Two grades of internalism (pass and fail)

Internalism about mental content holds that microphysical duplicates must be mental duplicates full-stop. Anyone particle-for-particle indiscernible from someone who believes that Aristotle was wise, for instance, must share that same belief. Externalism instead contends that many perfectly ordinary propositional attitudes can be had only in certain sorts of physical, sociolinguistic, or historical context. To have a belief about Aristotle, for instance, a person must have been causally impacted in the right way by Aristotle himself (e.g., by hearing about him, or reading some of his works). An interesting third view, which I call 'weak' internalism, is a mix of what are arguably the most plausible aspects of the two extreme views. On the one hand, the weak internalist rejects the externalist's idea that certain propositional attitudes can be had only in certain sorts of physical, socio-linguistic, or historical context; but on the other hand, she rejects the internalist's claim that microphysical duplicates must be mental duplicates. One of the most vocal opponents of externalism, John Searle, defends a paradigm case of weak internalism. In this paper I explain his view and why it might seem like the ideal compromise: in particular, it captures intuitions underlying both sides of the debate. I then argue, however, that Searle's view is untenable; and my objection shows the untenability of weak internalism in general. Despite the attractiveness of a compromise view, we must choose between internalism and externalism full-stop.