" We can believe in hierarchy. We can believe the universe was made just for us. Hierarchy and a major sense of entitlement are not insurmountable problems. The problem occurs when we treat those whom we believe lie beneath us as slaves. Religion once sustained human slavery. It was wrong then. When it blindly sanctions the slavery of every nonhuman animal, it is wrong now. "

― Cass R. Sunstein , Animal Rights: Current Debates and New Directions