Rudolph Lingens is a fictional character often used by contemporary analytic philosophers as a placeholder name in a hypothetical scenario which illustrates some feature of the indexicality of natural language.
Lingens first appeared in Frege's influential essay 'Thought' ('Der Gedanke', published in Beiträge zur Philosophie des deutschen Idealismus I (1918–19), pp. 58–77).
Frege's discussion is concerned with how proper names and indexicals like 'I' function and how they are connected with the sense (or mode of presentation) that, on his account, each speaker who uses them associates with them.
Rudolph Lingens makes a number of appearances in the subsequent literature on Frege and on indexicals.
[4] In his paper, Stalnaker suggests that Lingens is the cousin of Bernard J. Ortcutt, a character originally created by W.V.