In this paper, I argue against an influential view of Frege's writings on indexical and other context-sensitive expressions, and in favour of an alternative. The centrepiece of the influential view, due to (among others) Evans and McDowell, is that according to Frege, context-sensitiveword-meaning plus context combine to express senses which are essentially first person, essentially present tense and so on, depending on the context-sensitive expression in question. Frege's treatment of indexicals thus fits smoothly with his Intuitive Criterion of difference of sense. On my view, by contrast, Frege stuck by the view which he held in his unpublished 1897 ‘Logic’, namely that the senses expressed by the combination of context-sensitive word-meaning and context could just as well be expressed by means of non-context-sensitive expressions: being first person, present tense and so on are properties, in Frege's view, only of language, not of thought. Given the irreducibility of indexicals – a phenomenon noticed by Castañeda, Perry and others – Frege's treatment of indexicals thus turns out to be inconsistent with the Intuitive Criterion. I argue that Frege was not aware of the inconsistency because he was not aware of the irreducibility of indexicals. This oversight was possible because the source of Frege's interest in indexicals, as inother context-sensitive expressions, differed from that of contemporary theorists. Whereas contemporary theorists are most often interested in indexicals (and in Frege's treatment of them) because they are interested in the indexical versions of Frege's Puzzle and their relation to psychological explanation, Frege himself was interested in them because they pose a prima facie threat to his general conception of thoughts. The only indexical expression Frege's view of which the above account does not cover is ‘I’ insofar as it is associated with ‘special and primitive’ senses, but Frege did not introduce such senses with a view to explaining theirreducibility of ‘I’ his real reason for introducing them remains obscure.