" Survival machines could evolve to be completely selfish and self-centered, but there is something that keeps their pure selfishness in check, and that is the fact that other survival machines are inclined “to hit back” if attacked, to retaliate if exploited, or to attempt to use or abuse other survival machines first. "

― Michael Shermer , The Moral Arc: How Science and Reason Lead Humanity toward Truth, Justice, and Freedom