This is a defence of externalism about knowledge and also about justification. In this paper, I argue that an important virtue of externalism about these notions is that externalism about justification helps to explain the value of (i.e., importance of) knowledge. I also develop and expand upon some of my earlier arguments for externalism that drew upon what's now known as 'morally loaded cases'. The virtue of externalism is that it's the only view that can both allow for certain kinds (...) of categorical normative requirements while also vindicating the idea that we ought to be guided by the beliefs that we ought to have. (Internalists either have to deny that we ought to be guided by the beliefs that we ought to have (which isn't very internalist!) or, failing that, revise our views about the existence of certain kinds of categorical requirements and tell us that we ought to be guided by our beliefs to do evil things (which isn't very nice!).). (shrink)