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.

Academics as border police

New rules on overseas students are being introduced by the Government, which will involve academics having to report to the Border Agency when such students have missed a certain number of contact hours. If you are a British citizen or resident and think it is not our role to act as immigration officers, that such rules threaten the autonomy of Universities, that they will make it harder for us to attract overseas students, or that this is generally a Bad Idea, please sign the petition below:


Monday, November 24, 2008

Job: deadline this Friday

Just a last reminder that the deadline for applications for the lecturer or senior lecturer at Leeds (in US terms, roughly equivalent to a tenured assistant or associate prof respectively) is THIS FRIDAY (28th).

For details on how to apply, see the post below.

Wednesday, November 12, 2008

Leeds job: reminder

Just a reminder that the deadline for the lecturer/senior lecturer position at Leeds is Nov 28th: just over two weeks from the time of posting.

AOS is open over all areas of the department, but we're particularly interested in applicants working in Theoretical Philosophy (broadly construed: so logic, phil logic, phil language, epistemology, metaphysics, phil of maths, phil mind etc) or the history of philosophy.

For the job ad go here (and scroll down a bit).

Friday, October 17, 2008

Schaffer on truthmakers and ontological commitment

In a few places, I've argued that Quine was wrong about ontological commitment. If you want to know what a sentence is ontologically committing to, look not to what the quantifier must range over, say I, but to what must exist to make it true.

Jonathan Schaffer replied in his 'Truthmaker Commitments'. He argues that the motivations for my view are bad ones and goes on to offer some objections to it. He does argue that truthmakers play a role though: but it's not in identifying the ontological commitments, but in identifying what is fundamental according to the theory.

I've just written my reply. I argue that the motivations are good ones, and I aim to counter the objections. I hope the view becomes a bit clearer in my responses to the objections - certainly, they forced me to say some things I hadn't said in the paper Schaffer is criticising. I end, though, by suggesting that it's not obvious there's a genuine dispute between me and Schaffer - that we just mean something different by 'ontological commitment'.

Comments, of course, would be welcome.
Update: the paper has been revised as of 18/10/08

Tuesday, October 14, 2008

Blind refereeing - request for info

Here's something you don't learn in grad school - probably because it isn't an issue until after you've been publishing for a bit. When submitting a paper, you make it suitable for blind review. Usually, that's really easy: just delete self-references, your name, acknowledgements (well, the latter isn't always done - but I think it should be), etc. But what if you're responding to a paper that is itself responding to you? Do you still need to prepare it for blind review? That would be much more work and might significantly change the tone of the paper, because while you might say things like 'I was unclear: what I meant was . . .' or 'X has misunderstood me' or 'I would respond thus . . .', you would have to hedge everything: 'perhaps Cameron meant . . .', 'Cameron might respond', etc. I'd be interested to hear from people who have experience of writing such replies whether that's what they do or whether they ignore the request to prepare the paper for blind refereeing in such cases (or whether they do something else).

Wednesday, September 17, 2008

Necessity and triviality

I’ve posted a new draft paper 'Necessary truth, truthmaking and triviality'. The main motivation of the paper is to defend the view that the necessary truths are all and only the trivial truths. A secondary motivation is to argue that, given truthmaker theory, this entails that the necessary truths are exactly the truths that lack a truthmaker.

A sentence is trivially true if and only if its truth makes no demand on the world. That is to say, its truth-conditions are trivially met. Nothing is required of the world for the truth conditions of a trivial truth to be met. Crucially, this is not the same as saying that the world meets the demands that the truth of the sentence imposes on it as a matter of necessity. It is conceptually consistent that the truth of a sentence makes demands on the world that the world necessarily meets. The substantial claim defended in this paper is that there are no such truths: all substantial truths (ones whose truth makes a demand on the world) are contingent.

