What each of us has is direct experience. So does every other animal, they have some kind of experience. A bee sees the world differently than we do because it is a different organism. And other organisms just try to work their way around the world of their experience. Humans, as far as we know, are unique in the animal world in that they're reflective creatures. That is, they try to make some sense out of their experience.
There are all kinds of ways of doing this: some are called myth, some are called magic, some are called religion. Science is a particular one it's a particular form of trying to gain some understanding of our experiences, organize them. It relies on evidence, coherent argument, principles that have some explanatory depth, if possible. And that mode of inquiry, which has been, particularly in the last couple hundred years, extremely successful, has its scope and its limits. What the limits are we don't really know.
In fact, if you look at the history of science seriously, in the seventeenth century there was a major challenge to the existing scientific approach. I mean, it was assumed by Galileo and Descartes and classical scientists that the world would be intelligible to us, that all we had to do was think about it and it would be intelligible.
Newton disproved them. He showed that the world is not intelligible to us. Newton demonstrated that there are no machines, that there's nothing mechanical in the sense in which it was assumed that the world was mechanical. He didn't believe it in fact he felt his work was an absurdity but he proved it, and he spent the rest of his life trying to disprove it. And other scientists did later on. I mean, it's often said that Newton got rid of the ghost in the machine, but it's quite the opposite. Newton exorcised the machine. He left the ghost.
And by the time that sank in, which was quite some time, it just changed the conception of science. Instead of trying to show that the world is intelligible to us, we recognized that it's not intelligible to us. But we just say, Well, you know, unfortunately that's the way it works. I can't understand it but that's the way it works.' And then the aim of science is reduced from trying to show that the world is intelligible to us, which it is not, to trying to show that there are theories of the world which are intelligible to us. That's what science is: It's the study of intelligible theories which give an explanation of some aspect of reality.
Scientists typically don't study the phenomenal world. That's why they do experiments. Our phenomenal world is way too complex. If you took videotapes of what's happening outside your window, the physicists and chemists and biologists couldn't do anything with it. So what you try to do is try to find extremely simple cases that's called experiments in which you try to get rid of a lot of things that you guess are probably not relevant to finding the main principles. And then you see how far you can go from there the fact is, not very far.
When people talk about what science tells you about human affairs, it's mostly a joke. Incidentally, I don't think religion tells you very much either. So it's not that science is displacing religion, there's nothing to displace.