Do Descartes, Locke, and Hume have an internalist or externalist view of epistemic justification? Internalism is, roughly, the view that a belief that p is justified by a mental state, such as the awareness of evidence. By contrast, externalism is, roughly, the view that a belief that p is justified by facts about the belief-forming process, such as the reliability of the belief-forming process. I argue that they all think that the awareness of evidence is required for justification, but none (...) of them think that the awareness of evidence alone is sufficient for justification. Similarly, I argue that they all think that reliability of the belief-forming process is required for justification, but none of them think reliability alone is sufficient for justification. So, neither a fully internalist position nor a fully externalist position adequately captures their views of justification; rather, both the supporting evidence and the reliability of the belief-forming process explain why we should hold those beliefs, and hence explain why those beliefs are justified. Thus, they each have a partly internalist, partly externalist view of justification. (shrink)