When one contemplates the streak of insanity running through human history, it appears highly probable that homo sapiens is a biological freak, the result of some remarkable mistake in the evolutionary process. The ancient doctrine of original sin, variants of which occur independently in the mythologies of diverse cultures, could be a reflection of man's awareness of his own inadequacy, of the intuitive hunch that somewhere along the line of his ascent something has gone wrong.
Arthur Koestler, The Ghost in the Machine
human-evolution, insanity