What Science Can’t Prove

by Greg Koukl

If science can’t even disprove the existence of unicorns, how can it disprove the existence of God?

I often hear the comment, “Science has proved there is no God.” Don’t ever be bullied by such a statement. Science is completely incapable of proving such a thing.

I’m not saying that because I don’t like science, but rather because I know a little about how science works. Science operates on induction. The inductive method entails searching out things in the world and drawing generalized conclusions about those things based on observation. Scientists can only draw conclusions on what they find, not on what they can’t find.

Science, by its very nature, is never capable of proving the non-existence of anything.

For example, can science prove there are no unicorns? Absolutely not. How could science ever prove that unicorns don’t exist? All science can do is say that scientists may have been looking for unicorns for a long time and never found any. They might therefore conclude that no one is justified in believing that unicorns exist. They might show how certain facts considered to be evidence for unicorns in the past can be explained adequately by other things. They may invoke Occam’s Razor to favor a simpler explanation for the facts than that unicorns exist. But scientists can never prove unicorns themselves don’t exist.

Since science, by its very nature, is never capable of proving the non-existence of anything, one can never accurately claim that science has proven God doesn’t exist. That’s a misuse of the discipline. Such a claim would require omniscience. The only way one can say a thing does not exist is not by using the inductive method, but by using a deductive method, by showing that there’s something about the concept itself that is contradictory.

I can confidently say for sure that no square circles exist. Why? Not because I’ve searched the entire universe to make sure that there aren’t any square circles hiding behind a star somewhere. No, I don’t need to search the world to answer that question.

The concept of square circles entails a contradictory notion, and therefore can’t be real. A thing cannot be a square and be circular (i.e., not a square) at the same time. A thing cannot be a circle and squared (i.e., not a circle) at the same time. Therefore, square circles cannot exist. The laws of rationality (specifically, the law of non-contradiction) exclude the possibility of their existence.

This means, by the way, that all inductive knowledge is contingent. One cannot know anything inductively with absolute certainty. The inductive method gives us knowledge that is only probably true. Science, therefore, cannot be certain about anything in an absolute sense. It can provide a high degree of confidence based on evidence that strongly justifies scientific conclusions, but its method never allows certainty.

If you want to know something for certain, with no possibility of error–what’s called apodictic certainty in philosophy–you must employ the deductive method…


Stand to Reason | What Science Can’t Prove