The Truthmakers of Truths About Truths

Josh writes,

I would be interested to see how you respond to the following dilemma (from Peter Geach, "Truth and God," Proceedings of the Aristotelian Society, [1982]: 84).

Say proposition P1 is true because it corresponds to fact F. Does the proposition "Proposition P1 is true" (call it proposition P2) have a truthmaker? It seems that it should. Not only that, it seems that the truthmaker of P2 should be the same as P1 (i.e. F). But it's not obvious how F could make P2 true, since it is not obvious that F shares P2's "propositional" or "language-like structure," as you put it.

You've already said that some propositions do not have truthmakers, so perhaps you could just deny that P2 has a truthmaker. Or perhaps there is a way that F could do the job of truthmaking with respect to P2? Or perhaps P2 could be analyzed in a way that shows it is not really different from P1?

Thanks for your high-quality blogging!

You're very welcome!  Interesting puzzle. It seems obvious that P2 has a truthmaker and that it has the same truthmaker as P1.  Note also that if P1 is contingent, then P2 will also be contingent.  For example, 

Tom is sad

and 

'Tom is sad' is true

are both contingently true and have the same truthmaker, namely,  the contingent fact of

Tom's being sad.

And the same holds for all further iterations such as 

"'Tom is sad' is true" is true.

Iteration of the truth predicate preserves the modal status of the base proposition. The regress here is infinite but benign.  Whatever makes the base proposition true makes true every member of the infinite series of truth predications.

Now the problem you raise is that, while there is a clear isomorphism between 'Tom is sad' and Tom's being sad, there is not the same isomorphism between "'Tom is sad' is true" and Tom's being sad.  The predicate in P2 is the predicate 'true', not the predicate 'sad.'  P1 is about a man and says of him that he is sad; P2 is about a proposition and says of it that it is true.  You are making an assumption, perhaps this:

A. If two or more propositions have the same truthmaker, then they must predicate the same properties of the same subjects.

The truthmaker theorist, however, is not committed to (A).  The singular 'Tom is sad' and the existentially general 'Someone is sad' have the same truthmaker, namely, Tom's being sad, but the two propositions differ in logical form, and the second is not about what the first is about. The singular proposition is about Tom while the general proposition is not.

My point, then, is that the puzzle arises only if we assume (A).  But (A) is no part of truthmaker theory.  Truthmaking is not a 1-1 correspondence.  'Someone is sad' has many different truthmakers, and Tom's being sad makes true many different propositions, indeed, infinitely many. 

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Comments

[Josh]

>>The truthmaker theorist, however, is not committed to (A).<<

Agreed. If I was assuming (A) implicitly, then I repent.

>>Truthmaking is not a 1-1 correspondence.<<

This seems reasonable enough, but isn’t the primary motivation for affirming the existence of facts in the first place that they account for the structural isomorphism that seems to be necessary for (at least one kind of) truthmaking—that is, the kind of truthmaking that obtains when Tom's being sad makes “Tom is sad” true?

We've given examples suggesting (persuasively) that a structural isomorphism between fact and proposition is not necessary for truthmaking. There is no structural isomorphism between Tom's being sad and “'Tom is sad' is true.” We agree. But if structural isomorphism is not necessary for truthmaking, what is?

[BV]

>>But if structural isomorphism is not necessary for truthmaking, what is?<<

What is necessary for truthmaking in general is that there exist something in the world that suffices for the truth of the proposition in question.

This something may or may not be a fact. What is the T-maker of 'Hillary exists'? Hillary. She is also the T-maker of 'Something exists' and 'It is not the case that nothing exists.' But Hillary by herself cannot be the T-maker of 'Hillary is mendacious.' For that we need a fact.

There are two separate questions. First, is there truthmaker role that needs filling? Some will say No. I say Yes. Second, what category or categories of entity are fit to play the role?

[Astute correspondent]

Good suggestion by Josh, and good summary in the main post by Bill.

Plus a good counter objection re 'Tom is sad' and 'someone is sad'.

This is a very difficult one that I need to think about. One of the best posts on this subject so far.

[BV]

Thanks, Astute. I await your explanation of why there is no need for truthmakers.

[Astute]

I emailed you something about three days ago, did you not receive it? The argument is not that there are no truthmakers, but rather, if there were, we would be unable to name them or signify them.

[Josh]

>>There are two separate questions. First, is there truthmaker role that needs filling? Some will say No. I say Yes. Second, what category or categories of entity are fit to play the role?<<

Yes, but I suppose I'm asking a third: namely, what sort of thing is the "truth" that TMs "make"? This question seems to be prior to both of the questions you mention, since before we can know what sort of thing TMs are (if anything at all), we should have a sense of what they're supposed to do. Note: to say what they're supposed to do is to "make propositions true" is question-begging, since precisely what is at issue is the nature of this truth. Quid sit veritas?

Presumably, on TM theory, we know that what TMs are supposed to "make" is some kind of relation between a mental/linguistic proposition and a real-world entity (which might not be a fact, as you point out). The difficulty as I see it is this: what seems to be the best candidate for this truth-relation--namely, a structural isomorphism between a proposition and a TM--cannot do the job.

Perhaps this is simply not the question you are asking, but it does seem to be important.

[BV]

Astute,

I did not receive the e-mail in question. Please re-send.

[BV]

Josh,

We take as a datum that some judgments, beliefs, sentences, etc. are true and that some are not. We don't start with a theory, but with a given. We then go on to ask whether the truth of (some of) these representations requires the existence of extra-representational entities.

I don't know what you are driving at.

[Josh]

What I'm driving at is simply the question of the meaning of the word "true" in the phrase "true proposition." In order to know whether we need extra-representational entities in order to have truth, don't we need to have some idea of what the word "true" means? Here are some possibilities I could imagine off the top of my head:

1. The predicate "true" sometimes denotes some sort of correspondence relation between a linguistic, truth-bearing proposition and a non-linguistic, truth-making entity; therefore in order to have (this kind of) truth, we need some sort of non-linguistic truth-maker.

2. The predicate "true" denotes some sort of coherence relation between a proposition and all other true propositions; therefore in order to have truth, there is no need for some sort of non-linguistic truth-maker.

3. The predicate "true" denotes the usefulness of a given belief for achieving some sort of desirable end; therefore in order to have truth, there is no need for some sort of non-linguistic truth-maker.

In each case, the correct answer to the TM question is determined by the prior question of what truth is. The vaguer the concept of truth, the worse off we are when it comes to this TM business. Yes?