It is often said that belief aims at truth. I argue that if belief has an aim then that aim is knowledge rather than merely truth. My main argument appeals to the impossibility of forming a belief on the basis of evidence that only weakly favours a proposition. This phenomenon, I argue, is a problem for the truth-aim hypothesis. By contrast, it can be given a simple and satisfying explanation on the knowledge-aim hypothesis. Furthermore, the knowledge-aim hypothesis suggests a very plausible account of what it takes for evidence to be sufficiently good to make belief possible. I offer several further considerations in favour of the knowledge-aim hypothesis, and deal with objections. Although the main point of the paper is not to defend the view that belief has an aim, but to adjudicate between accounts of what that aim is, my argument nevertheless requires some attention to the motivation for attributing an aim to belief in the first place. In particular, I will explain an important advantage that this view has over the view that belief is not aim-directed, but only subject to a constitutive norm.