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C.S. Lewis, Atheism, and the Genetic Fallacy

December 21, 2023


Sigmund Freud and Karl Marx adopted similar strategies to discredit belief in God. Freud held that belief in God arose from an unconscious childish wish for protection from a heavenly father figure: “At bottom God is nothing more than an exalted father.” Marx held that belief in God arose from economic alienation: “Religion is the opium of the people.” According to Freud and Marx, the belief in God arose from wish fulfillment or exploitation, and so, it might be concluded, God does not exist. 

Both of these critiques are logically fallacious. In his book Socratic Logic, Peter Kreeft points out that the genetic fallacy

consists in “refuting” an idea by showing some suspicious psychological origin of it. . . . No matter how egregious the psychological origins of a belief may be, the logic of the argument for it is independent of the psychology. If Einstein had been a vicious Nazi and had discovered the Theory of Relativity only in order to give Hitler the atom bomb to kill his enemies and conquer the world, that would not prove that E does not equal MC². 

In fact, important scientific discoveries have had unlikely origins. The inventor of the periodic table, Dmitri Mendeleev, discovered the relationship between chemical elements and atomic weight through a vivid dream. The chemist August Kekulé gained insight into the structure of atoms in benzene when he dreamed of a snake eating its own tail. The microbiologist Alexander Fleming discovered that penicillin destroys bacteria because he didn’t properly clean his lab. The genetic fallacy shows that genesis of an idea does not determine the truth of an idea. So, even if Freud and Marx were right about the psychological origins of belief in God, that would not show that God does not exist.

But were Freud and Marx right? Discovering the psychological origins of beliefs can be tricky. Did I come to believe house painting is a noble profession because of a traumatic experience in first grade while finger painting with Peter, an unrecognized fear of my father-in-law Miles, or a misplaced jealousy of my college roommate Chad? If I visit a psychologist for years, I may still never know for sure.  

The genetic fallacy is a fallacy whether used for or against atheism.

But, supposedly, in all times and in all cultures, everyone in the world who believes in God has exactly the same psychological motivation? Given the vast diversity of the human experience, this is hard to believe. Even psychologists are amateurs about those they have never personally evaluated. As Justice Scalia pointed out, “Interior decorating is a rock-hard science compared to psychology practiced by amateurs.” 

But suppose, for the sake of argument, that we could somehow know that everyone in the world, in every century and in every culture, who believes in God in fact does have exactly the same psychological motivation. This would still not show that God does not exist. After all, God could design us so that common psychological motivations lead human beings to believe that God exists. 

On the other hand, maybe distorted psychological motivations explain not believing in God. In his book Faith of the Fatherless: The Psychology of Atheism, NYU Professor Emeritus of Psychology Dr. Paul Vitz offers biographical surveys of the lives of famous atheists, including Marx, Freud, Sartre, Nietzsche, Hitchens, Dawkins, and Dennett. Vitz discovered a common pattern. All of these famous atheists had dead, absent, or abusive fathers. Vitz writes, “Therefore, in the Freudian framework, atheism is an illusion caused by the oedipal desire to kill the father (God) and replace him with oneself.” 

But even if it were true that all atheists share the same experience of defective fathers (all of them?), that would provide no evidence that God does exist. Vitz’s psychological genealogy of atheism as arising from defective father syndrome may be true, but it does not prove that atheism is false. The genetic fallacy is a fallacy whether used for or against atheism.

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In his essay “Bulverism,” the ex-atheist C.S. Lewis points out still further problems with trying to discredit beliefs by pointing to their (alleged) psychological genesis: “The first is, are all thoughts thus tainted at the source, or only some? The second is, does the taint invalidate the tainted thought—in the sense of making it untrue—or not? If they say that all thoughts are thus tainted, then, of course, we must remind them that Freudianism and Marxism are as much systems of thought as Christian theology or philosophical idealism. The Freudian and Marxian are in the same boat with all the rest of us, and cannot criticize us from outside. They have sawn off the branch they were sitting on.” If all thoughts are mere rationalizations of erotic desires, then so is the thought that “all thoughts are mere rationalizations of erotic desires.” If all claims are unjustified epiphenomena generated by an economic superstructure, then also unjustified is the claim that “all claims are unjustified epiphenomenal rationalizations generated by an economic superstructure.” Such thoughts and claims are self-defeating.

Lewis continues, “If, on the other hand, they say that the taint need not invalidate their thinking, then neither need it invalidate ours. In which case they have saved their own branch, but also saved ours along with it.” If Freud can make statements that are true, despite the irrational workings of his subconscious, then so can the critic of Freud. If Marx can have thoughts that correspond to reality, despite economic circumstances, then so can the critic of Marx. But, in this case, in vain do we try to discredit an idea on the basis of its alleged origin as a rationalization of erotic or economic interests.

Finally, the genetic fallacy leads to lazy thinking. Rather than actually engaging with what a person says, assessing the reasons for or against the belief in question, the lazy thinker can dismiss any belief by discrediting its messenger. As Thomas Sowell pointed out, “It is amazing how many people think that they can answer an argument by attributing bad motives to those who disagree with them. Using this kind of reasoning, you can believe or not believe anything about anything, without having to bother to deal with facts or logic.” A mind is a terrible thing to waste on logical fallacies.