Comments Elsewhere

An exegetical note off to the side:

Protagoras: Frege seems to have thought sentences with non-referring expressions are meaningless, ….

This is a common misunderstanding of Frege’s view, one that I suspect comes about from people reading Russell and Wittgenstein’s thoughts about propositional meaning and truth-valuability back into Frege, who did not share their conclusions. Wittgenstein and Russell held that any significant proposition has a truth value, but what Frege explicitly states in “Ãœber Sinn und Bedeutung” is statements with empty proper names express a thought but have no truth-value. Since Frege’s claim is that the sense of a statement is the thought expressed by it, and the referent of a statement is its truth-value, this means that he regards them as having a sense but no reference, just as (he thinks) the empty designator in them has a sense but no reference. Here’s the relevant passage:

“The thought, accordingly, cannot be the Bedeutung of the sentence, but must rather be considered as its sense. What is the position now with regard to the Bedeutung? Have we a right even to inquire about it? Is it possible that a sentence as a whole has only a sense, but no Bedeutung? At any rate, one might expect that such sentences occur, just as there are parts of sentences having sense but no Bedeutung. And sentences which contain proper names without Bedeutung will be of this kind. The sentence ‘Odysseus was set ashore at Ithaca while sound asleep’ obviously has a sense. But since it is doubtful whether the name ‘Odysseus’, occurring therein, has a Bedeutung, it is also doubtful whether the whole sentence does. Yet it is certain, nevertheless, that anyone who seriously took the sentence to be true or false would ascribe to the name ‘Odysseus’ a Bedeutung, not merely a sense; for it is of the Bedeutung of the name that the predicate is affirmed or denied. Whoever does not admit the name has a Bedeutung can neither apply no withhold the predicate. But in that case it would be superfluous to advance to the Bedeutung of the name; one could be satisfied with the sense, if one wanted to go no further than the thought. If it were a question only of the sense of the sentence, the thought, it would be needless to bother with the Bedeutung of a part of the sentence; only the sense, not the Bedeutung, of the part is relevant to the sense of the whole sentence. The thought remains the same whether ‘Odysseus’ has a Bedeutung or not.” (32-33)

Hope this helps.