What do Layers Matter?

If Layers matter for anything, they matter for this: a theory might be true, useful, and valuable, but there might be another theory that can sit right where the first theory is that is also true, useful, and valuable. It is a way of looking at the world that preserves the size of the world. So that when asked a question we can respond, "in a sense X, but in other senses, I don't know."