Reading Time: 7 minutes

In my last post, we looked at four (bad) arguments for the existence of God presented by Tim Keller in Chapter 8 of The Reason for God. I call them the Argument from Inexplicability, the Argument from Fabricated Probabilities, the Argument from Wishing, and the Argument from Regularity. As I’ve often pointed out, not only are arguments like these untenably weak, but even if they weren’t they would still fail to establish which God we are discussing.

Even if we decided the universe had to have a supernatural cause, that still wouldn’t take us the other 17 steps getting us from “something supernatural” to the Christian God specifically. None of these necessarily point to a singular benevolent paternal being who communicated through a specific infallible religious text that must be interpreted only by men who hold to trinitarian Christian theism. All of those things are non-negotiables for Keller, but he wisely keeps those details to himself.

He gives one more argument at the end of Chapter 8 which I will call The Argument from Misunderstanding How Evolution Works. He seems to feel this is a gotcha for atheists, exposing the weaknesses of both philosophical naturalism and of the theory of evolution itself. He conflates those two things in a way which betrays his own deep distrust of the science behind evolutionary theory. He uses the term “evolutionary theorists” to signify his antagonists, which is significant coming from a man who just got finished telling us his religious tradition doesn’t pit faith against science.

For the record I think God guided some kind of process of natural selection, and yet I reject the concept of evolution as All-encompassing Theory. (p.98)

What does that even mean? Is it natural selection or is it supernaturally directed? They mean very different things. And what does he mean by All-encompassing Theory?

Misunderstanding Evolution

Keller seems to oversimplify the mechanisms that produced the millions of species now running and swimming and flying around on our planet:

…the school of evolutionary biology…claims everything about us can be explained as a function of natural selection. (p.140)

That’s not exactly correct. Evolutionary biology doesn’t claim that everything about us can be explained as a function of natural selection. That is one of the forces at work in evolution, but he fails to mention the other, and that’s the one most responsible for our world’s amazing biodiversity.

People often speak of two interacting forces—one creative and the other destructive—working together to make evolution happen: mutation and natural selection. Mutations occur mostly at random—although some happen as a direct response to the influence of an organism’s surrounding environment—and they produce the limitless biological diversity that so richly populates our ecosystem. Those mutations that favorably adapt an organism and its offspring to the ever-changing environment tend to be propagated into the next generation because, at least eventually, those mutations which do not favorably adapt an organism to its environment don’t make it into subsequent generations, thus eliminating those traits over a long period of time (that detail is important).

That’s the part we call natural selection. We talk about nature “choosing” to reward one trait over another as if it were an intelligent force because after each disadvantageous trait is eliminated, this process will appear more and more purposeful in retrospect. But nature isn’t really thinking at all, which explains why so many irrational and unhelpful biological traits come and go before each new outgrowth of speciation is complete.

Why does this matter? It matters because whenever people conflate those two forces the way Keller does, the apparent purposefulness of natural selection tends to obscure the randomness of the process of mutation, leading people to think that evolution moves in a straight line. But it doesn’t. Evolution is a stochastic process in which living things can morph and develop into almost any imaginable direction, logical or otherwise. Not every trait evolution produces is beneficial to the organism, nor does each one necessarily help it survive or reproduce. Only time will tell whether or not each development will provide a benefit to the organism.

Evolutionary biologists understand this, but Keller doesn’t. He seems to think evolutionary theory necessitates that each new biological development must be beneficial to the organism’s survival, leading him to demand things from evolution which it will never reliably provide, things which no one who understands how evolution works would expect from it.

For example, despite the usefulness of our highly evolved brains, there is nothing within the evolutionary pressures of nature which would ensure the ideas and beliefs they conjure bear any correspondence to reality. Clearly nothing stops humans from believing highly irrational ideas—just go look at your Facebook feed. Keller is convinced this constitutes an insurmountable philosophical problem for us.

Why Our Minds Don’t Have to Be Reliable

Keller argues that those of us who accept evolution should be scandalized by the fact that natural selection cannot guarantee that our minds accurately perceive everything about the world around us.

Evolution can only be trusted to give us cognitive faculties that help us live on, not to provide ones that give an accurate and true picture of the world around us. (p.141)
This is a huge Achilles’ heel in the whole enterprise of evolutionary biology and theory. (p.143)

Here again we see this disdain for science cropping up after he has repeatedly insisted his faith doesn’t militate against human reason. Like his hero C.S. Lewis before him, he wishes to argue that his faith is a reasonable faith–contrary to the apostle Paul’s refrain that spiritual realities operate on a different plane, making any appeal to human reasoning futile. But unlike C.S. Lewis, Keller is a Calvinist and a presuppositionalist, which makes him highly tentative about accepting the conclusions of modern science.