To make sense of the idea of a truth with trivial truth-conditions, we must have a non-modal understanding of ‘demands’. The demands the truth of a sentence makes on the world can’t simply be what must be the case if the sentence is true. That is independently plausible: even if there are necessary existents such as numbers, or God, we should want an understanding of ‘demands’ such that the truth of ‘Socrates is a philosopher’ demands that Socrates exist and be a philosopher, but not that God or the number 2 exists. Indeed, I argue in the paper that if you only have a modal understanding of ‘demands’ there are a bunch of apparent conceptual possibilities that you simply can’t make sense of. Now if it makes sense that the truth of a sentence not demand that p be the case, even when p is necessary, we can make sense of the idea that the truth of the sentence makes no demands at all.

I argue that such trivial truths must be necessary, lest we violate a very weak version of the principle that truth is grounded in reality (one far weaker than the truthmaker principle). In that case we have an explanation for the necessity of at least some necessary truths: they are necessary because trivial. I further argue that if this is true we should hold that all necessary truths are trivial, lest we admit unexplained necessitites.

This has real consequences for certain debates in metaphysics. It settles the debate over whether there could have been no concrete objects, since ‘there are concrete objects’ is a substantial truth (it demands that there be concreta), hence a contingent one. It motivates, I argue, in favour of states of affairs as opposed to tropes as the truthmakers for contingent intrinsic predications. That is because ‘If the state of affairs of A being F exists, A is F’ is trivially true if true whereas ‘If the particular redness of A exists, A is red’ is substantially true if true (since more is required for A’s existence than that one of A’s properties exist, whereas since A is a constituent of the state of affairs of A being F, the conditions for A’s existence are already met in meeting the conditions for the existence of the state of affairs), and so only the former can be necessary – and given truthmaker necessitarianism, whichever is true is necessarily true.

(I want to give a shout out to Agustin Rayo. I've been much inspired and influenced by his recent work on truth-conditions, ontological commitment, etc. Go to his webpage and read 'On Specifying Truth-Conditions', 'Ontological Commitment' and 'Towards a Trivialist Account of Mathematics'. It's all really excellent stuff, and will give you an idea of the background I'm operating with in this paper.)

Tuesday, September 02, 2008

Permanent lecturer/senior lecturer at Leeds

Leeds is hiring again. We're seeking to appoint a lecturer or senior lecturer - AOS open, but we'd be especially keen on applicants with AOS in Theoretical Philosophy (broadly construed: i.e. phil logic and language, metaphysics, epistemology, phil mind, etc) or the history of philosophy.

Here's the ad:

University of Leeds

Faculty of Arts

Department of Philosophy

Lectureship/Senior Lectureship in Philosophy

(Available from 1 September 2009)

The Department of Philosophy is one of the largest Philosophy
departments in the UK, with around 30 academic staff and a
large intake of students. In recent evaluations it received a
maximum 24 for Teaching Quality and a rating of 5 in the 2001
Research Assessment Exercise. The Department includes the
Centre for History and Philosophy of Science,
the Centre for Ethics and Metaethics and the Centre for
Metaphysics and Mind.

The ‘Area of Specialisation’ for this position is open
across all areas of the Department but we are particularly
interested in applicants working in the areas of Theoretical
Philosophy (broadly construed) or History of Philosophy.

The position will incorporate undergraduate and postgraduate
teaching, some thesis supervision, and usual non-teaching duties.
With a strong record of research publication, the successful
candidate should be qualified to masters level or equivalent.
A PhD prior to application and teaching experience are strongly
preferred for a Lectureship and are essential for a position at
Senior Lecturer level.

For general information see http://www.philosophy.leeds.ac.uk/

University Grade 7 (£30, 912 - £33,780 p.a.) or University 8
(£34,792 - £41,545 p.a.) or University Grade 9
(£42,791 - £49,606 p.a.)

Informal enquiries to Professor Steven French: S.R.D.French@leeds.ac.uk

To download an application form and job details please visit
www.leeds.ac.uk and click on ‘jobs’.

Job ref 321001 Closing date 28 November 2008

Interviews will take place on 14/15 January 2009

Applicants should submit the completed application form,
full CV, and a writing sample (of no longer than 25 pages)
by the closing date of 28 November.

