This paper relates Kant'saccount of pure apperception to the agential approach to self-knowledge. It argues that his famous claim ‘The I think must be able to accompany all of my representations’ (B131) does not concern the possibility of self-ascribing beliefs. Kant does advance this claim in the service of identifying an a priori warrant we have as psychological persons, that is, subjects of acts of thinking that are imputable to us. But this warrant is not one to self-knowledge that we have as critical reasoners. It is, rather, an a priori warrant we have, as thinkers, to prescribe to given representations their conformity to principles of thinking inherent in our capacity of understanding itself.