Social Externalism and Physical Externalism about Content

The strongest argument for social externalism derives from the rule-following considerations that motivate a social theory of conceptual content. The best argument for physical externalism goes back to Putnam’s twin earth thought experiment. The aim of this paper is to point out that these two sorts of externalism give contradictory accounts of what determines the con-ceptual content of our beliefs and individuates them. According to physical externalism, the physical environment is sufficient to perform that task ow-ing to suitable causal relations. According to social externalism, the con-ceptual content of our beliefs is determined by us owing to certain social interactions. Possible strategies to reconcile both these accounts are consid-ered. 1