Christian apologist Eric Hernandez claims that atheism—the view that there is no God or supernatural creative force—is self-defeating. He claims that if human cognitive faculties are the product of an unguided evolutionary process, then that would undercut the rationality of all of our beliefs (including belief in unguided evolution, and atheism).

In other words, if atheism is true then we cannot rationally believe in atheism. Eric calls this argument the Evolutionary Argument Against Naturalism.[1]

But why think that all of our beliefs would be undercut if our brains were the product of an unguided evolutionary process? Well, Eric claims:

If atheism is true, then the only explanation to our existence is naturalistic evolution—an unguided process via natural selection. And natural selection selects for things that help an organism survive, so its aim is survival value. Now if that’s the case, assuming that our beliefs cause our actions, then beliefs will be selected that are aimed at survival and not truth; that is to say, if atheism is true your beliefs don’t have to be true, they just have to help you survive. And if that’s the case, you have a defeater for any belief that your brain produces.[2] (Emphasis mine.)

In short, Eric is attempting to drive a wedge between adaptive behaviors that lead to reproductive fitness on the one hand, and brains that produce beliefs that are “aimed at truth” on the other; he’s proposing that naturalistic evolution would favor behaviors that aided in survival, yet would be blind to the truth-value of an organism’s beliefs. If this were true, then our cognitive faculties would not have evolved to accurately comprehend the environment around us. Instead, our species would have been selected only on the basis of who could best fight or run from predators, find enough food, and reproduce the most—regardless of what they actually believed.

You may be wondering: How could our early ancestors have been able to successfully identify predators, fight or run, find food, and reproduce, if they didn’t have the ability to accurately understand the environment? Eric contrasts two examples:

Suppose there is a car coming towards me, and I believe that if the car hits me I’m going to die, and the best way to survive is to jump out of the way. Assuming that my beliefs directly cause my actions, then my belief that moving out of the way would help me survive ensured my survival.

Now, let’s take the same scenario with a different set of beliefs. If a car was coming my way and I believed that I was Superman, and that a car hitting me would not kill me, however I also believe I need to conceal my identity and the best way to do that is to jump out of the way to appear human, then I had a different set of beliefs which were false, but they still caused behaviors that helped me survive. [So] if naturalism is true, and your beliefs are aimed at survival and not truth, then your beliefs don’t have to be true in order for you to survive.[3] (Emphasis mine.)

The first thing to notice is that his second example still contains true beliefs. While the person does falsely think that he’s Superman and getting hit by a car won’t kill him, these are merely “extras” built on top of other true beliefs; namely, there is a car and it is coming my way.

It seems this person’s true beliefs would still be favored by natural selection—at least more than the poor fellow who failed to identify the car and the fact that it was speeding toward him. (That person would probably die a lot sooner!) So evolution allowing “extra” delusional beliefs on top of a foundation of more basic true beliefs does not justify Eric’s claim that natural selection would be totally blind to true beliefs, or that, “If atheism is true, knowledge can’t exist.”[4] To the contrary, Eric’s example is a clear case of justified true beliefs at least partially helping a person survive!

Why Eric is Kinda Right

Human beings are not as innately “rational” as we often make ourselves out to be, and natural selection can favor certain types of false beliefs.[5] On the whole, human beings are more like Eric’s deluded Superman than some kind of Creature of Reason. As Michael Shermer writes, “The study of cognitive biases has revealed that humans are anything but the Enlightened ideal of rational calculators carefully weighing the evidence for and against beliefs.”[6] We’re actually pretty bad in a lot of ways. Think of all the wacky beliefs that persist around the world–from various religions, to superstitions, to conspiracy theories. Or consider the range of cognitive biases that are hard-wired in us. This does not suggest, however, that we don’t know anything; only that we need to be skeptical about what we believe and what we claim is true.

In fact, this kind of skepticism is why science has been so successful. We’ve been able to avoid the most common pitfalls in thinking by developing methods that do not depend on our “stock” cognitive hardware. Science forces us to challenge our assumptions, measure everything multiple times in multiple ways, get input from other people, put our ideas out in public for criticism, and repeat experiments over and over.[7] The procedures of double-blind experiments, statistical analysis, and peer review are not inborn methods of human reasoning, but are the products of thousands of years of intellectual and cultural progression that we must learn. Without these methods we’d still be simple fisherman and herders.

Consider a common fallacy of human thought: post hoc reasoning. This occurs when we falsely infer that because two events were closely related in time, that one event caused the other. For example, some baseball players think that wearing the same pair of underwear during the World Series will help them win; or some drivers associate a full moon with a higher rate of car accidents; or some Native tribes think that performing a rain dance will cause it to rain–when in fact there is zero causal connections between any of these events.

This oddity in our reasoning is best explained through evolution. Associative learning–connecting event A to event B–is a heuristic that developed in our ancestors which helped them more successfully navigate the environment. Post hoc reasoning is an instance of overinterpreting this heuristic. Because our ancestors were often faced with split-second decisions, they adopted a quick-and-dirty rule of thumb: “If B followed A, then A caused B.” And most of the time this works. But sometimes it leads people astray; this is where belief in magic underwear, rain dances, and the dangers of a full moon come from.