Tuesday, August 26, 2008

Vagueness and Naturalness

I've posted a draft of a new short paper on vagueness. I want a view of vagueness that upholds both classical logic and bivalence. I commit, then, to saying that there is a sharp cut-off between the things that satisfy any vague predicate and the things that don't. Williamson secures that by accepting the claim that our usage is fine grained enough for our predicates to latch onto a particular meaning, and that we'd have meant something different had we used the term ever so slightly differently. Like many, I don't find that plausible. Instead, I want to let the other factor that determines meaning do the work: naturalness. The claim I defend is that for any vague predicate there are a bunch of meanings that fit equally well with use, but that one is always the most natural. This is the one we mean, and this determines where the cut-off is: we can't know where the cut-off is because we have no naturalness detector. I explore extending this to arbitrary reference. The idea is that when we say 'Let 'n' be an arbitrary number', 'n' refers to the most natural number. And so on: so I secure bivalence at the cost of some heavy duty metaphysical claims concerning naturalness. It then becomes weighing up the costs and benefits.

But my real view is that the naturalness facts are themselves ontically indeterminate. There is a most natural meaning for 'is bald', but the world hasn't settled which of the candidate meanings is the most natural. In that case, while it is settled that there is a sharp cut-off between the bald and the non-bald things, it is ontically indeterminate where the sharp cut-off is. There is a most natural number that 'n' refers to; but it is ontically indeterminate which one it is.

Comments welcome!

Thursday, July 24, 2008

Branching time (x-post from TnT)

I've recently discovered some really interesting papers on how to think about belief in a future with branching time. Folks are interested in branching time as it (putatively) emerges out of "decoherence" in the Everett interpretation of standard Quantum mechanics.

The first paper linked to above is forthcoming in BJPS, by Simon Saunders and David Wallace. In it, they argue for a certain kind of parallel between the semantics for personal fission cases and the semantics most charitably applied to language users in branching time, and argue that this sheds lights on the way that beliefs should behave.

Now, lots of clever people are obviously thinking about this, and I haven't absorbed all the discussion yet. But since it's really cool stuff, and since I've been thinking about related material recently (charity-based metasemantics, fission cases, semantics in branching time) I thought I'd sit down and figure out how things look from my point of view.

I'm sceptical, in fact, whether personal fission itself (and associated de se uncertainty about who one will be) will really help us out here in the way that Saunders and Wallace think. Set aside for now the question of whether faced with a fission case you should feel uncertain which fission-product you will end up as (for discussion of that question, on the assumption that it's indeterminate which of the Lewisian continuing persons is me, see the indeterminate survival paper I just posted up). But suppose that we do get some sense in which, when you're about to fission, you have de se uncertainty about where you'll be, even granted full knowledge of the de dicto facts.

The Saunders-Wallace idea is to try to generalize this de se ignorance as an explanation of the ignorance we'd have if we were placed in a branching universe, and knew what was to happen on every branch. We'd know all the de dicto truths about multiple futures---and we would literally be about to undergo fission, since I'd be causally related in the right kind of ways to multiple person stages in the different futures. So---they claim---ignorance of who I am maps onto ignorance of what I'm about to see next (whether I'm about to see the stuff in the left branch, or in the right). And that explains how we can get ignorance in a branching world, and so lays the groundwork for explaining how we can get a genuine notion of uncertainty/probability/degree of belief off the ground.

I'm a bit worried about the generality of the purported explanation. The basic thought there is that to get a complete story about beliefs in branching universes, we're going to need to justify degrees of beliefs in matters that happen, if at all, long after we would go out of existence. And so it just doesn't seem likely that we're going to get a complete story about uncertainty from consideration of uncertainty about which branch I myself am located within.

To dramatize, consider an instantaneous, omniscient agent. She knows all the de dicto truths about the world (in every future branch) and also exactly where he is located---so no de se ignorance either. But still, this agent might care about other things, and have a certain degree of belief as to whether, e.g. the sea-battle will happen in the future. The kind of degree of belief she has (and any associated "ignorance") can't, I think, be a matter of de se ignorance. And I think, for events that happen if at all in the far future, we're relevantly like the instantaneous omniscient agent.

