Tuesday, November 25, 2008

Indeterminate truthmaking

Recently, I’ve been thinking a lot about how to think about truthmaker theory if there’s ontic indeterminacy. If you thought that p’s being indeterminate amounted to p’s lacking a truth-value and you were a truthmaker maximalist, your life would be quite easy: you could say that ‘p is indeterminate’ is true just because there’s neither a truthmaker for p not a truthmaker for not-p.

But I, following Elizabeth and Robbie’s work, have committed to the view of ontic indeterminacy whereby ‘p is indeterminate’ does not entail a truth-value gap. ‘Indeterminately, p’, on this bivalent view, is compatible with both the truth of p and the falsity of p. p is either true or false, it’s just unsettled which.

On this view, there’s a gap between truth and determinate truth, and it’s an interesting question in that case what the truthmaker theorist should say. One option is that ‘Indeterminately, p’ and ‘Determinately, p’ just get treated like any other proposition, and get assigned possible truthmakers, but I prefer the option that says we should assign possible truthmakers only to the ‘indeterminacy free’ propositions, and determine the truth-value of the ‘determinacy involving’ propositions based on whether those truthmakers determinately exist or exist but not determinately so.

So the idea is that, e.g., the state of affairs of Ball being red makes it true that Ball is red. And if it’s determinately true that Ball is red that’s not because there’s some further thing, the state of affairs of Ball being determinately red, but rather because the state of affairs of Ball being red is a determinate existent. The thought being that if p is determinately true at one world and true but not determinate at another, it is difference in being enough if the truthmaker for p is a determinate existent at the former world and a mere existent (one which exists, but not determinately so) at the latter. (You can think of this as a difference in the way that the truthmaker exists, or alternatively allow yourself extra ideology – see section 7 of this paper.)

Now, if every proposition got mapped onto exactly one possible truthmaker, life would be simple. But it doesn’t, and it’s not. p might be determinately true not because there is some truthmaker for p that determinately exists but rather because it’s determinate that there exists some truthmaker for p. The case I’m most interested in is the open future. If there’s a fixed past but open future then, I say (see my joint paper with Elizabeth), there’re a bunch of candidate states of the world being a certain way throughout history that agree on how things were and are but disagree on how things will be, and it’s determinate that exactly one of these states exists, but indeterminate which.

It’s determinate that young Earth creationism is wrong because there’s determinately a truthmaker for ‘Dinosaurs existed millions of years ago’ – but there’s no determinately existing truthmaker for that proposition. Each candidate state would make that true, and it’s determinate that one exists, so it’s determinate that it’s made true. ‘Martian colonies will exist in a hundred years’, on the other hand, is neither determinately true nor false, since if a certain candidate state exists it will be made true and if another exists it will be made false, and it’s not determinate which exists.

Exactly one of these candidate states gets things right – it gives us the actual history of the world – so that state exists and all the others don’t. But none of them get it determinately right or wrong, so the existent state is a mere existent and the non-existent states mere non-existents. But saying this doesn’t tell us that it’s determinate that exactly one of these states exists, so we need to either take that as a brute fact or admit a disjunctive state of affairs – the state of affairs of this world state existing or that world state existing or . . . etc – and proclaim it to be a determinate existent.

A decision has to be made when it comes to non-existence. Truthmaker theorists disagree as to whether to admit truthmakers for negative existentials or to let explanation bottom out at facts about what there is not as well as facts about what there is. But either way, the story is going to be more complicated once it can be indeterminate what there is.

Suppose a determinately exists, b exists but not determinately so, c fails to exist but not determinately so, and every other possible existent determinately fails to exist. If you are not a truthmaker maximalist and want to take facts about what there is not as brute you still have to be able to distinguish between the mere non-existence of c and the determinate non-existence of d (say). If you were inclined to believe in two ways of being – determinate and mere being – you should now postulate two ways of non-being – determinate and mere non-being. On this view, to completely determine a world, what God has to do is to say of every possible being which of the four ways of being or non-being it has: once He’s done that, He’ll have settled everything there is to settle. (At least provided that the disjunctive states of affairs mentioned above number amongst the possibilia.)

Now suppose we are attracted to maximalism. Since a and b are the only things there are, we must admit the existence of the second-order totality state of affairs of a and b being the only first-order things that there are. Now for Armstrong, you can stop there: there’s no need to posit an additional third-order totality state of affairs saying of the second-order totality state of affairs that it’s the only second-order totality state of affairs that there is; that’s because it’s necessarily true that there’s only one second-order totality state of affairs, and hence it can itself make it true that it’s the only one. And so there’s no risk of regress. But if it’s not determinate what there is, it will likewise not be determinate what second-order totality state of affairs exists. In our situation it’s not determinate that a and b are all the things there are: both the totality state of affairs of a being the only thing, and of a, b and c being the only things, are non-existents, but they are mere non-existents. However, since it’s determinate that exactly one of these totality facts exists we can’t stop at the postulation of the second-order totality state of affairs; we need to admit a new entity: the disjunctive state of affairs of one of these three totality states of affairs existing. And now we need another new entity – a third-order totality state of affairs – that says that everything we’ve talked about so far are all the things that exist at levels one and two. In essence, this third-order totality state of affairs is the thing that makes it true that all the candidate second-order totality states of affairs are all the candidate second-order totality states of affairs.

