De dicto and de re

De dicto and de re are two phrases used to mark a distinction in intentional statements, associated with the intentional operators in many such statements. The distinction is used regularly in metaphysics and in philosophy of language.

The literal translation of the phrase "de dicto" is "about what is said", whereas de re translates as "about the thing". The original meaning of the Latin locutions may help to elucidate the living meaning of the phrases, in the distinctions they mark. The distinction can be understood by examples of intentional contexts of which three are considered here: a context of thought, a context of desire, and a context of modality.

There are two possible interpretations of the sentence “Peter believes someone is out to get him”. On one interpretation, ‘someone’ is unspecific and Peter suffers a general paranoia; he believes that it is true that a person is out to get him, but does not necessarily have any beliefs about who this person may be. What Peter believes is that the predicate ‘is out to get Peter’ is satisfied. This is the de dicto interpretation.

On the de re interpretation, ‘someone’ is specific, picking out some particular individual. There is some person Peter has in mind, and Peter believes that person is out to get him.

In the context of thought, the distinction helps us explain how people can hold seemingly self-contradictory beliefs. Say Lois Lane believes Clark Kent is weaker than Superman. Since Clark Kent is Superman, taken de re, Lois’s belief is untenable; the names ‘Clark Kent’ and ‘Superman’ pick out an individual in the world, and a person (or super-person) cannot be stronger than himself. Understood de dicto, however, this may be a perfectly reasonable belief, since Lois is not aware that Clark and Superman are one and the same.

Consider the sentence "Jana wants to marry the tallest man in Fulsom County". It could be read either de dicto or de re; the meanings would be different. One interpretation is that Jana wants to marry the tallest man in Fulsom County, whoever he might be. On this interpretation, what the statement tells us is that Jana has a certain unspecific desire; what she desires is that a certain situation should obtain, namely, Jana's marrying the tallest man in Fulsom County. The desire is directed at that situation, regardless of how it is to be achieved. The other interpretation is that Jana wants to marry a certain man, who in fact happens to be the tallest man in Fulsom County. Her desire is for that man, and she desires herself to marry him. Again, the first interpretation, "Jana desires that she marry the tallest man in Fulsom County", is the de dicto interpretation. The second interpretation, "Of the tallest man in Fulsom County, Jana desires that she marry him", is the de re interpretation.

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