An American philosopher and logician, David Benjamin Kaplan was born in Los Angeles in 1933 and has spent his career mainly at the University of California, Los Angeles: first as an undergraduate student (AB in Philosophy, 1956; AB in Mathematics, 1957); then as graduate student (PhD in Philosophy, 1964), where he wrote the last dissertation Rudolf Carnap supervised; later as a faculty member, where he became Hans Reichenbach Professor of Scientific Philosophy in 1994.

Kaplan is best known for his work in formal semantics, particularly on the semantics of demonstratives and other indexicals: expressions such as this, that purple Mercedes convertible, I, you, here, now, and actually. In Demonstratives, Kaplan developed a theoretical framework in which sentences express propositions relative to contexts. The content of an expression (relative to a context C) is what it contributes to the propositions expressed (relative to C) by sentences that contain it. The...