Letters 11.3

I know that the blush, too, is a habit of this sort, spreading suddenly over the faces of the most dignified men. It is, indeed more prevalent in youth, because of the warmer blood and the sensitive countenance; nevertheless, both seasoned men and aged men are affected by it. Some are most dangerous when they redden, as if they were letting all their sense of shame escape.

Seneca, Letters to Lucilius 11.3, translated by Richard Mott Gummere