standard ; mi also does Posidonius in his treatise On the Standard. In their theory of dialectic most of them see tit to take as their starting-point the topic of voice. Now voice is a percussion of the air or the proper object of the sense of hearing, as Diogenes the Babylonian says in his handbook On Voice. While the voice or cry of an animal is just a percussion of air brought about by natural impulse, man's voice is articulate and, as Diogenes puts it, an utterance of reason, having the quality of coming to maturity at the age of fourteen. Furthermore, voice according to the Stoics is something corporeal : I may cite for this Archedemus in his treatise On Voice, Diogenes, Antipater and Chrysippus in the second book of his Physics. For whatever produces an effect is body ; and voice, as it proceeds from those who utter it to those who hear it, does produce an effect. Reduced to writing, what was voice becomes a verbal expression, as " day " ; so says Diogenes. A statement or proposition is speech that issues from the mind and signifies something, e.g. " It is day." Dialect (Slu.- Xcktos) means a variety of speech which is stamped on one part of the Greek world as distinct from another, or on the Greeks as distinct from other races ; or, again, it means a form peculiar to some particular region, that is to say, it has a certain linguistic quality ; e.g. in Attic the word for " sea " is not 6d\acr(To. but OdXarra, and in Ionic " day " is not -qfxepa but f)p£prj. Elements of language are the four-and-twenty letters. " Letter," however, has three meanings : (1) the particular sound or element of speech ; (2) its written symbol <>r character ; (3) its name, as