What else can we do? Well---very speculatively---I think there's some prospect for using the sort of charity-based considerations David Wallace has pointed to in the literature for getting a direct, epistemic account of why we should adopt this or that degree of belief in borderline cases. The idea would be that we *mimimize inaccuracy of our beliefs* by holding true sentences to exactly the right degrees.

A first caveat: this hangs on having the *right* kind of semantic theory in the background. A Thomason-style supervaluationist semantics for the branching future just won't cut it, nor will MacFarlane-style relativistic tweaks. I think one way of generalizing the "multiple utterances" idea of Saunders and Wallace holds out some prospect of doing better---but best of all would be a degree-theoretic semantics.

A second caveat: what I've got (if anything) is epistemic reason for adopting certain kinds of graded attitude. It's not clear to me that we have to think of these graded attitudes as a kind of uncertainty. And it's not so clear why expected utility, as calculated from these attitudes, should be a guide to action. On the other hand, I don't see clearly the argument that they *don't* or *shouldn't* have this pragmatic significance.

So I've written up a little note on some of these issues---the treatment of fission that Saunders-Wallace use, the worries about limitations to the de se defence, and some of the ideas about accuracy-based defences of graded beliefs in a branching world. It's very drafty (far more so than anything I usually put up as work in progress). To some extent it seems like a big blog post, so I thought I'd link to it from here in that spirit. Comments very welcome!

Update: Oh, and worldle abstract:

Indeterminate survival: in draft (x-post from TnT)

Update: I posted this over at Theories and Things, but I feel for it's MV posting I should give the Wordle Abstract for the draft paper:

On with the post:

So, finally, I’ve got another draft prepared. This is a paper focussing on Bernard Williams’ concerns about how to think and feel about indeterminacy in questions of one’s own survival.

Suppose that you know that you know there’s an individual in the future who’s going to get harmed. Should you invest a small amount of money to alleviate the harm? Should you feel anxious about the harm?

Well, obviously if you care about the guy (or just have a modicum of humanity) you probably should. But if it was *you* that was going to suffer the harm, there’d be a particularly distinctive frisson. From a prudential point of view, you’d be compelled to invest minor funds for great benefit. And you really should have that distinctive first-personal phenomenology associated with anxiety on one’s own behalf. Both of these de se attitudes seem important features of our mental life and evaluations.

The puzzle I take from Williams is: are the distinctively first-personal feelings and expectations appropriate in a case where you know that it’s indeterminate whether you survive as the individual who’s going to suffer?

Williams thought that by reflecting on such questions, we could get an argument against account of personal identity that land us with indeterminate cases of survival. I’d like to play the case in a different direction. It seems to me pretty unavoidable that we’ll end up favouring accounts of personal identity that allow for indeterminate cases. So if , when you combine such cases with this or that theory of indeterminacy, you end up saying silly things, I want to take that as a blow to that account of indeterminacy.

It’s not knock-down (what is in philosophy?) but I do think that we can get leverage in this way against rejectionist treatments of indeterminacy, at least as applied to these kind of cases. Rejectionist treatments include those folks who think that characteristic attitudes to borderline cases includes primarily a rejection of the law of excluded middle; and (probably) those folks who think that in such cases we should reject bivalence, even if LEM itself is retained.

In any case, this is definitely something I’m looking for feedback/comments on (particularly on the material on how to think about rational constraints on emotions, which is rather new territory for me). So thoughts very welcome!

Primitivism about indeterminacy: a worry (x-post from TnT)

I’m quite tempted by the view that it is indeterminate that might be one of those fundamental, brute bits of machinery that goes into constructing the world. Imagine, for example, you’re tempted by the thought that in a strong sense the future is “open”, or “unfixed”. Now, maybe one could parlay that into something epistemic (lack of knowledge of what the future is to be), or semantic (indecision over which of the existing branching futures is “the future”) or maybe mere non-existence of the future would capture some of this unfixity thought. But I doubt it. (For discussion of what the openness of the future looks like from this perspective, see Ross and Elizabeth’s forthcoming Phil Studies piece).

