Carla asked:

What’s the difference between Naturalism and Materialism?

Answer by Danny Krämer

That question just jumped onto me. Here is my attempt to answer it. The easy part is materialism: Materialism is a position in ontology that states, that everything there is is matter. Of cause now you have to explain what you mean by matter and how some objects that make always trouble – like the mind, numbers, values – can be material. You can be a reductive materialist. That means, you reduce non-material things to material things. For example, you reduce mental events to physical events in the brain. But you can also be a non-reductive materialist. That means, you still believe that everything is matter but that you will not reduce mental talk to physical talk. A mental event, for example, is then not just a brain state but the brain state plus some external properties like its origin.

Now it is true that most of the naturalists are materialists. But modern naturalism was introduced by Willard van Orman Quine as an epistemological thesis. He said, ‘There is no first philosophy.’ That means we do not need philosophy to justifiy our scientific practice – as for example Descartes wanted to do. All we need to know something about the world is science. If we ask what exists, we should ask what our best scientific theories postulate. This is an epistemological point. But it has ontological consequences. When we ask our sciences what exists we get first of all the answer of physics. There are fields or particles and basically everything is made out of it. And then you have to do your ontological homework as mentioned in the last paragraph.

But a naturalist need not be a materialist. Actually, he is forced to give up materialism if there is good scientific reason to. If we would gather scientific evidence that there is another substance than matter then the naturalist must abandon his belief that everything is made of matter.