– Do you think, replied Epictetus, that, as in other things, so in speaking, there is an art by which he who understands it speaks skilfully, and he who doth not, unskilfully?
– I do think so.
– He, then, who by speaking both benefits himself and is able to benefit others, must speak skilfully; but he who rather hurts, and is hurt, must be unskilful in this art of speaking. For you may find some speakers hurt, and others benefited. And are all hearers benefited by what they hear? Or will you find some benefited, and some hurt?
– Then those who hear skilfully are benefited, and those who hear unskilfully, hurt.
– Is there an art of hearing, then, as well as of speaking?
– It seems so.
– If you please, consider it thus too. To whom do you think the practice of music belongs?
– To a musician.
– To whom the proper formation of a statue?
– To a statuary.
– And do not you imagine some art necessary to view a statue skilfully?
– I do.
(The Discourses of Epictetus, ch. xxiv, tr. Mrs. Elizabeth Carter)