Abstract
Many philosophers believe that truth is grounded: True propositions depend for their truth on the world. Some philosophers believe that truth’s grounding has implications for our ontology of time. If truth is grounded, then truth supervenes on being. But if truth supervenes on being, then presentism is false since, on presentism, e.g., that there were dinosaurs fails to supervene on the whole of being plus the instantiation pattern of properties and relations. Call this the grounding argument against presentism. Many presentists claim that the grounding argument fails because, despite appearances, supervenience is compatible with presentism. In this paper, I claim that the grounding argument fails because, despite appearances, truth’s grounding gives the presentist no compelling reason to adopt the sort of supervenience principle at work in the grounding argument. I begin by giving two precisifications of the grounding principle: truthmaking and supervenience. In Sect. 2, I give the grounding argument against presentism. In Sect. 3, I argue that we should distinguish between eternalist and presentist notions of grounding; once this distinction is in hand, the grounding argument is undercut. In Sect. 4, I show how the presentist’s notion of grounding leads to presentist-friendly truthmaking and supervenience principles. In Sect. 5, I address some potential objections.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
Two caveats. First, we might exempt necessary truths, as they are true irrespective of the world—see Fine (2005) for discussion. Second, every proposition is, properly speaking, itself a part of the world. We might then modify Grounding to say that, for every contingently true proposition P, P depends for its truth on the world (other than the truths themselves). For simplicity, I mostly ignore these complications, as they are largely tangential to the grounding argument. But see Sect. 4 on the first point.
I use italics to denote propositions, e.g., that no unicorns exist.
Note that Truthmaker entails TSB but not vice versa.
More precisely, presentism is the view that, necessarily, it’s always true that only present things exist. I use a bolded expression, e.g. ‘exist’ or ‘is’, to emphasize a tenseless usage. What is it to exist? I take tenseless existence (or, alternately, existence simpliciter) to be what is expressed in first-order logic by the unrestricted quantifier, ‘∃x’. To ask whether a dinosaur or the Eiffel Tower or the number three exist is simply to ask whether there are any such things, full stop. Some are skeptical of an irreducible notion of tenseless existence. On the skeptical view, tenseless existence is either an incoherent notion (perhaps we can only talk about what exists in a tensed manner) or else is coherent but reducible to a tensed notion (perhaps something exists just in case it did, does, or will exist). But if the skeptic is right, then either presentism cannot be coherently formulated (since the presentist’s claim is that only present things exist), or else presentism is trivially false (since plenty of non-present things did and will exist). Since skepticism renders the grounding issue pointless, I here assume that it’s false. For further discussion of these points, see Crisp (2003), Meyer (2005), Savitt (2006), Sider (2006, 2001, pp. 15–17). For some defenses of presentism, see Bigelow (1996), Crisp (2003), and Markosian (2004).
Since it’s controversial whether there are truths about the future, I’ll focus my examples on the past.
Some subtlety is needed. Suppose that some facts are concrete. If so, tensed-facts presentists may choose to treat their tensed grounding facts as sui generis entities, lest they potentially commit themselves to a presentist-unfriendly ontology of ordinary concrete past and future things.
I use ‘how the world is’ as shorthand for ‘the things that exist and the instantiation pattern of properties and relations’ (and mutatis mutandis for ‘how the world was’ and ‘how the world will be’).
Tensed-fact and ersatz presentists of course do think that past-, present-, and future-tense truths supervene on how the world is. But these varieties of presentism involve telling a metaphysical story. My point is that before it occurs to her to tell a story, the presentist has no prima facie reason to think that all truths supervene on how the world is.
Or, more carefully, these principles are equivalent modulo truths about objects that exist outside of time. That is, perhaps there are truths about atemporal things, truths that depend on how the world is but not on how the world was, is, or will be. I ignore such truths since they seem to make no difference to the grounding argument.
Sanson and Caplan (2010) argue along similar lines. They restrict their attention to the presentist’s ideological challenge of accounting for “the properties and relations that things once instantiated”, whereas I am concerned also with the presentist’s ontological challenge of accounting for the things that once existed.
I assume that the presentist employs tense operators to construct past- and future-tense propositions from present-tense (or tenseless) ones. Thus, that there were dinosaurs is constructed by embedding that there are dinosaurs within the past-tense operator, WAS. Accordingly, WAS(that there are dinosaurs) is grounded just in case that there are dinosaurs was grounded.
Since the distinction between tensed and tenseless existence and between tensed and tenseless property instantiation is a metaphysically-nuanced distinction, it is not a distinction that one would expect to be tracked in pre-theoretical belief. I am not claiming that it is impossible that this distinction be tracked in pre-theoretical belief, only that it would be surprising if it were.
