Chisholm is perhaps best known for his work in epistemology. Though the details of formulation steadily changed, Chisholm’s fundamental position in epistemology remained constant. Chisholm took it as a starting point for his epistemological theorizing that we do have knowledge of the external world. In addition, Chisholm accepted further anti-skeptical doctrines concerning knowledge by memory of the past, and a priori knowledge of some necessary truths. He did not assume that he could refute skepticism. Rather, he understood the central project of epistemology to be the project of showing in detail how it is possible for us to have quite a lot of the knowledge that, in our reflective moments, we take ourselves to have. In adopting this stance, he seems to have been influenced by Moore as well as some of his teachers at Brown and Harvard.