Editor’s note: ENV is pleased to share the following excerpt from Nancy Pearcey’s new book, Finding Truth: Five Principles for Unmasking Atheism, Secularism, and Other God Substitutes. A Fellow of Discovery Institute’s Center for Science & Culture, Pearcey is a professor and scholar-in-residence at Houston Baptist University and editor-at-large of The Pearcey Report. She is author of the 2005 ECPA Gold Medallion Award winner Total Truth: Liberating Christianity from Its Cultural Captivity and other books. An ID the Future podcast with Nancy Pearcey about this excerpt from her book can be found at Is Human Reason Reliable? Interview with Nancy Pearcey.

A major way to test a philosophy or worldview is to ask: Is it logically consistent? Internal contradictions are fatal to any worldview because contradictory statements are necessarily false. "This circle is square" is contradictory, so it has to be false. An especially damaging form of contradiction is self-referential absurdity — which means a theory sets up a definition of truth that it itself fails to meet. Therefore it refutes itself….

An example of self-referential absurdity is a theory called evolutionary epistemology, a naturalistic approach that applies evolution to the process of knowing. The theory proposes that the human mind is a product of natural selection. The implication is that the ideas in our minds were selected for their survival value, not for their truth-value.

But what if we apply that theory to itself? Then it, too, was selected for survival, not truth — which discredits its own claim to truth. Evolutionary epistemology commits suicide.

Astonishingly, many prominent thinkers have embraced the theory without detecting the logical contradiction. Philosopher John Gray writes, "If Darwin’s theory of natural selection is true,… the human mind serves evolutionary success, not truth." What is the contradiction in that statement?

Gray has essentially said, if Darwin’s theory is true, then it "serves evolutionary success, not truth." In other words, if Darwin’s theory is true, then it is not true.

Self-referential absurdity is akin to the well-known liar’s paradox: "This statement is a lie." If the statement is true, then (as it says) it is not true, but a lie.

Another example comes from Francis Crick. In The Astonishing Hypothesis, he writes, "Our highly developed brains, after all, were not evolved under the pressure of discovering scientific truths but only to enable us to be clever enough to survive." But that means Crick’s own theory is not a "scientific truth." Applied to itself, the theory commits suicide.

Of course, the sheer pressure to survive is likely to produce some correct ideas. A zebra that thinks lions are friendly will not live long. But false ideas may be useful for survival. Evolutionists admit as much: Eric Baum says, "Sometimes you are more likely to survive and propagate if you believe a falsehood than if you believe the truth." Steven Pinker writes, "Our brains were shaped for fitness, not for truth. Sometimes the truth is adaptive, but sometimes it is not." The upshot is that survival is no guarantee of truth. If survival is the only standard, we can never know which ideas are true and which are adaptive but false.

To make the dilemma even more puzzling, evolutionists tell us that natural selection has produced all sorts of false concepts in the human mind. Many evolutionary materialists maintain that free will is an illusion, consciousness is an illusion, even our sense of self is an illusion — and that all these false ideas were selected for their survival value.

So how can we know whether the theory of evolution itself is one of those false ideas? The theory undercuts itself.

A few thinkers, to their credit, recognize the problem. Literary critic Leon Wieseltier writes, "If reason is a product of natural selection, then how much confidence can we have in a rational argument for natural selection? … Evolutionary biology cannot invoke the power of reason even as it destroys it."

On a similar note, philosopher Thomas Nagel asks, "Is the [evolutionary] hypothesis really compatible with the continued confidence in reason as a source of knowledge?" His answer is no: "I have to be able to believe … that I follow the rules of logic because they are correct — not merely because I am biologically programmed to do so." Hence, "insofar as the evolutionary hypothesis itself depends on reason, it would be self-undermining."

Darwin’s Selective Skepticism

People are sometimes under the impression that Darwin himself recognized the problem. They typically cite Darwin’s famous "horrid doubt" passage where he questions whether the human mind can be trustworthy if it is a product of evolution: "With me, the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy."

But, of course, Darwin’s theory itself was a "conviction of man’s mind." So why should it be "at all trustworthy"?

Surprisingly, however, Darwin never confronted this internal contradiction in this theory. Why not? Because he expressed his "horrid doubt" selectively — only when considering the case for a Creator.

From time to time, Darwin admitted that he still found the idea of God persuasive. He once confessed his "inward conviction … that the Universe is not the result of chance." It was in the next sentence that he expressed his "horrid doubt." So the "conviction" he mistrusted was his lingering conviction that the universe is not the result of chance.

In another passage Darwin admitted, "I feel compelled to look to a First Cause having an intelligent mind in some degree analogous to that of man." Again, however, he immediately veered off into skepticism: "But then arises the doubt — can the mind of man, which has, as I fully believe, been developed from a mind as low as that possessed by the lowest animal, be trusted when it draws such grand conclusions?"

That is, can it be trusted when it draws "grand conclusions" about a First Cause? Perhaps the concept of God is merely an instinct programmed into us by natural selection, Darwin added, like a monkey’s "instinctive fear and hatred of a snake."

In short, it was on occasions when Darwin’s mind led him to a theistic conclusion that he dismissed the mind as untrustworthy. He failed to recognize that, to be logically consistent, he needed to apply the same skepticism to his own theory.

Modern followers of Darwin still apply the theory selectively. Harvard paleontologist Stephen Jay Gould wrote, "Darwin applied a consistent philosophy of materialism to his interpretation of nature," in which "mind, spirit, and God as well, are just words that express the wondrous results of neuronal complexity." In other words, God is an idea that appears in the human mind when the electrical circuitry of the brain has evolved to a certain level of complexity.

To be logically consistent, however, Gould should turn the same skepticism back onto Darwin’s ideas, which he never did. Gould applied his evolutionary skepticism selectively — to discredit the idea of God.

Applied consistently, Darwinism undercuts not only itself but also the entire scientific enterprise. Kenan Malik, a writer trained in neurobiology, writes, "If our cognitive capacities were simply evolved dispositions, there would be no way of knowing which of these capacities lead to true beliefs and which to false ones." Thus "to view humans as little more than sophisticated animals …undermines confidence in the scientific method."

Just so. Science itself is at stake. John Lennox, professor of mathematics at the University of Oxford, writes that according to atheism, "the mind that does science … is the end product of a mindless unguided process. Now, if you knew your computer was the product of a mindless unguided process, you wouldn’t trust it. So, to me atheism undermines the rationality I need to do science."

Of course, the atheist pursuing his research has no choice but to rely on rationality, just as everyone else does. The point is that he has no philosophical basis for doing so. Only those who affirm a rational Creator have a basis for trusting human rationality.

The reason so few atheists and materialists seem to recognize the problem is that, like Darwin, they apply their skepticism selectively. They apply it to undercut only ideas they reject, especially ideas about God. They make a tacit exception for their own worldview commitments.

� 2015 Nancy Pearcey. Finding Truth: 5 Principles for Unmasking Atheism Secularism, and Other God Substitutes published by David C Cook. All rights reserved.

Image by Palmiped at en.wikipedia [CC BY 3.0], from Wikimedia Commons.