De Se

De se is Latin for "of oneself" and, in philosophy, it is a phrase used to mark off what some believe to be a category of ascription distinct from "de dicto and de re".

David Lewis's article (below) gave birth to the topic, and his expression of it draws heavily on his distinctive theory of possible worlds.

A sentence such as: "Peter thinks that he is pale" where the pronoun "he" is meant to refer to Peter is ambiguous in a way not captured by the de dicto / de re distinction. Such a sentence could report that Peter has the following thought: "I am pale". Or Peter could have the following thought: "he is pale", where it so happens that the pronoun "he" refers to Peter, but Peter is unaware of it. The first meaning expresses a belief de se, while the second does not.

This notion is now thoroughly discussed in the philosophical literature, but especially in the theoretical linguistic literature, the latter because some linguistic phenomena clearly are sensitive to this notion.

This can be illustrated simply. Imagine the following scenario:

Peter, who is running for office, is drunk. He is watching an interview of a candidate on TV, not realizing that this candidate is himself. Liking what he hears, he says: "I hope this candidate gets elected." Having witnessed this, one can truthfully report Peter's hopes by uttering: "Peter hopes that he will get elected", where "he" refers to Peter, since "this candidate" indeed refers to Peter. However, one could not report Peter's hopes by saying: "Peter hopes to get elected". This last sentence is only appropriate if Peter had a de se hope, that is a hope in the first person as if he had said "I hope I get elected", which is not the case here.