Why Double-Check?

Abstract Can you rationally double-check what already know? In this paper, I argue that can. Agents can know something is true and it at the very same time. defend my position by considering a wide variety of cases where agents their beliefs to gain epistemic improvements beyond knowledge. These include certainty, resilience, sensitivity error. Although phenomenon widespread, proposal faces two types challenges. First, some have defended ignorance norms, on which are only allowed inquire about things they don't know. Second – motivated strong conceptions belief or pragmatic encroachment argued double-checking destroys these competing views fail capture both value many reasons why might double-check. Moreover, rely overly assumptions inquiry, knowledge, requires. Finally, marshal linguistic data in favor compatibility knowledge double-checking.