In this Chapter, in several places I discuss the idea that the essential indexical can be reduced to the notion of "I", with reference to various authors. I then move on to the discussion of Immunity to Error through misidentification to show what the consequences of the pragmatics of "de se" are for this issue. I consider an objection that "I" need not be first-personal and I reply to it armed with contextualism. The discussion is mainly philosophical, but it has linguistic consequences, as my main idea is that IEM is to be explained at least in part linguistically.