Institutio Oratoria

For we can indicate our will not merely by a gesture of the hands, but also with a nod from the head: signs take the place of language in the dumb, and the movements of the dance are frequently full of meaning, and appeal to the emotions without any aid from words. The temper of the mind can be inferred from the glance and gait,

Nor is it wonderful that gesture which depends on various forms of movement should have such power, when pictures, which are silent and motionless, penetrate into our innermost feelings with such power that at times they seem more eloquent than language itself. On the other hand, if gesture and the expression of the face are out of harmony with the speech, if we look cheerful when our words are sad. or slake our heads when making a positive assertion, our words will not only lack weight, but will fail to carry conviction.