show that it is “reasonable” in terms of our ultimate beliefs about how things really are. But what is meant by the word explain? We accept something as an explanation when it shows how an unexplained fact fits into the world as we already understand it. Explanation is related to the framework of understanding we inhabit, the firm structure of beliefs we never question, our picture of how things really are. Explanation puts a strange thing into a place where it fits and is no longer strange. Thus