"For evil to take place, the acts of a few people are not sufficient; the great majority also has to remain indifferent. That is something of which we are all quite capable."

Next Quote

. . . as to moral feeling, this supposed special sense, the appeal to it is indeed superficial when those who cannot think believe that feeling will help them out, even in what concerns general laws: and besides, feelings which naturally differ infinitely in degree cannot furnish a uniform standard of good and evil, nor has any one a right to form judgments for others by his own feelings. . . .

— Immanuel Kant