John Perry

Philosophers and logicians use the term “indexical” for words such as “I”, “you” and “tomorrow”. Demonstratives such as “this” and “that” and demonstratives phrases such as “this man” and “that computer” are usually reckoned as a subcategory of indexicals. (Following [Kaplan, 1989a].) The “context-dependence” of indexicals is often taken as a defining feature: what an indexical designates shifts from context to context. But there are many kinds of shiftiness, with corresponding conceptions of context. Until we clarify what we mean by “context”, this defining feature remains unclear. In sections 1–3, which are largely drawn from [Perry, forthcoming(a)], I try to clarify the sense in which indexicals are context-dependent and make some distinctions among the ways indexicals depend on context. In sections 3–6, I contrast indexicality with another phenomenon that I call “unarticulated constituents.”.

The topic of this essay is “the slingshot,” a short argument that purports to show that sentences1 designate (stand for, refer to) truth values. Versions of this argument have been used by Frege 2, Church 3, Quine4 and Davidson5; thus it is historically important, even if it immediately strikes one as fishy. The argument turns on two principles, which I call substitution and redistribution. In “Semantic Innocence and Uncompromising Situations,”6 Jon Barwise and I rejected both principles, as part of our attempt..