The Gettier problem has stymied epistemologists. But, whether or not this problem is resolvable, we still must face an important question: Why does the Gettier problem arise in the first place? So far, philosophers have seen it as either a problem peculiar to the concept of knowledge, or else an instance of a general problem about conceptual analysis. But I would like to steer a middle course. I argue that the Gettier problem arises because knowledge is a thick concept, and (...) a Gettier-like problem is just what we should expect from attempts at analyzing a thick concept. Section 2 is devoted to establishing the controversial claim that knowledge is thick, and, in Sect. 3, I show that there is a general problem for analyzing thick concepts of which the Gettier problem is a special instance. I do not take a stand on whether the Gettier problem, or its general counterpart, is resolvable. My primary aim is to bring these problems into better focus. (shrink)