Letters 59.8

This, he declares, is still more necessary for men like ourselves; for soldiers have often feared an enemy without reason, and the march which they thought most dangerous has in fact been most secure; but folly brings no repose, fear haunts it both in the van and in the rear of the column, and both flanks are in a panic. Folly is pursued, and confronted, by peril. It blenches at everything; it is unprepared; it is frightened even by auxiliary troops. But the wise man is fortified against all inroads; he is alert; he will not retreat before the attack of poverty, or of sorrow, or of disgrace, or of pain. He will walk undaunted both against them and among them.

Seneca, Letters to Lucilius 59.8, translated by Richard Mott Gummere