Scientists do their work by assuming that every phenomenon can be reduced to a material, mechanistic cause and by excluding any possibility of nonmaterial explanations. And the materialist assumption works really, really well—in detecting and quantifying things that have a material or mechanistic explanation. Materialism has allowed us to predict and control what happens in nature with astonishing success. The jaw-dropping edifice of modern science, from space probes to nanosurgery, is the result.

But the success has gone to the materialists’ heads. From a fruitful method, materialism becomes an axiom: If science can’t quantify something, it doesn’t exist, and so the subjective, unquantifiable, immaterial “manifest image” of our mental life is proved to be an illusion.

Here materialism bumps up against itself.