[p. 429] to reproduce this definition the poet Lucretius wrote: 1
Naught save a body can be touched or touch.The Greeks also define body in another way, as τὸ τριχῆ διάστατον, or “that which has three dimensions.” But the Stoics maintain 2 that voice is a body, and say that it is air which has been struck; Plato, however, thinks that voice is not corporeal: “for,” says he, 3 “not the air which is struck, but the stroke and the blow themselves are voice.” Democritus, and following him Epicurus, declare that voice consists of individual particles, and they call it, to use their own words, ῥεῦμα ἀτόμων, 4 or “a stream of atoms.” When I heard of these and other sophistries, the result of a self-satisfied cleverness combined with lack of employment, and saw in these subtleties no real advantage affecting the conduct of life, and no end to the inquiry, I agreed with Ennius' Neoptolemus, who rightly says: 5
Philosophizing there must be, but by the few;
Since for all men it's not to be desired.
XVI
[16arg] On the function of the eye and the process of vision.I HAVE observed that the philosophers have varying opinions about the method of seeing and the nature of vision. The Stoics say 6 that the causes of sight are the emission of rays from the eyes to those objects which can be seen, and the simultaneous
