Plutarch, On the Education of Children 9

from http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Plutarch/Moralia/De_liberis_educandis*.html

(Obviously some speakers are 'too theatrical' and Plutarch doesn't want children to be trained that way.)

I advise then (for I return now to my original theme) that, as one should always be careful to avoid the theatrical and melodramatic style, so, on the other hand, one should exercise the same caution to avoid triviality and vulgarity in style; for a turgid diction is unfitted for a man in public life, and a barren style is too unimpressive; but as the body ought to be not merely healthy but also sturdy, so also speech should be not merely free from fault but vigorous too. For the cautious is merely commended, but the audacious is admired as well. It so happens that I entertain the same opinion also in regard to mental disposition. For a man should not be bold, on the one hand, or, on the other, pusillanimous and cowering, since the one resolves itself into impudence, and the other into servility. Always to pursue the middle course in everything is artistic and in good taste.