The open future is far from the only case you might consider—I go through a range of possible arenas in which one might be friendly to a distinctively metaphysical kind of indeterminacy in this paper—and I think treating “indeterminacy” as a perfectly natural bit of kit is an attractive way to develop that. And, if you’re interested in some further elaboration and defence of this primitivist conception see this piece by Elizabeth and myself—and see also Dave Barnett’s rather different take on a similar idea in a forthcoming piece in AJP (watch out for the terminological clashes–Barnett wants to contrast his view with that of “indeterminists”. I think this is just a different way of deploying the terminology.)

I think everyone should pay more attention to primitivism. It’s a kind of “null” response to the request for an account of indeterminacy—and it’s always interesting to see why the null response is unavailable. I think we’ll learn a lot about what the compulsory questions the a theory of indeterminacy must answer, from seeing what goes wrong when the theory of indeterminacy is as minimal as you can get.

But here I want to try to formulate a certain kind of objection to primitivism about indeterminacy. Something like this has been floating around in the literature—and in conversations!—for a while (Williamson and Field, in particular, are obvious sources for it). I also think the objection if properly formulated would get at something important that lies behind the reaction of people who claim *just not to understand* what a metaphysical conception of indeterminacy would be. (If people know of references where this kind of idea is dealt with explicitly, then I’d be really glad to know about them).

The starting assumption is: saying “it’s an indeterminate case” is a legitimate answer to the query “is that thing red?”. Contrast the following. If someone asks “is that thing red?” and I say: it’s contingent whether it’s red”, then I haven’t made a legitimate conversational move. The information I’ve given is simply irrelevant to it’s actual redness.

So it’s a datum that indeterminacy-answers are in some way relevant to redness (or whatever) questions. And it’s not just that “it is indeterminate whether it is red” has “it is red” buried within it – so does the contingency “answer”, but it is patently irrelevant.

So what sort of relevance does it have? Here’s a brief survey of some answers:

(1) Epistemicist. “It’s indeterminate whether p” has the sort of relevance that answering “I don’t know whether p” has. Obviously it’s not directly relevant to the question of whether p, but at least expresses the inability to give a definitive answer.

(2) Rejectionist (like truth-value gap-ers, inc. certain supervaluationists, and LEM-deniers like Field, intuitionists). Answering “it’s indeterminate” communicates information which, if accepted, should lead you to reject both p, and not-p. So it’s clearly relevant, since it tells the inquirer what their attitudes to p itself should be.

(3) Degree theorist (whether degree-supervaluationist like Lewis, Edgington, or degree-functional person like Smith, Machina, etc). Answering “it’s indeterminate” communicates something like the information that p is half-true. And, at least on suitable elaborations of degree theory, we’ll then now how to shape our credences in p itself: we should have credence 0.5 in p if we have credence 1 that p is half true.

(4) Clarification request. (maybe some contextualists?) “it’s indeterminate that p” conveys that somehow the question is ill-posed, or inappropriate. It’s a way of responding whereby we refuse to answer the question as posed, but invite a reformulation. So we’re asking the person who asked “is it red?” to refine their question to something like “is it scarlet?” or “is it reddish?” or “is it at least not blue?” or “does it have wavelength less than such-and-such?”.

(For a while, I think, it was was indeterminate, one couldn’t know p (think of parallel discussion of “minimal” conceptions ofassumed that every series account of indeterminacy would say that if p vagueness—see Patrick Greenough’s Mind paper). If that was right then (1) would be available to everybody. But I don’t think that that’s at all obvious — and in particular, I don’t think it’s obvious the primitivist would endorse it, and if they did, what grounds they would have for saying so).

