Full Idea
If the subject-matter of S is how it is true, we get three unfortunate results: S has truth-value in worlds where its subject-matter draws a blank; learning what S is about tells you its truth-value; negating S changes what it's about.
Gist of Idea
Truth-conditions as subject-matter has problems of relevance, short cut, and reversal
Source
Stephen Yablo (Aboutness [2014], 02.8)
Book Reference
Yablo,Stephen: 'Aboutness' [Princeton 2014], p.43
A Reaction
Together these make fairly devastating objections to the truth-conditions (in possible worlds) theory of meaning. The first-objection concerns when S is false