The shortest definition of materialism is that it holds that everything in the universe is matter and its motions. Hence for materialists, the “hard problem” is to explain the existence of consciousness. Whereas,for what are called “idealists”, the hard problem is the existence of matter. Does it have existence independently of mind? Then there are those who think that mind and matter both exist, independently of one another.
Here is an anecdote about the philosopher-scientist Rupert Sheldrake:
“The British scientist Rupert Sheldrake told me about a talk he gave to a group of scientists who were working on animal behaviour at a prestigious British University. He was talking about his research on dogs that know when their owners are coming home, and other telepathic phenomena in domestic animals. The talk was received with a kind of polite silence. But in the following tea break all six of the senior scientists who were present at the seminar came to him one by one, and when they were sure that no one else was listening told him they had had experiences of this kind with their own animals, or that they were convinced that telepathy is a real phenomenon, but that they could not talk to their colleagues about this because they were all so straight. When Sheldrake realised that all six had told him much the same thing, he said to them, “Why don’t you guys come out? You’d all have so much more fun!” He says that when he gives a talk at a scientific institution there are nearly always scientists who approach him afterwards telling him they’ve had personal experiences that convince them of the reality of psychic or spiritual phenomena but that they can’t discuss them with their colleagues for fear of being thought weird.”
And here, in a nutshell, is the great Sheldrake explaining why science is so badly constipated by materialist assumptions. Science as a world view has come to constrict the process of open-minded inquiry, which is what science ought to be. Science is a process, not a wholly-owned subsidiary of dogmatic materialism.
For a better explanation of Sheldrake’s views, see his book The Science Delusion.