De re/de dicto

‘De re’ and ‘de dicto’ have been used to label a host of different, albeit interrelated, distinctions. ‘De dicto’ means ‘of, or concerning, a dictum’, that is, something having representative content, such as a sentence, statement or proposition. ‘De re’ means ‘of, or concerning, a thing’. For example, a de dicto belief is a belief that a bearer of representative content is true, while a de re belief is a belief concerning some thing, that it has a particular characteristic.

Consider the following example:

This statement is ambiguous. Construed de dicto, it is true in the following circumstance. John has never had any contact with his next-door neighbour. Nevertheless, John believes that his next-door neighbour is bound to be a Buddhist. Construed in this de dicto fashion, the statement does not attribute to John a belief that is distinctively about a particular individual. In contrast, construed de re, it does attribute to John a belief that is about a particular individual. For example, construed de re, the statement is true in the following circumstance. John encounters his next-door neighbour, Fred, at a party without realizing that Fred is his next-door neighbour. On the basis of his conversation with Fred, John forms a belief about the individual who is in fact his next-door neighbour to the effect that he is a Buddhist.