How do I know that I am thinking about water? Externalism, self-knowledge, and the fallacy of incompatibilism
Externalism is a theory of mental content the central thesis of which is that the identities of some mental contents are at least partially determined by relations with the external world; its antithesis is internalism, which holds that all mental contents are completely determined internally.
Prima facie, there is an incompatibility between externalism and the ability of a thinker to know his thoughts, a.k.a. self-knowledge. Externalism predicts that certain thoughts (wide thoughts) are, in part, determined by external relations; the problem is that it does not appear that a thinker can know his own wide thoughts without investigating these external relations, thereby threatening the strongly intuitive idea that thinkers know the contents of their thoughts solely via introspection.
In this paper, this seeming incompatibility, and the objections that employ it, is investigated. Despite its intuitive pull, this incompatibility is false and its falsity is demonstrated via a dilemma.