In this respect, the P-Grounding presentist view is structurally different from the tensed-fact and ersatz presentist views. These latter views, if successful, may convince eternalists that presentists have the ontological resources to ground truth. My goal here is thus a modest one: it is to show how presentists may reasonably resist the grounding argument, not to show how presentists may bring eternalists over to their side.
Again, modulo truths about atemporal entities.
Note that WAS(ψ) is to be read as equivalent to the proposition that something existed in one world but not the other or else some object instantiated a property or a relation in one world but not the other. And mutatis mutandis for WILL(ψ). In other words, Presentist TSB is to be read as saying that the truths supervene on what did, does, and will exist, plus the instantiation pattern that did, does, and will hold.
Need we add as a premise that if Elvis was 72 inches tall and Napoleon was 67 inches tall, then Elvis was taller than Napoleon was? Not if we assume a classical picture of entailment on which Q entails P just in case ¬◊(Q & ¬P). On classical entailment, we needn’t list necessary truths as premises.
Even supposing that the entailment strategy is plausible, another objection to the presentist’s treatment of (4) lurks. Namely: If that Elvis was taller than Napoleon was is true, then Elvis must have once stood in the taller than relation to Napoleon. So presentists face a dilemma: Either implausibly say that this proposition is false or else implausibly say that the existing Elvis once stood in a relation to the non-existent Napoleon. Two observations. First, the dilemma is not obviously a grounding worry, for it never calls into question presentists’ ability to give (4) a truthmaker. Second, the worry seems to confront all presentists (including tensed-fact and ersatz presentists), not just those who accept my view of grounding. For discussions of how presentists might treat cross-temporal truths, see Crisp (2005), Davidson (2003), and De Clercq (2005).
See Armstrong (2003), Restall (1996), and Rodriguez-Pereyra (2006) on the relationship between entailment and truthmaking. Armstrong defends, and Rodriguez-Pereyra attacks, the notion that truthmaking is closed under entailment: If T is a truthmaker for P and P → Q, then T is a truthmaker for Q. But note that Entailment and Entailment* are distinct from this stronger entailment principle; grounding may be closed under entailment even if truthmaking is not.
Note that clause (i) ensures that every necessary truth counts as grounded, for, trivially, anything whatsoever necessitates the truth of a necessary truth. Was Entailment* then all for naught? No. This is just the necessary truths problem of Truthmaker—viz. anything whatsoever counts as a truthmaker for any necessary truth—coming to bite Presentist Truthmaker under a slightly different guise. I’ll leave it to the truthmaker theorist to solve (or explain away) the problems with necessary truths (and negative existentials), and I’ll assume that a proposed solution that modifies Truthmaker can be imported to Presentist Truthmaker.
Perhaps there are no good presentist-friendly accounts of casual and temporal relations. If so, presentism is unattractive, and there is little point in answering the grounding argument. For discussion of presentist-friendly views of causation (and cross-temporal relations broadly), see Crisp (2005), Davidson (2003), and De Clercq (2005).
But let me suggest some promising leads. Reductionist (i.e. “Humean”) views on which casual truths are reducible to non-causal truths are presentist-friendly so long as the truths constituting the reduction base are presentist-friendly. A popular Humean view is Lewis’s counterfactual theory; see Lewis (2004, 1973). If one eschews a reductive approach, there are other presentist-friendly options. Bigelow (1996) suggests that the causal relation links propositions rather than events, and Huemer and Kovitz (2003) treat causal chains as involving temporally-overlapping events.
This plausibly assumes that the earlier than relation is existence-entailing: Necessarily, if a is earlier than b, then a and b both exist.
Presentists cannot believe that concrete things stand in cross-temporal relations, but perhaps they can believe that abstract things do (or, rather, that abstract things stand in a relation analogous to a temporal relation). Bourne (2006) and Crisp (2007) counsel presentists to treat times as abstract objects (i.e. “ersatz times”).
For the universe to instantiate a property, the contents of the universe must (on standard views of property instantiation) compose a single object denoted by ‘the universe’. Do they? It seems to be a feature of ordinary language that we often treat ‘the universe’ as picking out a single, maximal object. And notice that we need not believe in unrestricted mereological composition in order to think that the contents of the universe compose a maximal object; rather, we simply need a principled reason to think that they compose such an object. Cameron (2008) makes this latter point.
References
Armstrong, D. (2003). Truthmakers for modal truths. In H. Lillehammer & G. Rodriguez-Pereyra (Eds.), Real metaphysics (pp. 12–24). London: Routledge.
Armstrong, D. (2004). Truth and truthmakers. Cambridge: Cambridge University Press.
Bigelow, J. (1988). The reality of numbers. Oxford: Clarendon Press.
