The break with Plato

He rejects univocity: the assumption that "good" or "being" names one essence everywhere it appears. In its place, core-dependent homonymy — a term can have several senses that still hang together, because each depends on one primary sense. That is a different diagnosis of the forms than "they do not exist"; it says the demand for a single essence behind a single word was the error.

Why this matters to the corpus's own arguments

• The final cause is the piece Descartes and the mechanists throw out, and discarding it is most of what "modern" means in western-philosophy. Spinoza goes furthest — nature acts for no end at all.
• Ethics as the study of a well-lived life, rather than of obligations, is the frame stoicism inherits and the one this spoke's third through-line follows.
• Core-dependent homonymy is a working answer in epistemology and semantics still, which is why the entry is not merely historical.

The other doctrine of the mean

[[doctrine-of-the-mean|Zhongyong]] arrived in the corpus on 2026-08-28 carrying the same English phrase, and Wikipedia disambiguates the two texts against each other at the top of its article. The overlap is real — virtue as the avoidance of excess and deficiency — and the divergence is where the comparison earns anything. Aristotle's mean is relative to the agent, sits between two named vices, and is found by practical wisdom in the case at hand, with no cosmology under it. The Confucian mean is centrality held constant, grounded in Heaven, and ends in a sincerity that "assists the transforming and nourishing powers of Heaven and Earth."

sep-aristotle is not the source of that contrast — this spoke's own note is, and the Neo-Confucian corner has been caught by the same trap once already, over li against Western universals (neo-confucianism). Aristotle's Nicomachean Ethics is unpaged here; when it arrives, the mean is the first thing to read against the Chinese text rather than alongside it.

Provenance: sep-aristotle (T1). Primary texts unread here.