" The existence of all these copies of ourselves would then seem to me to present a moral and ethical quandary. If no matter what choices I make in life, there will be a version of me that will take the opposite choice, then why does it matter what I choose? There will be a branch in the multiverse for every option I might have chosen. There are branches in which I become as evil as Stalin and Hitler and there are branches where I am loved as a successor to Gandhi. I might as well be selfish and make the choices that benefit me. Irrespective of what I choose, the kind and generous choice will be made by an infinite number of copies living in an infinite number of other branches. This seems to me to be an ethical problem because simply believing in the existence of all these copies lessens my own sense of moral responsibility. "

― Lee Smolin , Einstein's Unfinished Revolution: The Search for What Lies Beyond the Quantum