Maverick Philosopher

Footnotes to Plato from the foothills of the Superstition Mountains

Presentism and Truthmakers: A Reply to David Brightly

I first want to apologize to David Brightly for not paying more attention to his ongoing gentlemanly critique of my ideas at his weblog, tillyandlola: Comments on the Maverick.    Although our minds work in very different ways, this is scant excuse for my not having engaged his incisive and well-intentioned critique more fully.  I shall make amends in this Lenten season and beyond. On 28 April 2019, he posted the following:

Presentism and Truthmakers

 
Bill runs through the truthmaker objection to presentism:  truths about the past are truths now and hence need present truthmakers yet under presentism there don't seem to be any.  Let's consider a variant of Bill's example: 

S. Kennedy commanded PT109.  

That's true.  But what in the present grounds this truth? On the face of it, that's a rather weird question.  Why should we expect there to be something about the world now that grounds a truth about the past? But Bill has a point I think: we say that S is true, now.  Bill rightly dismisses Ed Feser's half-hearted attempt to reconcile presentism and truthmakerism.  So what should we say about this puzzle?

Consider this sentence:

T.  Kennedy commands PT109.

In 1943 T was true and we may suppose that in 1943 the world was in some way that made it true.  But now in 2019 that way has long since ceased to be and T is no longer true.  How then do we express the way of 1943 from the vantage point of 2019?  We can't just use T as that is false.  Instead, the rules of English, unchanging over the intervening period, tell us to use S, a modification in tense of T.  The past way, once expressed by T is now expressed by S.  S is not a brute truth.  It's a rule-governed transformation of a made truth.  

 
………………………..
 
Brightly appreciates that it won't do to say that (S) is just true.  As a contingent truth, (S) needs something external to it to explain its being true.  It needs a truthmaker. David also appreciates that, while the past-tensed (S) is true at present, on presentism  nothing that exists at present  could serve as the truthmaker of (S). Brightly's theory seems to be that because the past-tensed (S) is a rule-governed transformation of the present-tensed (T), and because (T) was a "made truth," i.e, was a truth having a truthmaker, (S) has a truthmaker too, namely the truthmaker of  (T).
 
But note that (T) WAS made true in 1943 by something that existed then, but does not exist now. So it is difficult to see how the truthmaker of (T) that DID exist, but does not now exist, can serve as the truthmaker of S.  (S) is true at present, and such a truth, if it has a truthmaker, has an existent truthmaker, a truth maker that on presentism presently exists. Equivalently, although (T) WAS true in 1943, it is false now.  Being false now, it has no truthmaker now. So if the truthmaker of (S) now is the truthmaker (T) had then, then (S) has no truthmaker now.  
 
Brightly might simply be denying that past-tensed contingent truths such as (S) need truthmakers. But if present-tensed contingent truths need them — and they obviously do — then it it is difficult to see how the mere passage of time can absolve them of this need when these present-tensed truths become past-tensed truths by that "rule-governed transformation" that David spoke about.  For example, 'I am blogging' is now true, but in an hour it will be false. An hour from now 'I was blogging' will be true.  Now abstract from tense and indexicality. The result is BV blogs. The bolded expression picks out the tenseless propositional content that is common to the present-tensed 'BV is blogging' (or 'BV blogs')  and the past-tensed 'BV was blogging' (or 'BV blogged.')
 
It is the contingency of that propositional content, and its reference beyond itself, that requires that there be a truthmaker for said content.  The tense of the content is irrelevant to the requirement.  So if present-tensed truths need truthmakers, then so do past-tensed truths.  The mere passage of time cannot abrogate the requirement.
 
If so, then the truthmaker objection to presentism is up and running. For on presentism, the present alone exists. But if so, then there are no past-tensed contingent truths: there is nothing in reality to ground their truth. The upshot would appear to be a denial of the reality of the past.  

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Bill Vallicella

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6 responses to “Presentism and Truthmakers: A Reply to David Brightly”

  1. EGP Avatar
    EGP

    Bill, my thoughts are half-baked, so bear with me. I’m wondering if it must be the case that every truthbearer of a contingently true proposition must be a concrete entity. What if, for every concrete state of affairs, there is a corresponding abstract entity – let’s call it a “fact” – and it is this fact that serves as the truthbearer of the proposition.

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  2. BV Avatar
    BV

    Sorry, but I have to stop you right there. Propositions are one species of truthbearer. So it makes no sense to speak of the truthbearer of a proposition. You appear also to be confusing truth bearers with truthmakers.

