Seneca · On the healing power of the mind
Letters 78.19
You may tell me now of whatever you like—of colds, hard coughing-spells that bring up parts of our entrails, fever that parches our very vitals, thirst, limbs so twisted that the joints protrude in different directions; yet worse than these are the stake, the rack, the red-hot plates, the instrument that reopens wounds while the wounds themselves are still swollen and that drives their imprint still deeper. Nevertheless there have been men who have not uttered a moan amid these tortures. “More yet!” says the torturer; but the victim has not begged for release. “More yet!” he says again; but no answer has come. “More yet!” the victim has smiled, and heartily, too. Can you not bring yourself, after an example like this, to make a mock at pain?
Seneca, Letters to Lucilius 78.19, translated by Richard Mott Gummere