Conscience, custom — the first makes cowards,
Makes saints of us sometimes, makes human beings.
The other makes Patriots, Papists, Protestants,
Makes Babbitts, Sadists, Swedes or Slovaks,
Makes killers of Kulaks, chlorinators of Jews,
Makes all who mangle, for lofty motives,
Quivering flesh, without qualm or question
To mar their certainty of Supreme Service.

— Aldous Huxley, Ape and Essence