Externalism, Self-Knowledge, and the Prevalence of Slow Switching
In an influential article, Paul Boghossian [1] has argued that externalism about mental content and a priori self-knowledge are incompatible doctrines. Commandeering the slow switching thought experiment introduced by Burge [3] (where an agent unknowingly switches between Earth and Twin Earth), Boghossian argues that it appears possible for an agent S to know his thoughts at time t, forget nothing, yet at some time later than t (perhaps having been informed that switches were taking place) be unable to say what the contents of his thoughts were at t. As Boghossian argues,