There is no mask that temptation cannot wear, and the idea that Satan is purely a logician is an illusion held by not a few naive people. Many a shifty old man sees him as an opponent in an academic argument, but if he does the observer is still at the stage of games and trifles. Sometimes, though not often, the black desire to harm wins out over quicker and less bitter delights. When that happens, evil shows itself for what it truly is, not a way of life, but an attack on life itself.

The Impostor, translated by J. C. Whitehouse. Lincoln NE: University of Nebraska Press, 1999, pp.74–75 - L'imposture (The Impostor), 1927