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  3. EGP Avatar
    EGP

    Apologies, that was indeed a typographical error. My question, corrected: I’m wondering if it must be the case that every truthmaker of a contingently true proposition must be a concrete entity. What if, for every concrete state of affairs, there is a corresponding abstract entity – let’s call it a “fact” – and it is this fact that serves as the truthmaker of the proposition.
    How would you evaluate my suggested argument?
    Eternal Truthmakers for Temporal Truthbearers
    1) Suppose that simultaneously to me writing this, Barack Obama is sitting in his living room sofa.
    2) Therefore, the truthbearer expressed by the English sentence, ‘Barack Obama is sitting in his living room sofa’ is true. Call this truthbearer B (set aside for the time being all questions of the nature of B, whether it is a Russellian proposition, a Fregean Thought, etc.).
    3) Therefore, there exists a truthmaker in virtue of which B is true.
    4) The truthmaker cannot consist of either Barack Obama, Barack Obama’s living room sofa, or even both Barack Obama and his living room sofa together.
    5) Rather, the truthmaker is the *fact* that Barack Obama is sitting in his living room sofa. Call this fact F.
    6) Facts are abstract objects, not concrete objects.
    7) Abstract objects do not exist temporally, but eternally; that is, they do not exist in time, but outside of time.
    8) Therefore, F does not exist temporally, but eternally; it does not exist in time, but outside of time. To restate this explicitly: The fact F which serves as the truthmaker for the truthbearer B expressed by the English sentence, ‘Barack Obama is [presently] sitting in his living room sofa’ exists eternally, even as Barack Obama is sitting in his living room sofa *now*.
    9) Suppose that as I now write Argument Line 9, Barack Obama has stood up, and has walked to his kitchen.
    10) Therefore, the truthbearer B expressed by the English sentence, ‘Barack Obama is sitting in his living room sofa’ is now false.
    11) However, the truthbearer expressed by the English sentence, ‘Barack Obama *was* sitting in his living room sofa’ is true. Call this truthbearer B’.
    12)The truthmaker in virtue of which B’ is true is the fact F. In other words, the truthmaker of B when B was true is numerically identical with the truthmaker of B’.
    13) Therefore, the truthmaker of B’ does not exist temporally, but eternally.
    14) According to the thesis of Presentism, only present objects and events, along with eternal objects, exist.
    15) B’ concerns past objects and events.
    16) Although B’ concerns past objects and events, the truthmaker of B’ consists of neither past objects and events nor present objects and events, but the eternally existing fact F.
    17) Therefore, the truth of truthbearers that are concerned with past objects and events is consistent with the thesis of Presentism.
    Q.E.D.

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  4. David Brightly Avatar
    David Brightly

    Good Morning, Bill, and thank you for those words of encouragement. I wrote that piece thinking that a presentist ought to be able to do better than say that contingent past tensed truths were brute, as here. Some kind of grounding needs to be offered. But also that truthmaking theory seems to leave out an important linguistic element. Namely that part of what makes ‘Tom is red’ true when Tom is red is that ‘Tom’ is the ‘right’ way to refer to your tomato friend, that ‘red’ is the right way to refer to his colour, and that ‘is’ is the right way of tensing the sentence.
    You say that it is difficult to see how the truthmaker of (T) that DID exist, but does not now exist, can serve as the truthmaker of S. It seems the obvious candidate to my naive understanding of truthmaker theory. What does theory demand that I’m missing?

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  5. BV Avatar
    BV

    Good morning, David. Thanks for the response.
    T: Kennedy commands PT 109.
    S: Kennedy commanded PT 109.
    We agree that (T) had a truthmaker in ’43, but does not have one now, and that the absence of a truthmaker now is what accounts for (T)’s being false now.
    We also agree that the past-tensed (S) needs a truthmaker. We disagree over whether the truthmaker of (T) is the truthmaker of (S). You say it is; I say it can’t be.
    Is that the point in dispute? I’d say it is.
    I assume that a T-maker cannot do its job unless it exists. If x makes-true y, then (i) y is true and (ii) x exists. Is that not self-evident? Now on presentism, whatever exists, exists at present. This implies that wholly past items such as Kennedy and his commanding of the PT 109 do not exist, that they are nothing. But then it follows that the T-maker of (T) cannot be the T-maker of (S). This is because the T-maker of (T) does not exist.
    Please explain why you do not accept this reasoning.

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  6. David Brightly Avatar
    David Brightly

    I agree that’s the point in dispute. What I’m having trouble accepting is the characterisation of truth-making in the form x makes-true y where x is presumably a state of affairs and y a sentence. This may be satisfactory when everything is in the present but I think my Kennedy example shows it to be too coarse-grained when y is past-tensed. We need something more akin to x@t1 makes-true y@t2 understood as soa x holding at time t1 makes-true sentence y uttered at time t2. This allows interesting distinctions even with present-tensed y. For example, BV’s blogging at 3pm does not makes-true “BV blogs” said at 2pm even though “BV blogs” may be true at 2pm.

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