This is a Guest Post by Frank Bellamy, a reader and content manager for the eMpirical, the newsletter for the Secular Student Alliance. He recently wrote an interesting article on why Humanists should not deliver invocations, but today he’s going to talk a bit about philosophy. So, discuss your hearts out while I’m away!

Evils of constructive empiricism

Philosophers routinely entertain and foster ideas which are not only stupid, but also an affront to science: dualism, intelligent design, qualia, the list goes on. Another item on that list that I have only recently discovered is constructive empiricism. That phrase may sound harmless enough, after all, scientists like empirical evidence, and being constructive is good, right? It’s anything but harmless when one looks at its meaning. According to the Stanford encyclopedia of philosophy, “the constructive empiricist holds that science aims at truth about observable aspects of the world, but that science does not aim at truth about unobservable aspects.” In other words, science gives us no reason for thinking that the unobservable constructs posited by scientific theories actually exist.

A few concrete examples may be useful here. According to the constructive empiricist, we have no good reason to think that atoms exist. After all, no one has ever seen, heard, felt, tasted, or smelled an atom. Atoms may be a useful computational tool for determining what will happen when we mix two substances together, but that is not a reason for attributing actual existence to them. Scientists may even believe that atoms exist, but if they do they go beyond what the evidence warrants.

Evolutionary biologists are in equal trouble. Since we can’t actually observe history, we have no reason for believing historical claims. The idea that humans and chimpanzees share a common ancestor more recently than humans and cats may be useful for explaining and predicting various features of the genomes, morphology, or cognitive capacities of these species, but that is not a reason for thinking that any of these species share common ancestors, or indeed that they even have ancestors at all.

To use a more every day example, I have a theory that Jen believes that the christian god does not exist. This theory may be useful in predicting what sorts of things Jen will write on her blog in the future. It allows me to predict, for example, that the next time Jen writes about some amazing new scientific discovery, she will explain it in naturalistic rather than theological terms. But according to the constructive empiricist, that is no reason for thinking that Jen actually has such a belief. Since I can’t directly observe any of Jens beliefs, I am completely unwarranted in believing that she has beliefs at all. So much for theory of mind being a positive aspect of human cognition.

Lets set aside the fact that constructive empiricism entails that scientists are liars and consider its practical implications for science. A scientist who believes in constructive empiricism doesn’t have to waste time considering such irrelevant questions as whether his pet theory is true or not, or how it relates to other theories in other parts of science. All that matters is whether his pet theory can account for the available data.

One implication of this is that it completely undermines the motivation most scientists have for doing science in the first place. Scientists don’t just want equations and models that predict data, we want to understand whatever phenomenon we have chosen to study. We want to know what’s actually going on in the world. We want to know how what we’re doing relates to other parts of science. If constructive empiricism is true, then we are deluding ourselves. Science isn’t in the business of telling us how things really are.

Another implication of constructive empiricism is that it doesn’t really matter how well theories in different domains of science match up with each other. If we explain the movement of objects on earth in terms of forces and masses, and the movement of objects in the sky in terms of Ptolemy’s spheres, so long as we can predict the data that’s ok. If we have physically, neurally, or evolutionarily implausible theories of human cognition, that’s ok, so long as we can predict the behavioral data. If scientists were to truly adopt this view, it would change the face of science forever, and not for the better.

And why would I, a grad student with many other non-philosophical demands on his time be worrying about constructive empiricists you may wonder? It’s because I’ve recently discovered that my adviser is one. Frack me.