A raving demagogue counseling hatred

So next time you hear a raving demagogue counseling hatred for other, slightly different groups of humans, for a moment at least see if you can understand his problem: He is heeding an ancient call that – however dangerous, obsolete, and maladaptive it may be today – once benefitted our species.

— Carl Sagan and Ann Druyan, 1993

From the book Shadows of Forgotten Ancestors: A Search for Who We Are