On the prosentential theory of truth, a prosentence,
e.g., ‘that’s true’, is substituted for the truth predicate, ‘… is true’, a
pro-form forming operator, such that the putative inter-linguistic word-world
relation may be replaced with a purely expressive intra-linguistic word-word
relation. Since the semantic content of anaphoric antecedents and prosentences
presume a relation between a proposition and the world, these truth conditions
turn out to be genuine language-independent properties. Proforms are a category of grammatical devices of which pronouns and proverbs are most familiar. Pronouns function grammatically as nouns and may be substituted for previously mentioned nouns. Proverbs function grammatically as verbs and stand in form previously mentioned actions. Since so many grammatical forms have proforms, it should not be surprising for langauge to have a proform for sentences: prosentences. Prosentences have the grammatical structure of a sentence, and stand in for previous sentences. Jill said, "The taxes the state charged me is too high." "That's true," said the tax assessor, "but you ought to pay it now and dispute it by legal means later." Just as with pronouns and proverbs, the prosentence, "That's true," points back to the previous sentence. This special prosentence inherits content in a similar way that a pronoun such as "he" or "she" relates to and inherits its content from its antecedent. "That's true" is an anaphor for some antecedent. That is all, on the prosentential account, that one needs to know to understand truth.