So do atheists oppose slavery? Do they believe in an objective human right to liberty? Well, there are no objective human rights of any kind on atheism. Human beings are just accidents in an accidental universe, and collections of atoms do not mysteriously accrue “rights”. There is no natural right to liberty on atheism. Now consider abortion, which is favored by most atheists. Like slavery, abortion declares an entire class of human beings as non-persons in order to justify preserving their own happiness and prosperity by means of violence. That’s exactly what slavery does, except abortion is worse than slavery, because you actually kill the person you are declaring as a non-person instead of just imprisoning them.