Now, our story can stop here if it’s necessarily true that whatever third-order totality state of affairs exists, it is determinately the only third-order totality state of affairs that exists. But if it’s possible for there to be higher-order indeterminacy in what there is – that is, if it’s possible that it’s indeterminate not just what the totality of entities is but what the candidate totalities are – then the third-order totality state of affairs itself may be a mere existent. There could be other candidate third-order totality states of affairs, and it not be determinate which of them exists. But it will be determinate that one of them does . . . and so we’re off on a regress. Now personally, I doubt the coherence of higher-order indeterminacy; I think that while it might be indeterminate what there is, it necessarily won’t be indeterminate what the range of candidate totalities are, and so I think the maximalist will be able to stop at the determinately existing third-order totality state of affairs and resist infinite regress.

Anyway, I go into all of this in more detail in sections 6 and 7 (and 8 to a lesser degree) of my Truthmaking for Presentists paper. If anyone has any comments on either what’s written here or there, I’d welcome them.

1 comment:

Priam's Pride said...

I have a comment for you, but my comment depends upon your ontological commitments. I am probably revealing my guilt at having not read the preceding chapters, but this is first time here.

So we are separating truth-values into two categories, the determinate truth values and the indeterminate truth values. Accordingly, we have the determinate states of affairs and the indeterminate states of affairs. It is evident that we have some overlap in states of affairs, though. I will take you to mean maximally comprehensive states of affairs that amount to the physical composition of the universe in a single instant. Of course, here you may or may not admit states of affairs as abstracta. In any case, the overlap between the two states of affairs are all those features in the world that are determinate and are determinately true. In your example, a.

The truth-value types "determinate" and "indeterminate" must be epistemological values. That is, what makes something determinately true is that it can be known to be true. So in splitting truth values into two types, you have already recognized that you have separated the world into two types of being: determinate being and mere being. Of course, this seems to be a moderate Kantianism. Your determinate being is very similar to Kantian phenomena and your mere being is very similar to Kantian noumena.

Of course, we are not yet in trouble for positing Kantian noumena -- we just have to be careful not to claim any knowledge about it (which Kant couldn't resist). It seems, though, that there is an ontological claim that you'll have to take a stand on.

You mention at the beginning of this section that "if it’s determinately true that Ball is red that’s not because there’s some further thing, the state of affairs of Ball being determinately red, but rather because the state of affairs of Ball being red is a determinate existent." Clearly "determinate existent" is in need of definition. You do not want the state of affairs itself to be an entity separate from the physical world, so it must be nothing more than a spatial time-slice of the existing physical universe. That is, a state of affairs is defined as physical -- a mere configuration of matter.

But it is problematic to take the logical step that you take later on, if states of affairs are not, in fact, abstracta. I quote:

"[W]e need to admit a new entity: the disjunctive state of affairs of one of these three totality states of affairs existing. And now we need another new entity – a third-order totality state of affairs – that says that everything we’ve talked about so far are all the things that exist at levels one and two. In essence, this third-order totality state of affairs is the thing that makes it true that all the candidate second-order totality states of affairs are all the candidate second-order totality states of affairs."

It is at this point that we are now trying to create a category containing both determinate beings and mere beings -- a mixed category. Thus, we will find that the class of determinate beings consists of {a}. The class of mere beings consists of {a, b} and the class of third-order totality beings consists of {a (determinately), a (merely), b (merely)}. In other words, you have created a new class of entities which consists of the composite of both determinate and mere entities.

The problem with this new category of beings is that it has physical overlap. So if your second-order state of affairs is nothing more than a spatial time-slice of the universe (i.e., a physical being), then it is perfectly identical to the third-order state of affairs which we have been positing.

To reiterate: We are clearly retaining states of affairs as truth-bearers, so these are the possible ontological commitments involved in doing so. (1) They are physical as described above. This entails that the third-order class of beings is really a pseudo-being, because physicalists generally accept the identity of indiscernibles. (2) They are abstract. This obviously entails that the state of affairs is, indeed, a separate being from the physical objects it describes, so this possibility is precluded. (3) They are mental. This last is a problematic avenue. As we shown above, the first order beings, the determinate beings or phenomena, are defined epistemically. This means that the beings which occupy the determinate realm are mental beings. Thus, a third order category would, if states of affairs are mental beings, create a mental category consisting of the mental and the physical (for the mere beings are physical). If we were to allow such a classification, we would invite a vicious order-regress involving the mixed classes of the phenomenal and the noumenal.

So it seems to me that it is just not possible to talk meaningfully about a third-order state of affairs that is not itself an abstract entity. It is, of course, easier to recognize that it is not possible to posit a third-order realm of being without abstracta.

Hopefully, I won't find out that I have misunderstood your claim to physicalism about states of affairs -- in which case you will have wasted your time with something you already knew.

-Priam's Pride