Lewis maintained that Adam and Eve were metaphors, but Keller’s theology won’t allow that. He admits elsewhere that we must see Adam and Eve as a literal historical couple because the Bible says they were. Anything else is unacceptable. Despite his own attempts to present the Christian faith as compatible with modern science, he simply cannot stay the course, and eventually falls back on an anti-scientific position.

Read: “Faith and Reason Are Not Really Friends

Getting back to our main point, Keller argues that naturalistic evolution cannot possibly guarantee that anything we think corresponds to reality or truth. Taking his cue from Reformed darling Alvin Plantinga, he argues that naturalism is a self-defeating ideology because it cannot guarantee that minds produced by purely natural forces can accurately perceive truth.

If our cognitive faculties only tell us what we need to survive, not what is true, why trust them about anything at all? (p.142)

First of all, I cannot help but point out once again his error in thinking that evolution can only give us that which pertains to raw survival. That point isn’t essential to this line of argumentation, but it’s a recurring annoyance which bears repeated correction. Most of what our creative brains produce has little or nothing to do with survival—things like art, music, film, scientific exploration, philosophy, and TikTok. We do so many things that make us happy but aren’t required for survival at all.

It seems that evolutionary theorists have to do one of two things. They could backtrack and admit that we can trust what our minds tell us about things, including God…Or else they could go forward and admit that we can’t trust our minds about anything. (p.141-142)

Keller thinks it should be a problem for “evolutionary theorists” to discover that we cannot rely on our own minds to tell us what is true and what is not. Perhaps he thinks this is a problem because of the aforementioned misunderstanding about how natural selection works. To him and Plantinga, this seems to be a logical defeater built into naturalism, invalidating it from within.
But who says we ever expected our minds to be infallible guides to truth? I’m sure there are people out there who go that far (Ayn Rand and other logical positivists come to mind), but there is nothing inherent within naturalism which necessitates jumping to that conclusion.

…it is ultimately irrational to accept evolutionary “naturalism,” the theory that everything in us is caused only by natural selection. If it were true, we couldn’t trust the methods by which we arrived at it or any scientific theory at all.  (p.143)

No, that’s not correct. The scientific method contains within itself a process for sifting through the false beliefs we accumulate (including the ones we have about science itself) so that we don’t have to rely on the ability of our own minds to arrive at a true picture of the world around us. Skeptics and Christians essentially agree that we cannot trust ourselves to grasp reality in an unbiased manner, but then we part ways when choosing what will save us from the limitations of our own imperfect perceptions. For the skeptic, that savior is rigorously-tested, always-improving-upon-itself empirical observation (i.e. the scientific method). For Keller, it’s the Bible.

End of discussion.

Read: “What Will Save Us from Our Own Subjectivity?

We don’t need our minds to be perfectly reliable the way that Keller suggests, and yet our minds successfully accomplish the most amazing things. Who didn’t marvel nearly a decade ago when we first remotely landed a one-ton bucket of bolts and circuit boards on Mars that we launched nine months earlier on a 350-million-mile trek across the solar system? Clearly our minds can accomplish a great deal, especially with the help of the intellectual tools we have developed like math and science.

Keller knows these tools are effective, and I would argue that he trusts them to produce reliable results every single day of his life—right up until the moment one of them suggests there’s something wrong with his religious beliefs. Now suddenly science is something to hold at arm’s length.

It’s incorrect to say that philosophical naturalism and evolutionary theory demand we believe our minds are reliable. That’s why we invented science in the first place. We knew too well how good we are at fooling ourselves.

Skipping Steps

Throughout this book, Keller’s approach to apologetics suffers from the same weakness that I see among all presuppositionalist apologists. Following the lead of Cornelius Van Til, who invented this approach, Keller spends the majority of his time engaging in an “internal critique” of those worldviews which he would like to discredit rather than demonstrating why his own should be chosen instead. In essence, presuppers focus entirely on invalidating the other guy’s perspective without doing much to establish the validity of their own.

Finding gaps in my philosophical framework doesn’t automatically score points for your own. You have to provide evidence that establishes how yours performs better at seeing the world the way it actually is. I have never seen this done because at this stage in the discussion they’re too focused on guilting you for needing evidence at all.

Keller thinks if he can show philosophical inconsistencies in other people’s ways of thinking, that automatically means his own wins. But it’s not that simple. Somewhere along the way, he has to show us real reasons to believe this stuff. It won’t do to keep saying that if we can’t explain how things happen, that means a Giant Invisible Person had to have done it. You’re skipping too many steps.

[Image Source: Imgur]

If you’re new to this column, be sure to check out The Beginner’s Guide for 200+ articles categorized topically on a single page.

Avatar photo

Neil Carter is a high school teacher, a father of four, and a skeptic living in the Bible Belt. A former church elder with a seminary education, Neil now writes mostly about the struggles of former evangelicals...