According to Chisholm, epistemology consists of Socratic inquiry into the questions “What can we know?” and “What are the criteria of knowledge?” He thought that a puzzle faces anyone who attempts to answer these questions. It appears that to answer the first question, one needs a criterion to distinguish between things that are known and things that are not known. That is, one needs an answer to the second question. But to have an answer to the second question, he thought, one needs a list of the things one knows so that one can identify the features that distinguish knowledge from its opposite. That is, one needs an answer to the first question. Lacking such an answer, Chisholm feared, one would not be in a position to be confident that any proposed criterion of knowledge was correct. Chisholm calls those who think that they have an answer to the second question that they can use to answer the first “methodists” and those who think that they have an answer to the first question that they can use to answer the second “particularists.” Chisholm himself was a particularist, yet he claimed that he had no argument to offer against methodism or against the view that neither question could be answered without a prior answer to the other. In a number of places he said that the problem of the criterion could be answered only by begging the question.