According to one prominent critique of mainstream epistemology, discoveries about what it takes to know or justifiedly believe that p can’t provide the right kind of intellectual guidance. As Mark Webb puts it, “the kinds of principles that are developed in this tradition are of no use in helping people in their ordinary epistemic practices.” In this paper I defend a certain form of traditional epistemology against this “regulative” critique. Traditional epistemology can provide—and, indeed, can be essential for—intellectual guidance. The reason is that, in many cases, how you should proceed intellectually depends on what you already know or justifiedly believe: how you should treat counterevidence to your beliefs, for example, can depend on whether those beliefs count as knowledge. Therefore, to get guidance on how to proceed intellectually, it will often be essential to be able to figure out what you know or justifiedly believe. And to do that it will often be helpful to try to figure out what it takes to count as knowledge or justified belief in the first place. To do this is precisely to engage in mainstream epistemology.