 The arguments of the previous section are a priori in at least the broad sense of that term (the psychologists’ sense): They depend on general conceptual considerations and armchair folk psychology rather than on empirical research. To these might be added the argument, due to Boghossian (1989) that “externalism” about the content of our attitudes (the view that our attitudes depend constitutively not just on what is going on internally but also on facts about our environment; Putnam 1975; Burge 1979) seems to problematize introspective self-knowledge of those attitudes. This issue will not be treated here, since it is amply covered in the entries on  externalism about mental content  and  externalism and self-knowledge.