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.”. (shrink)

Two periods in the history of logic and philosophy are characterized notably by vivid interest in self-referential paradoxical sentences in general, and Liar sentences in particular: the later medieval period (roughly from the 12th to the 15th century) and the last 100 years. In this paper, I undertake a comparative taxonomy of these two traditions. I outline and discuss eight main approaches to Liar sentences in the medieval tradition, and compare them to the most influential modern approaches to such sentences. (...) I also emphasize the aspects of each tradition that find no counterpart in the other one. It is expected that such a comparison may point in new directions for future research on the paradoxes; indeed, the present analysis allows me to draw a few conclusions about the general nature of Liar sentences, and to identify aspects that would require further investigation. (shrink)