de dicto of what is said (or of the proposition), as opposed to de re, of the thing. Many philosophers believe the following ambiguous, depending on whether they are interpreted de dicto or de re: (1) It is possible that the number of U.S. states is even. (2) Galileo believes that the earth moves.
Assume for illustrative purposes that there are propositions and properties. If (1) is interpreted as de dicto, it asserts that the proposition that the number of U.S. states is even is a possible truth – something true, since there are in fact fifty states. If (1) is interpreted as de re, it asserts that the actual number of states (fifty) has the property of being possibly even – something essentialism takes to be true. Similarly for (2); it may mean that Galileo’s belief has a certain content – that the earth moves – or that Galileo believes, of the earth, that it moves.
More recently, largely due to Castañeda and John Perry, many philosophers have come to believe in de se (‘of oneself’) ascriptions, distinct from de dicto and de re. Suppose, while drinking with others, I notice that someone is spilling beer. Later I come to realize that it is I. I believed at the outset that someone was spilling beer, but didn’t believe that I was. Once I did, I straightened my glass. The distinction between de se and de dicto attributions is supposed to be supported by the fact that while de dicto propositions must be either true or false, there is no true proposition embeddable within ‘I believe tha. . .’ that correctly ascribes to me the belief that I myself am spilling beer. The sentence ‘I am spilling beer’ will not do, because it employs an ‘essential’ indexical, ‘I’. Were I, e.g., to designate myself other than by using ‘I’ in attributing the relevant belief to myself, there would be no explanation of my straightening my glass. Even if I believed de re that LePore is spilling beer, this still does not account for why I lift my glass. For I might not know I am LePore. On the basis of such data, some philosophers infer that de se attributions are irreducible to de re or de dicto attributions. See also KNOWLEDGE DE RE, TOKEN- REFLEXIV. E.L.