I can’t say how many times I’ve heard this phrase from theists. It is, at the same time true and, as an argument, meaningless. Many theists must think it proves something, for it’s asserted as if it defeats any argument against theism or, at least, against deific omniscience.

Of course, it ends no argument. It only demonstrates a lack of understanding of science or a commitment to God-of-the-gaps theology.

Certainly there are many phenomena in the universe no one can explain. In fact there are more we cannot explain than ones we can. Even those we can explain have beneath them ever finer definitions or explanations of reality, for answers force our minds to further questions. Our ancient quandary about why lodestone pointed north was answered at a simple level a couple of millennia ago. But that only introduced further questions, including much later the relationship of magnetism and electricity. The iterations continued further; we now struggle with the unknowns that cause the earth’s magnetic poles to switch positions. How could we question the infinitesimal difference in proton and neutron mass (a neutron weighs 1.6749286 X 10^-27 kg; a proton 1.6726231 X 10^-27 kg) if Ernest Rutherford had not hypothesized these subatomic particles a century ago? Knowledge builds on knowledge.

The history of science is chock full of sequentially deeper and deeper explanations. The history of religion is not, for explanations are “revealed” by God, not tested to tease causes out of observations. In fact, the nature of science as a human attitude toward inquiry yields what might be called descending levels of explanation, levels that are expected to be never ending. In fact, you could say that scientific inquiry continually exposes even further ignorance. In other words, it is not just that “there are things that science can’t explain,” it is that science itself is the most prolific source of things it cannot explain!

(The theist blunder is reminiscent of creationists’ taunt that no “missing link” has been found between humans and an earlier life form. Of course, when evidence of an evolutionary mid-point is discovered, that creates two more missing links. As others are unearthed, the remaining missing links are multiplied, providing creationists an unending supply of “proof” against biological evolution.)

It is an elementary error to assume that the inability of science to explain everything is somehow proof that religion can. Theists do not claim they have the answers themselves, of course, but that their assumed deity does have (or is) the repository of all possible explanations to all possible questions. Were that to be true, the explanations of science definitely come up short. Funny, though, that through the centuries religious beliefs about the physical world have been supplanted by research-based conclusions. The reverse has not occurred. Joshua didn’t make the sun stand still; a star didn’t reposition itself over a manger; a spherical world does not have four corners.

The problem with religion is that its claims are not falsifiable. While science discards a hypothesis for which there are no methods of inquiry that would show it to be untrue (if it is), the epistemology of religion takes a very different path. Religion doesn’t need science, for it has all the answers it needs, so allegations from a preferred authoritarian source (for Protestant Christians, the Bible; for Catholic Christians, the Church and Bible; for Muslims, the Koran and Hadith) are treated as unquestioned truth whether there is evidence or not. Unfalsifiable claims are not seen with skepticism, but with ingenuous enthusiasm, as if mysteries are part of the appeal. Thus a claim that there is a celestial teapot (thanks to Bertrand Russell), because it is unfalsifiable, is in the same category as a claim that there is a Santa Clause, Easter Bunny, or Jehovah. There is no way to prove any of these untrue.

The ancients, out of ignorance, fear, and powerlessness, filled in the gaps of their understanding with all manner of unseen spirits. Lightning was due to static discharge rather than angry gods, rainbows due to refraction not a divine promise, plague due to rats not retribution for sin. Knowledge caused these gaps to shrink, but not to disappear. Theists have a long tradition of ascribing to God whatever gaps remain at a given time. Even a century and a half after Henry Drummond spoke of the concept, theists still fall back on the mindless phrase that began this essay, as if what we still don’t know shows there must be a supernatural cause, one that—whoops—cannot be disproven!

In holding fast to their “argument from ignorance,” theists conveniently overlook that it means “my guess is superior to your recognition that there is no evidence.” Had this bizarre position not been largely overcome by those strong or foolish enough to blaspheme, the unending stream of scientific discovery would have been throttled even more than it was. “I don’t know what causes plagues, but let’s study it” would have been beaten down by “plagues are punishments from God, so what’s to study?”

Biblical symbolism unintentionally exposes the religious mindset when it describes the first sin, the ostensible event that turned a perfect creation into a punishing existence: Adam and Eve consumed a fruit that—horrors!—exposed them to knowledge. Six thousand years later, millions of otherwise intelligent theists fight scientific discovery whenever it threatens to countervail their faith, fearing to make their vengeful God mad again. One need only consider the current dispute over “intelligent” design.

So, are there things that science cannot explain? Of course. And there always will be. Science exists because there are not only things yet unexplained, but beyond them, questions not yet asked. Thus, the perfection of human knowledge will always be a receding horizon. We humans, so little removed from our evolutionary origins, must come to terms with the fact that many—nay, most—understandings are beyond us. That does not make them supernatural, it simply makes them unknown.