For Perry and many authors, de se thoughts are a species of de re thought. In this paper, I argue that de se thoughts come in two varieties: explicit and implicit. While explicit de se thoughts can be construed as a variety of de re thought, implicit de se thoughts cannot: their content is thetic, while the content of de re thoughts is categoric. The notion of an implicit de se thought is claimed to play a central role in accounting for the phenomenon of immunity to error through misidentification.

Lewis has attempted to unify de re and de se in the opposite direction: by reducing de re to de se. This, however, works only if we internalize the acquaintance relations. I criticize Lewis's internalization strategy on the grounds that it rests on Egocentrism (the view that every occurrent thought is ultimately about the thinker at the time of thinking). In the conclusion, I suggest another way of unifying de re and de se, by extending the implicit/explicit distinction to de re thoughts themselves.