CHAPTER 5. PRESENTISM AS SERIOUS PRESENTISM
5.6 A Possibility for Understanding Presentism?
We have seen that it is possible to infer from the claim that Everything exists at the present time
to the conclusion that
Only things that exist at the present time can exhibit properties or stand in relations, if we interpret the former claim as
Everything that ever did or ever will exist, exists at the present time.
I claimed in chapter 1, and several times in this chapter, that this seems obviously false, and presumably it is not what the presentist intends by her thesis.
In chapter 4, I pointed out that philosophers posit special entities, possible worlds, to explain why true statements about possibility and necessity are true. For a possibilist, a possible world might be a set of possible entities, perhaps members of a concrete world which is causally, spatially, and temporally isolated from this one, as in Lewis (1986). For an actualist, a possible world is something abstract (Van Inwagen 1986), like a possible arrangement of the fundamental entities which compose the world (D. M. Armstrong 1986) (Wittgenstein, Pears and McGuiness 2001), or a maximally consistent set of propositions, or a maximal states of affairs (Plantinga 1974). In any case, possible worlds are posited as explaining how some statements about what is merely possible can be true.
Along these lines, we might imagine a view according to which everything which ever did exist or ever will exist, exists at the present time, and at the present time (or outside of time) there exist certain objects in virtue of which some statements about ‘the past’ and ‘the future’ are true.
To the objection that the thesis that
Everything that ever did or ever will exist, exists at the present time
Is obviously false, someone who adopted this view might retort that this seems obviously false only because it is taken to entail that statements like “Dinosaurs roamed the earth” and “Plato wrote The Republic” are untrue. This assumption, however, is incorrect: although everything that ever did exist or ever will exist, exists at the present time, included among these things are entities which make these and various other statements about ‘the past’ and ‘the future’ true.
I must confess to finding this view unbelievable. It may not be impossible for everything which ever did exist, obtain, or occur to exist, obtain, or occur at a single time, for it may not be impossible for there to only ever be a single moment of time. However, I do not think a world like that could also contain entities like us. However, we should consider if any presentists might in fact believe just this.
In fact, serious presentists do rely on what exists at the present time (or outside of time) to explain why statements like “Dinosaurs roamed the earth” and “Plato wrote The Republic” can be true. I will briefly survey some of the proposals in the literature. It is not my intention here to either endorse or challenge any of these proposals. My intention, rather, is to see if it is likely that any presentists believe that everything that ever did or will exist, exists now, but some statements apparently about the way things were or will be, like “Dinosaurs roamed the earth,” and “There will be human colonies on Mars” are nonetheless true. I will conclude that there is no good reason to think that any actual presentists believe this.
Ludlow (1999) claims that the truth-maker for a given past-tensed statement is the presently existing evidence associated with that statement:
[W]hen we say that a proposition was true or will be true, exactly what are we getting at?
… [A] semantic theory that accounts for an agent’s semantic knowledge must show how portions of that language are learned from the evidence available to the language learner.
But now consider how we learn the use of past-tense expressions such as…
Dinosaurs roam the earth.
We do not evaluate this sentence by imagining some time earlier than now and determining whether at that time [this sentence] is true. Rather, we evaluate [this sentence] by right now conducting a sort of investigation that is appropriate for past-tensed statements like [it].
(For example, we might study fossil records). (Ludlow 1999, 98-99).
Ludlow goes beyond the epistemic claim that we look at presently existing evidence to decide the truth of past-tensed and future-tensed statements; rather, Ludlow claims that such evidence is what makes such statements true or false.82
According to Lucretian presentism (Bigelow 1996), the truth-makers for past-tensed statements are the tensed properties of presently existing objects. On this view, “Dinosaurs roamed the earth is true because the earth, or various locations on the earth, have the property being where some dinosaur roamed. The statement “Plato wrote The Republic” is true because some location has the property being where Plato wrote The Republic.
Some philosophers (Bourne 2006) (T. Crisp 2007) propose that the truth-makers for past-tensed statements are abstract objects, ersatz times, which stand in ersatz before and after relations to one another. These ersatz times are supposed to be somewhat analogous to propositions or possible worlds.
