A naturalistic universe is one that consists of energy and matter and other natural entities, such as vacuums, operating in a closed system in time and space, in which no transcendent, supernatural, divine being or superhuman power exists as creator, sustainer, guide or judge. Such a universe has come to exist by chance - not by design or providence but by purposeless natural forces and processes. There is no inherent, ultimate meaning or purpose. Any meaning or purpose that exists for humans in a naturalistic universe is constructed by and for humans themselves. When the natural forces of entropy eventually extinguish the human race - if some natural or humanmade disaster does not do so sooner - there will be no memory or meaning, just as none existed before human consciousness evolved.

If that is the nature of reality, then what grounds are there for believing in universal benevolence and human rights? There do not seem to be any:

To begin with, let us first observe that a naturalistic universe does not seem to offer any moral guidance at all ... Organisms do tend to “want” to survive. But on evolutionary grounds per se we cannot say that it was morally good or bad that the dinosaurs lived or died, for instance. It just happened.

This has not stopped people trying to provide some, of course. Some seek to secure human rights in the evolutionary pursuit of survival (which at most would ground our commitment to the survival of our offspring or tribe, and certainly not our entire species). Some insist that humans are fundamentally benevolent towards other human beings on the grounds of our humanity alone (which comes unstuck very quickly when we consider human history, but even if it were true, naturalistically speaking we cannot derive an “ought” from an “is”). Some look for a social contract description, in which we agree to affirm and defend human rights simply as a collective decision (which again, even if it were true, “does not and cannot compel people to believe in benevolence and rights as moral truths upon which they are obliged to act even if to their own detriment.”) And so forth.

Ultimately, Smith argues, they all fail on a logical level. We believe in human rights on the basis of convictions about humanity that grew in Christian soil, and cannot be grounded in a materialist account of reality. It is as if we are trying to remove the foundations from under a house, but hoping the house stays standing and nobody notices. Well: people have noticed. As to whether the house stays standing in a post-Christian context—and this was Nietzche’s objection too, from a completely different perspective—we shall see.