Friedrich Nietzsche, Beyond Good And Evil

Digressions, objections, delight in mockery, carefree mistrust are signs of health; everything unconditional belongs in pathology.

In individuals, insanity is rare; but in groups, parties, nations, and epochs it is the rule.

What a time experiences as evil, is usually an untimely echo of what was formerly experienced as good--the atavism of a more ancient ideal.