It is, however, said that Plato once disclosed this knowledge to the public in his lecture "On the Good" (), in which the Good () is identified with the One (the Unity, ), the fundamental ontological principle. The content of this lecture has been transmitted by several witnesses. Aristoxenus describes the event in the following words: "Each came expecting to learn something about the things that are generally considered good for men, such as wealth, good health, physical strength, and altogether a kind of wonderful happiness. But when the mathematical demonstrations came, including numbers, geometrical figures and astronomy, and finally the statement Good is One seemed to them, I imagine, utterly unexpected and strange; hence some belittled the matter, while others rejected it." Simplicius quotes Alexander of Aphrodisias, who states that "according to Plato, the first principles of everything, including the Forms themselves are One and Indefinite Duality (), which he called Large and Small ()", and Simplicius reports as well that "one might also learn this from Speusippus and Xenocrates and the others who were present at Plato's lecture on the Good".