Full Idea
Instances of the truthmaker principle are equivalent to biconditionals not about truth but about the existential grounding of all manner of other things; the flying pigs, or what-have-you.
Gist of Idea
Truthmakers are about existential grounding, not about truth
Source
David Lewis (Forget the 'correspondence theory of truth' [2001])
Book Reference
-: 'Analysis' [-], p.279
A Reaction
The question then is what the difference is between 'existential grounding' and 'truth'. There wouldn't seem to be any difference at all if the proposition in question was a simple existential claim.