Book 3
7.10
Further, one ought not to make use of all kinds of correspondenceAdaptation of voice, features, etc., to the subject. together; for in this manner the hearer is deceived. I mean, for instance, if the language is harsh, the voice, features, and all things connected should not be equally harsh; otherwise what each really is becomes evident. But if you do this in one instance and not in another, the art escapes notice, although the result is the same. If mild sentiments are harshly expressed or harsh sentiments mildly, the speech lacks persuasiveness.