So Eric is absolutely right that natural selection can favor false beliefs and even design cognitive faculties that are unreliable in certain ways–this actually best explains why we have them! But this could only be plausible on a background of more basic true beliefs. In other words, evolution wouldn’t have made it as far as mammals and hominids if they weren’t able to “identify the speeding car” coming in their direction, to use Eric’s example.

The Possibility of Being Wrong

Recall Eric’s claim, “If naturalism is true…then your beliefs don’t have to be true in order for you to survive.” Here he seems to be suggesting that because it is possible (read, logically possible) for an organism to survive with a head full of delusional beliefs, that this somehow undermines all knowledge (or becomes a “defeater”). But of course this doesn’t follow. Logical possibilities do not determine what is probably true, and knowledge is not confined to logical certainty without the possibility of error.

If this were true then Eric would be faced with the same overwhelming skepticism as everybody else. To show why, we can simply reverse the argument on Eric: it is logically possible that Eric is a brain in a vat and is being deceived into believing that he has arms and legs, has a wife and kids, and that Jesus died for his sins, when none of that is really true. This mere possibility, however, does nothing to suggest that Eric actually is a brain in a vat and without a physical body. Such a possibility would not “defeat” all of Eric’s knowledge or go to show that he lacks all justification for believing what he does.

In a similar way, the logical possibility of evolution favoring organisms with all false beliefs does nothing to show that such a scenario is probable. To the contrary, I would argue it is more probable that certain beliefs lead to certain behaviors, and that because natural selection either rewards or punishes adaptive and maladaptive behavior, over time the mechanisms that produce belief would do so more often in the direction of more accurate ones. In other words, over time there would be selection pressure for true beliefs and for more reliable belief-producing mechanisms.[8]

So Eric is simply wrong when he says, “Beliefs will be selected that are aimed at survival and not truth.”

Using Your Brain to Trust Your Brain

A final misstep in Eric’s argument is when he criticizes atheists for using “circular reasoning” when defending the reliability of their cognitive faculties. He claims that the atheist’s argument reduces to them saying, “I can trust my brain because my brain tells me that I can trust it.”[9] While it is true atheists face this kind of epistemic circularity, it’s true for everybody, including Eric. This isn’t a criticism that should be taken seriously. Again, we can flip the argument around: how is Eric able to trust that his brain can recognize truth without relying on information received through his brain? Any answer that he gives will be things that he believes, using his brain!

Yet I doubt Eric will think his entire worldview is “self-defeating” because of it.

What this means is that Eric’s argument is based on a double standard. Philosophers have known for quite some time that many of our basic beliefs and belief-forming practices are plagued with epistemic circularity.[10] This is unavoidable, but it is not a reason to give up all knowledge.

Watch Eric use his double standard against Matt Dillahunty:


Eric Hernandez’ argument that “atheism is self-defeating” doesn’t hold water. Eric’s example of false beliefs that lead to adaptive behavior still preserve more than one true belief. However, we can (and should) grant Eric’s general claim that unguided evolution would not produce perfectly reliable cognitive faculties. But, to the benefit of the atheist, the facts of our widespread psychological biases and errors end up supporting that view. This also goes to show why the methods of science are so successful, and how important it is that we subject all of our beliefs to testing and skepticism.

We also saw that the mere possibility of being wrong, or having all false beliefs, doesn’t entail that we know nothing. I argued that the same is true for Eric: because he is a fallible creature that perceives the world from a subjective point of view, he can never close the door on the possibility of global deception, but that shouldn’t stop him from being confident in the genuine knowledge that he has.

And last of all, epistemic circularity isn’t a bad thing, and it doesn’t undercut all of our knowledge. Or if it does, Eric faces the same dilemma.

End Notes

  1. Eric’s argument is an oversimplified and quite different version than the more sophisticated one developed by Alvin Plantinga. See his book Warrant and Proper Function.
  2. Eric Hernandez in interview on the Sin Boldly Podcast, “Why I’m Not An Atheist. With Eric Hernandez and Spencer Hawkins.” 71
  3. Ibid. Sin Boldly Podcast.
  4. Ibid. Sin Boldly Podcast.
  5. Michael Shermer, The Believing Brain, 2011.
  6. Ibid. Shermer, p. 278.
  7. PZ Myers, “Alvin Plantinga gives philosophy a bad name,” Pharyngula, May 29, 2009.
  8. Alvin Plantinga, “Reply to Beilby’s Cohorts,” Naturalism Defeated? Edited by James Beilby, p. 257.
  9. Eric Hernandez Ministries, “You Won’t Believe What this Atheist Admits…” YouTube,
  10. Christian philosopher William Alston writes, “…none of our most basic “doxastic” (belief-forming) practices, including introspection, memory, and reasoning of various sorts, can be noncircularly shown to be reliable.” Perceiving God: The Epistemology of Religious Experience, (p. 103).

Image: screenshot, Eric Hernandez Ministries, YouTube.