Burge follows Descartes in claiming that the category of conceptually self-verifying judgments includes (but is not restricted to) judgments that give rise to sincere assertions of sentences of the form, 'I am thinking that p'. In this paper I argue that Burge’s Cartesian insight is hard to reconcile with Fregean accounts of the content of thought. Burge's intuitively compelling claim that cogito judgments are conceptually self-verifying poses a real challenge to neo-Fregean theories of content.