Institutio Oratoria

The worst form of politeness, as it has come to be called, is that of mutual and indiscriminate applause, a practice which is unseemly, theatrical and unworthy of a decently disciplined school, in addition to being the worst foe to genuine study. For if every effusion is greeted with a storm of ready-made applause, care and industry come to be regarded as superfluous.

The audience no less than the speaker should therefore keep their eyes fixed on their teacher's face, since thus they will learn to distinguish between what is praiseworthy and what is not: for just as writing gives facility, so listening begets the critical faculty.