De Oratore

Everything rests with the face, and the face in turn is under the power of the eyes;⁠a and therefore the oldest of our countrymen showed more judgment in not applauding even Roscius himself to any great degree when he performed in a mask; for all the powers of action proceed from the mind, and the countenance is the image of the mind, and the eyes are its interpreters. This, indeed, is the only part of the body that can effectually display as infinite a number of expressions and changes, as there is of emotions in the soul; nor can any speaker produce the same effect with his eyes shut, as with them open. Theophrastus indeed has told us, that a certain Tauriscus used to say, that a player who pronounced his part gazing on any particular object was like one who turned his back on the audience. Great care in managing the eyes is therefore necessary; for the appearance of the features is not to be too much varied, lest we fall into some absurdity or distortion. It is the eyes, by whose intense or languid gaze, as well as by their quick glances and gaiety, we indicate the workings of our mind with a particular aptitude to the tenor of our discourse; for action is, as it were, the speech of the body, and ought therefore the more to accord with that of the soul. And Nature has given eyes to us, to declare our internal emotions, as she has bestowed a mane, tail, and ears on the horse and the lion.