Gottlob Frege developed a theory of propositions that assert the elements of propositions are concepts, or modes of presentation. (I'm not sure 'concept' really captures 'mode of presentation', but no worries about that for now.) Steven Schiffer offers the following objection to the Fregean theory of proposition, which he attributes to Adam Pautz:
(1) If the Fregean theory is true, then (α) 'Fido' occurs in 'Ralph believes that Fido is a dog' as a singular term whose referent is a concept of Fido.
2) If (α), then the following inference is valid:
________Ralph believes that Fido is a dog
________∴∃x( x is a concept and Ralph believes that x is a dog).
3) But the inference isn't valid; given the truth of the premise, the conclusion is also true only in the unlikely event that Ralph mistakes a concept for a dog.
4) ∴The Fregean theory is not true.
(Source: Shiffer (2003) The Things We Mean, Oxford: Oxford University Press, p. 27.)
But is the problem here an incomplete shift into the realm of concept talk? Yes, for Fregeans, all propositions are about concepts. But sometimes the concepts are being used translucently, as if we are simply seeing through them to the 'real world,' while at other times we are focusing on them as concepts. 'Fido is a dog' is an instance of the first type of usage. What Pautz seems to have done here, to me, is shift part of the sentence to the second type of usage. And, of course, where we are focusing on the conceptual aspect of the first term, but the real world aspect of the second, the result looks quite odd. If we complete the transition, then what I think we get is something like:
∃x( x is a concept [named by 'Fido'] and Ralph believes that x is a member of a class of concepts [named by 'dog'])
This new conclusion to our inference makes perfect sense, as far as I can see.
Any comments? Did I go wrong somewhere?
UPDATE: Did Frege's first name derive from his prowess at tennis? ('Man, Frege done got lob!')