The universe is a nasty, heartless place where most things wouldn’t mind killing you if you let them. No one is compelled to be nice; you or anyone could go on a murder spree, and all that is stopping you is your self-interest (it is very destructive to your personal bliss to knock down your social support system) and the self-interest of others, who would try to stop you. There is nothing ‘out there’ that imposes morality on you, other than local, temporary conditions, a lot of social enculturation, and probably a bit of genetic hardwiring that you’ve inherited from ancestors who lived under similar conditions. — PZ Myers (quoted in, Blogs About Nothing)