What is curiosity? An attractive option is that it is a desire to know. This analysis has been recently challenged by what I call interrogativism, the view that inquiring attitudes such as curiosity have questions rather than propositions as contents. In this paper, I defend the desire-to-know view, and make three contributions to the debate. First, I refine the view in a way that avoids the problems of its simplest version. Second, I present a new argument for the desire-to-know view (...) that focuses on ascriptions of the form ‘S is curious to φ’, which, despite their prevalence, have been ignored in the literature. Third, I examine the central motivation for interrogativism—the argument from metacognition, according to which animals can be curious yet do not have the metacognitive capacities required by desires to know—and argue that it rests on questionable assumptions about desires and attitude ascriptions. (shrink)