I may take a while, but I do eventually circle back to threads of thought that I start however long ago. Six years ago I argued that materialism was necessary and complete -- that an honest inquiry would conclude that everything that exists is material. Such a claim is greeted by philosophers with eye-rolling condescension, and most laypeople reject the notion as far too sweeping. I nonetheless believe I can make a convincing argument.
First of all, let me clear up some confusion. Materialism is not the same as saying that science already knows everything that can exist. It seems odd, but when I talk about materialism some people seem to confuse that with tacit acceptance of the Standard Model, which is a theory about all the kinds of particles believed to exist. It may be right or it may be wrong, but that has nothing to do with materialism. All that materialism says is that anything new discovered by science will be material. If dark matter is real then it's made of something.
Materialism is also not the same as saying that science is the only way to study the world. I'm a big fan of science, don't get me wrong. It says so right in my blog banner. But there are many legitimate forms of inquiry that are not amenable to scientific methods. The fact that we live in a material universe has no effect on the study of art and literature. Indeed those works were created by humans with physical brains, but the workings of the brain are hidden and its mechanisms are mysterious, so the physical sciences can be of no help here.
Likewise, materialism doesn't deny the existence of emotions or ideas. "What about love?" people always ask. Yes, love exists. Of course it exists. The question is: how do we know that love exists? We know it because we observe its effects. We see it demonstrated in the physical world as acts of compassion between people. Saying the words or feeling the feeling subjectively isn't enough. The stalker may feel deeply that he loves his victim, but we can determine by his actions that he's mistaken. It's this objective aspect of love, and other feelings and ideas, that grounds it and makes it meaningful. Stripped of its material aspects, love ceases to exist.