In “Is the Only Real Knowledge Scientific Knowledge?” I argued that scientism—the belief that science is the only source for real and objective knowledge—is a self-referentially incoherent belief. It’s not empirically verifiable or quantifiably measurable, and thus is not subject to scientific inquiry. But if it’s not scientific knowledge, then according to its own principles it’s not real knowledge, and so it refutes itself.
Recently I presented this argument in a radio interview and it gave rise to a very interesting follow-up question: “If scientism is so blatantly self-contradictory, why do so many intelligent people still believe it?”
Atheist philosopher Alex Rosenburg gives an answer:
The phenomenal accuracy of [physics’] prediction, the unimaginable power of its technological application, and the breathtaking extent and detail of its explanations are powerful reasons to believe that physics is the whole truth about reality.
Put simply, the unparalleled predictive and technological success of science gives us good reason to think it’s the only source of knowledge about what is real.
But is this a good argument? Let’s think it through and see.
We can start by taking the reasoning embedded in the argument and comparing it to other things. To use an example from philosopher Edward Feser, since metal detectors have had great success in detecting metal, should we conclude that there is nothing else to reality besides metal?
The question shows the absurdity of the logic. We recognize its fallacious character because we see that the conclusion, “There is nothing more to reality than metal,” doesn’t follow from the premise, “The metal detector is successful at detecting metal.”
The metal detector is incapable of detecting non-metallic elements, and thus will not be successful at detecting things not made of metal. But this says nothing about whether or not non-metallic elements exist. It’s simply a manifestation of the limitations of the metal detector’s powers. To restrict reality only to that which the metal detector can detect is to confuse method with reality.
Consider another example: an infrared camera. Such a gadget detects energy (heat) and converts it into an electronic signal, which then produces a thermal image on a video monitor—very useful, for instance, for tracking people in low-light situations. Since the infrared camera successfully detects the heat that people generate, are we to conclude that heat is all there is to the reality of human beings?
The same absurdity is present in Rosenberg’s argument for scientism. The modern methods of science are by nature restricted to detecting things within the boundaries of physical reality. Physics is ordered to those things in the natural world susceptible to mathematical modeling, which is what makes precise predictions and technological application possible. But just because these methods are successful in giving us knowledge about the physical world and its empirical and quantifiable aspects, it doesn’t follow that physical reality is the only reality. There may be other things that constitute reality that are outside what science can detect. This says nothing about whether such things exists—it’s merely a manifestation of the inherent limitations of the detecting powers of science.
So, if the only evidence that you bring to support the success of science is the knowledge it has given us of the physical world, then of course science is going to be one long success story. That’s what science does. But to conclude from that success that only science gives us knowledge of all reality is like saying my 4.0 grade point average proves I’m a genius in all subjects even though I’ve only taken classes in which I knew I would do well. Sure, I’m going to seem pretty smart about things if all I’m offering for evidence are my grades in classes that are my specialty. But take into consideration the other classes that I intentionally avoided and my knowledge may not be so comprehensive after all.
Similarly, science may seem comprehensive in the knowledge it can give us about reality if we’re considering only physical reality. But not only is science not good at detecting non-physical realities—it can’t do it at all! It can’t tell us the first thing about whether those realities exist or don’t exist. If they do exist, science is not comprehensive in what it says about reality.
Now, your atheist friend might object: “Your analogies don’t work because they detect only part of reality. The metal detector detects only metal. The infrared camera detects only heat. Your grade point average only reflects your knowledge. Science detects the whole of reality.”
But this response simply begs the question, for the belief that what science describes is the whole of reality is what we’re debating in the first place. Science may be very successful in its predictive power and technological applications, but when you think it through, this is not a good reason to conclude that what it detects exhausts the whole of reality.