Rudolf Lingens

Severe amnesiac Rudolf Lingens has become famous for being lost in Stanford Library, aisle 5, floor 6 of Main Library Stanford. In fact, he's lost there right now.

De se attitudes

Lingens was invented by philosopher John Perry to star in a thought-experiment meant to show the importance of indexical, or de se belief. His first appearance in print was in Perry's 1977 article 'Frege on Demonstratives'. The crux is that Lingens, after reading encyclopedic entries like this very one, might know exactly where Lingens is without knowing where he himself is, since he does not know that he is Lingens. Conclusion: Belief one has about oneself can be indirect (e.g. having read that someone called Lingens is in the Stanford Library) or direct (knowing:' I am Lingens, so I am located in the Stanford Library.'). This division, sometimes called the de re vs. de se distinction, has ramifications for the theory of propositional attitudes and the semantics of belief reports, concerning fields like linguistics (esp. the subfield of semantics), philosophy of mind and philosophy of language.

References

(standard philosophical references for de se that discuss Lingens' predicament)

• John Perry (1977) Frege on demonstratives Philosophical Review 86 pp.474–97
• David Lewis (1979) Attitudes de dicto and de se Philosophical Review 88 pp.513–43
• David Kaplan (1989) Demonstratives. In Themes from Kaplan, ed. by Joseph Almog, John Perry & Howard Wettstein. New York: Oxford University Press. pp. 481–614.