book, atheistScientists and atheists do something that many believers find repellent: we shatter their perception of their relationship to the universe. And understandably, they don’t like that.

Most religious people in the West have a specific model of how the world works that is based on our cultural history as the progeny of nomadic herders and that still resonates strongly with all of us—the father-child relationship, the patriarchy. We have a wise leader who guides us all, punishes us when we stray, offers largesse to those in his favor, and unites the whole tribe in common cause. Those Bronze Age sheepherders lived this way, and for them patriarchy made sense. It was a strategy for survival that worked well. But it shapes the way we see the world even now. Ask any Christian on any Sunday morning about flocks and sheep and shepherds, and he or she will understand the metaphor, despite never having been in contact with animals other than a household pet.

Patriarchy is also a powerful idea because it posits a set of very personal relationships. The father is remote because of his great responsibilities, but at the same time, we all want that pat on the shoulder, the encouraging word, the opportunity to serve and win distinction in Father’s eyes by virtue of our dutifulness. It’s a familial relationship, tightly knit and long-established, wherein we are respectful dependents and the leader of the tribe relies on our service.

Beyond the family and tribe, though, this vision has been extended to the entire universe. A great Patriarch in the Sky is our leader and guide, responsible for making the grand strategic decisions about where our tribe will go, and watchfully making sure that the tribe’s unity is not disrupted by wayward ideas from nonconformists. His central concern, which we all share, is that our people should thrive, and even if he is stern at times, it is because he cares so much that we succeed. And he knows each one of us personally, just as the leader of tribe or clan in pastoral days would have, and he can give us an approving stroke or a damning, angry smiting, depending on whether we help or hinder the work of getting the flocks to the summer pasturage.

Read your Bible. It’s saturated with this primitive herdsman mentality: God the father, the sheep and goats, the lost lambs and the Lamb of God, flocks and herds. It’s anthropologically fascinating and not necessarily an evil metaphor (unless you’re a woman—the patriarchy is deeply misogynistic). One of its most appealing aspects is that it makes one’s relationship with the universe close and personal, in a very simple kind of relatedness, that of father and child. It reduces all the complexity of deep time to the metaphor of a single generation, direct and immediate, and it colors everything about how we view our place in the world: domination and submission, leader and follower, wisdom and naïveté, master and servant, command and obedience. Biblical morality also tangles up our material relationship with the world in those paternal virtues of love and concern and discipline. Its patriarchal emphasis muddles ethical concerns, which fits with the portrait of the omnipotent God painted by the Bible.

I can sympathize. I loved and respected my father, and any attempt by an outsider to defame or complicate or diminish him would trigger a resentful response from me. Christians and Muslims and Jews have been told from their earliest years that God is their father, with all the attendant associations of that argument, and what are we atheists doing? Telling them that, no, he is not, and not only that, you don’t have a heavenly father at all—the imaginary guy you are worshipping is actually a hateful monster and an example of a bad and tyrannical father. And you aren’t even a very special child—you’re a mediocre product of a wasteful and entirely impersonal process.

By comparison, that whole business of breaking the news about Santa Claus is small potatoes. Reality is harsh, man.

But it is reality. We’ve done the paternity tests, we’ve traced back the genealogy, and we’re doing all kinds of in-depth testing of the human species. People are apes and the descendants of apes, who were the descendants of rat-like primates, who were the children of reptiles, who were the spawn of amphibians, who were the terrestrial progeny of fish, who came from worms, who were assembled from single-celled microorganisms, who were the products of chemistry. Your daddy was a film of chemical slime on a Hadean rock, and he didn’t care about you—he was only obeying the laws of thermodynamics.

You are you not because of some grand design but because of chance, contingency, and selection.

Your genome is a mess of detritus with a tiny fraction of well-honed functionality, and your body is cobbled together from the framework of a tetrapod. You bear the scars of chance throughout, and you are mostly unaware of them because selection—that is, the death of millions—has patched them over. But they’re present to the eye that will look for them. You aren’t the best at much of anything: you’re weaker, slower, more fragile, and clumsier than the other species we compete with, and although you’ve got a bigger brain, the majority of Americans, at least, consider it a virtue to keep it ignorant and unused. Universally, we have difficulty thinking in the long term, while we are very good at exploiting our environment in the short term, which is leading to some interesting and possibly fatal consequences.