One Good: The Mathematics of Ethics

Probably during the years at the Academy, Aristotle wrote a work known as Περὶ τἀγαθοῦ, on the good, exposing Plato’s teachings on the principles. Various sources confirm that Plato gave public lectures on the theme of the good, most notably Aristoxenus of Tarentum, who would in turn become Aristotle’s student. In his treatise on harmony, Aristoxenus recalls that, while many would gather to listen to Plato, they would leave dismayed since, instead of hearing about the good in the quotidian sense of the term, they would be subjected to speeches on mathematics and geometry, culminating with the statement of the identity of the good and the one. The testimony is worth quoting, despite the ritual reservations surrounding Aristoxenus’ reports, especially those about Plato