It is accepted that first-person thoughts are immune to error through misidentification.I argue that there is also immunity to error through misascription, failure to recognise which has resulted in mistaken claims that first-person thoughts involving the self-ascription of bodily states are, at best, circumstantially immune to error through misidentification relative to ‘I’ and, at worst, subject to error. Central to my thesis is that, first, ‘I’ is immune to error through misidentification absolutely, and that if there is any problem with first-person thoughts this cannot be with the self-identification component, but only with the self-ascriptive component.Secondly, the ‘know who’, or ‘know what’, or ‘know which’ requirement is appropriately relevant to considerations of different self-ascriptive properties, and thus its inapproriateness in self-identification does not entail that ‘I’ may fail to refer and identify.