Wittgenstein on Psychological Certainty

As is well-known, Wittgenstein pointed out an asymmetry between first- and third-person psychological statements: the latter, unlike the former, involve observation or a claim to knowledge, and are therefore constitutionally open to uncertainty. In this paper, I challenge this asymmetry by challenging the constitutional uncertainty of third-person psychological sentences, and argue that Wittgenstein ultimately also did. There are cases where third-person psychological ascriptions are not susceptible of error.