The versions of ersatzer presentism offered by Bourne and Crisp differ slightly. Crisp (2007) writes that an ersatz time is:
82 Eric Hiddleston points out that this is just verificationism.
A certain sort of maximal abstract object: intuitively, an abstract representation of an instantaneous state of the world. (T. Crisp 2007, 99)
Crisp expounds upon this as follows:
Let us think of a time as any proposition that satisfies the following definition:
x is a time = df. For some class C of propositions such that C is maximal and consistent, x
= [∀y(y ϵ C ⊃ y is true)],
where (i) a class C of propositions is maximal iff, for every proposition p, either p or its denial is a member of C, (ii) a class C of propositions is consistent iff, possibly, every member of C is true, and (iii) ‘[∀y(y ϵ C ⊃ y is true)]’, I assume, denotes a tenseless proposition. (T. Crisp 2007, 99-100)
Thus, for Crisp an ersatz time is a maximally consistent set of tenseless propositions which are true.
Bourne’s (2006) explication of his conception of ersatz times begins with a distinction between two types of present-tensed propositions. Those which contain past or future-tense operators, like “It is now the case that it was the case that Socrates is sitting” (Bourne 2006, 53), he calls embedded propositions or e-propositions. Those which do not contain past or future-tense operators, like “Socrates is sitting” (Bourne 2006, 53) he calls unembedded or u-propositions. On Bourne’s view ersatz times are construed using u-propositions:
I propose we construct times using maximally consistent sets of u-propositions, which intuitively we can see as those u-propositions that are true at that time. These propositions I take to give a complete, maximally specific, description of what is true at that time…
Times I take to be more than sets of present-tensed propositions: first, they consist of sets of u-propositions; second, they also contain a ‘date’. That is, I take times… to be ordered pairs of the form t = <μ, n ϵ ℝ>, where μ is a set of u-propositions and n ϵ ℝ is a date.
(Bourne, A Future for Presentism 2006, 53-54)
Thus, for Bourne an ersatz time is a maximally consistent set of unembedded tensed propositions and a date. On either construal, “Plato wrote the Republic” is true because a certain ersatz time represents Plato’s writing of The Republic.
Rhoda (Rhoda 2009) claims that the truth-makers for past-tensed statements are memories in the mind of God.
Such examples illustrate how serious presentist try to account for the truth of statements like “Dinosaurs roamed the earth” and “Plato wrote The Republic” utilizing only what exists at the present time or outside of time. It does not follow from this, however, that these philosophers believe that everything that ever did or ever will exist, exists at the present time. Indeed, Fiocco’s (2007) account of the truth of past-tensed statements seems to directly contradict this idea. Fiocco proposes that the truth-makers for past-tensed statements are a special class of timeless facts, which have their natures in virtue of what occurs at each successive moment in time.
One can construe facts as simple, that is, non-structured entities that, being immutable, do not exist in time. A specific fact would not have existed without the moment it is about; to this extent, facts depend on moments… Atemporal facts of this sort are the basis of truths about the past, as such they are the truth-makers of past-tensed statements. (O. M. Fiocco 2007, 193)
On this proposal, the truth-maker for “Plato wrote The Republic,” is an atemporal fact which exists and has the nature it has because there was a person, Plato, who wrote The Republic. Fiocco’s account for how past-tensed statements can be true thus appears to presuppose that there were times before the present moment.83
The proposal that everything which ever did or ever will exist, exists at the present time, but that some statements about ‘the past’ and ‘the future’ are still true seems absurd. It would be uncharitable in the extreme to interpret a philosopher as endorsing a view which seems obviously false, unless he or she endorsed that view explicitly, or unless it was a straightforward consequence of what he or she endorsed explicitly. However, no construal of presentism I have encountered in
83 Actually, I think Fiocco’s proposal is not really a version of serious presentism at all. For if “Plato wrote The Republic” is true because of a timeless fact, which has the features it does because during some previous time, Plato wrote The Republic, it seems that some relation holds between the sentence and Plato’s writing of The Republic, which is not occurring at the present time. However, without the assumption that presentism entails serious presentism, it is clear what would motivate Fiocco to posit such timeless facts as truth-makers.
the literature contains explicit commitment to the view discussed here. This thesis is stark enough that if anyone endorsed it, I suspect that he or she would be explicit about it. For that reason, I reject this way of trying to understand presentism as a substantive thesis.
5.7 Concluding Remarks
My goal in this chapter was to see if we could use serious presentism, according to which only things existing at the present time can exhibit properties or stand in relations, to help us understand presentism, according to which everything exists at the present time, as a substantive metaphysical thesis. I considered three arguments for the conclusion that presentism entails presentism, and I showed that each of these arguments could be undermined by the same basic strategy used in chapter 1 to argue for the conclusion that presentism is not a substantive thesis.
Then I considered the prospects for identifying presentism with the thesis that everything that ever did exist or ever will exist, exists at the present time, but that some statements apparently about the past and future are nonetheless true. I rejected construing presentism in this way, since it seems obviously false and is not, to my knowledge, endorsed by anyone.