Frege's puzzles

Frege's puzzles are puzzles about the semantics of proper names, although related puzzles also arise in the case of indexicals. Gottlob Frege (1848–1925) introduced the puzzle at the beginning of his article "Über Sinn und Bedeutung" ("On Sense and Reference") in 1892 in one of the most influential articles in analytic philosophy and philosophy of language.