Bigelow, J. (1996). Presentism and properties. In E. T. James (Ed.), Philosophical Perspectives (Vol. 10, pp. 35–52). Cambridge, MA: Blackwell.
Bourne, C. (2006). A theory of presentism. Canadian Journal of Philosophy, 36, 1–23.
Cameron, R. (2008). How to be a truthmaker maximalist. Noûs, 42, 410–421.
Cameron, R. (2011). Truthmaking for presentists. In K. Bennet & D. Zimmerman (Eds.), Oxford studies in metaphysics (Vol. 6). Oxford: Oxford University Press.
Crisp, T. (2003). Presentism. In M. Loux & D. Zimmerman (Eds.), The Oxford handbook of metaphysics (pp. 211–245). New York: Oxford University Press.
Crisp, T. (2005). Presentism and cross-time relations. American Philosophical Quarterly, 42, 5–17.
Crisp, T. (2007). Presentism and the grounding objection. Noûs, 41, 90–109.
Davidson, M. (2003). Presentism and the non-present. Philosophical Studies, 113, 77–92.
De Clercq, R. (2005). Presentism and the problem of cross-time relations. Philosophy and Phenomenological Research, 72, 386–402.
Fine, K. (2005). Necessity and nonexistence. In Modality and tense: Philosophical papers (pp. 321–354). New York: Oxford University Press.
Huemer, M., & Kovitz, B. (2003). Causation as simultaneous and continuous. The Philosophical Quarterly, 53, 556–565.
Keller, S. (2004). Presentism and truthmaking. In D. Zimmerman (Ed.), Oxford studies in metaphysics (Vol. 1, pp. 83–104). Oxford: Oxford University Press.
Kierland, B., & Monton, B. (2007). Presentism and the objection from being-supervenience. Australasian Journal of Philosophy, 85, 485–497.
Lewis, D. (1973). Causation. Journal of Philosophy, 70, 556–567.
Lewis, D. (2001). Truthmaking and difference-making. Noûs, 35, 602–615.
Lewis, D. (2003). Things qua truthmakers. In H. Lillehammer & G. Rodriguez-Pereyra (Eds.), Real metaphysics (pp. 25–42). London: Routledge.
Lewis, D. (2004). “Causation as influence”. Unabridged version. In J. Collins, N. Hall, & L. A. Paul (Eds.), Causation and counterfactuals (pp. 75–106). Cambridge, MA: MIT Press.
Markosian, N. (2004). A defense of presentism. In D. Zimmerman (Ed.), Oxford studies in metaphysics (Vol. I, pp. 47–82). Oxford: Oxford University Press.
Mellor, D. H. (1998). Real time II. London: Routledge.
Merricks, T. (2007). Truth and ontology. New York: Oxford University Press.
Meyer, U. (2005). The presentist’s dilemma. Philosophical Studies, 122, 213–225.
Molnar, G. (2000). Truthmakers for negative truths. Australasian Journal of Philosophy, 78, 72–86.
Rea, M. (2003). Four-dimensionalism. In M. Loux & D. Zimmerman (Eds.), The Oxford handbook of metaphysics (pp. 246–280). New York: Oxford University Press.
Restall, G. (1996). Truthmakers, entailment, and necessity. Australasian Journal of Philosophy, 74, 331–340.
Rodriguez-Pereyra, G. (2005). Why truthmakers. In H. Beebee & J. Dodd (Eds.), Truthmakers: The contemporary debate (pp. 17–32). New York: Oxford University Press.
Rodriguez-Pereyra, G. (2006). Truthmaking, entailment, and the conjunction thesis. Mind, 115, 957–982.
Sanson, D., & Caplan, B. (2010). The way things were. Philosophy and Phenomenological Research, 81, 24–39.
Savitt, S. (2006). Presentism and eternalism in perspective. In D. Dieks (Ed.), The ontology of spacetime. Oxford: Elsevier.
Sider, T. (2001). Four-dimensionalism: An ontology of persistence and time. New York: Oxford University Press.
Sider, T. (2006). Quantifiers and temporal ontology. Mind, 115, 75–97.
Tooley, M. (1997). Time, tense, and causation. Oxford: Oxford University Press.
Acknowledgments
For many helpful comments, thanks to Dave Barnett, Tom Crisp, Josh Dever, Dan Korman, Adam Pautz, Mark Sainsbury, Michael Tooley, and an anonymous referee for this journal. I gave a version of this paper at the Philosophy of Time Society meeting in Vancouver; I’m grateful to the audience and to the meeting organizer, Nathan Oaklander.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Baia, A. Presentism and the grounding of truth. Philos Stud 159, 341–356 (2012). https://doi.org/10.1007/s11098-011-9711-8
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11098-011-9711-8