The de re/de dicto distinction matters for propositions involving objects and their properties. "John wants to marry a millionaire" (de dicto: he wants someone with money) differs from "John wants to marry that millionaire" (de re: about a particular individual). Understanding how attitudes relate to referential content is crucial for philosophy of mind and language, especially given externalism about content.
Use Quine's famous example: Ralph believes de dicto that a spy is a patriot, but de re (of the actual spy he sees), Ralph believes him to be a patriot. Practice translating English sentences into logical form, noting how quantifier scope and operator scope interact. Study Kaplan's semantics for de re attributions and how they depend on direct reference to objects.
From your study of intentionality and aboutness, you know that mental states and linguistic expressions can be about things — they have content that points toward objects or states of affairs in the world. The de re / de dicto distinction is a refinement of this: it asks *how* an attitude or statement is about its object, and specifically whether the object is picked out as a definite individual or merely as whatever satisfies a description.
Start with a concrete example. Suppose John wants to marry a millionaire, but he has no particular person in mind — he just wants whoever happens to have that much money. This is a de dicto attitude: John's desire is about the description "a millionaire," *dictum* being Latin for "what is said." Now suppose John is secretly in love with his neighbor Sarah, who (unknown to him) is a millionaire. John wants to marry *Sarah*. This is a de re attitude: his desire is about a specific *res* — a particular thing in the world — regardless of how he or anyone else describes it. De re attitudes are object-directed in a direct, referential way; de dicto attitudes are description-directed. The same English sentence — "John wants to marry a millionaire" — is often genuinely ambiguous between these two readings.
Your study of first-order logic syntax helps here. The de dicto reading of "John wants a millionaire wife" places the existential quantifier *inside* the scope of the attitude operator: John wants [there to exist an x such that x is a millionaire and he is married to x]. The de re reading places the quantifier *outside*: there exists an x such that x is a millionaire and John wants [to be married to x]. The difference in quantifier scope is the formal marker of the distinction. Quine's famous spy example illustrates the stakes: Ralph believes de dicto that someone is a spy (there is a spy somewhere). He believes de re of Ortcutt — a particular person he has seen — that Ortcutt is not a spy. But Ortcutt is in fact the spy. Does Ralph believe of the spy that he is not a spy? The de re reading says yes, because the belief is about Ortcutt the individual, not about Ortcutt under any description.
Why does this matter for philosophy of mind and language? Because content externalism — the view that the content of your thoughts is partly determined by what is in your environment, not just what is in your head — applies differently to de re and de dicto attitudes. A de re belief about water is a belief about H₂O whether or not the believer knows the chemical formula. A de dicto belief "I believe that water is wet" might have a different content in a Twin Earth scenario where the watery stuff has a different chemical composition. De re attitudes seem especially vulnerable to Putnam-style externalist arguments, because their content is anchored to the actual object of the belief, not the believer's internal description of it.
The deeper issue is what kind of cognitive relation is required for a genuinely de re attitude. It is tempting to say: all you need is causal contact with the object. But the right kind of cognitive grip seems to matter. You are causally connected to distant stars, but most philosophers would say you cannot have de re beliefs about a particular star unless you have some epistemic or referential access to it — through perception, testimony, proper names, or tracking. This is why Kaplan's semantics for de re attributions appeal to notions like acquaintance: a de re belief requires that the believer stand in the right kind of direct cognitive relation to the object, not merely that the object causally influenced them at some point. Working out precisely what that relation is connects this topic directly to your upcoming study of semantic content externalism.
Topics in reflective domains aren't scored by quiz answers. Read, reflect, and mark when you've thought it through.