There are two readings of the challenge we should pull apart. One is purely descriptive. What kind of relevance does indeterminacy have, on the primitivist view? The second is justificatory: why does it have that relevance? Both are relevant here, but the first is the most important. Consider the parallel case of chance. There we know what, descriptively, we want the relevance of “there’s a 20% chance that p” to be: someone learning this information should, ceteris paribus, fix their credence in p to 0.2. And there’s a real question about whether a metaphysical primitive account of chance can justify that story (that’s Lewis’s objection to a putative primitivist treatment of chance facts).

The justification challenge is important, and how exactly to formulate a reasonable challenge here will be a controversial matter. E.g. maybe route (4), above, might appeal to the primitivist. Fine—but why is that response the thing that indeterminacy-information should prompt? I can see the outlines of a story if e.g. we were contextualists. But I don’t see what the primitivist should say.

But the more pressing concern right now is that for the primitivist about indeterminacy, we don’t as yet have a helpful answer to the descriptive question. So we’re not even yet in a position to start engaging with the justificatory project. This is what I see as the source of some dissatisfaction with primitivism – the sense that as an account it somehow leaves something unimportant explained. Until the theorist has told me something more I’m at a loss about what to do with the information that p is indeterminate

Furthermore, at least in certain applications, one’s options on the descriptive question are constrained. Suppose, for example, that you want to say that the future is indeterminate. But you want to allow that one can rationally have different credences for different future events. So I can be 50/50 on whether the sea battle is going to happen tomorrow, and almost certain I’m not about to quantum tunnel through the floor. Clearly, then, nothing like (2) or (3) is going on, where one can read off strong constraints on strength of belief in p from the information that p is indeterminate. (1) doesn’t look like a terribly good model either—especially if you think we can sometimes have knowledge of future facts.

So if you think that the future is primitively unfixed, indeterminate, etc—and friends of mine do—I think (a) you owe a response to the descriptive challenge; (b) then we can start asking about possible justifications for what you say; (c) your choices for (a) are very constrained.

I want to finish up by addressing one response to the kind of questions I’ve been pressing. I ask: what is the relevance of answering “it’s indeterminate” to first-order questions? How should I alter my beliefs in receipt of the information, what does it tell me about the world or the epistemic state of my informant?

You might be tempted to say that your informant communicates, minimally, that it’s at best indeterminate whether she knows that p. Or you might try claiming that in such circumstances it’s indeterminate whether you *should* believe p (i.e. there’s no fact of the matter as to how you should shape your credences on the question of whether p). Arguably, you can derive these from the determinate truth of certain principles (determinacy, truth as the norm of belief, etc) plus a bit of logic. Now, that sort of thing sounds like progress at first glance – even if it doesn’t lay down a recipe for shaping my beliefs, it does sound like it says something relevant to the question of what to do with the information. But I’m not sure about that it really helps. After all, we could say exactly parallel things with the “contingency answer” to the redness question with which we began. Saying “it’s contingent that p” does entail that it’s contingent at best whether one knows that p, and contingent at best whether one should believe p. But that obviously doesn’t help vindicate contingency-answers to questions of whether p. So it seems that the kind of indeterminacy-involving elaborations just given, while they may be *true*, don’t really say all that much.

Tuesday, July 22, 2008


Via Robbie, I've discovered the genius source of amusement that is Wordle.

Update: Okay, I've become completely addicted. Here are the ones I've saved so far.

Truthmaking for Presentists

The Open Future

Truthmakers and Ontological Commitment

The Contingency of Composition

Turtles All the Way Down

Truthmakers, Realism and Ontology

On The Source Of Necessity

And here is Elizabeth's: Ontic Vagueness

Friday, July 18, 2008

Quantification, Naturalness, Ontology

I’ve posted a draft of a paper ‘Quantification, Naturalness, Ontology’; this is slated for the volume New Waves on Metaphysics, edited by Allan Hazlett – but there’s a while until the deadline, so any comments on it would be really helpful. Here are some of the main themes, on which I’d be grateful to hear thoughts. (These are here condensed and presented without much argument; for further info, obviously, see the paper.)

Thesis 1: As in previous work, I’m concerned with defending a distinction between what there is and what there really is. Following Sider, in order to resist neo-Carnapianism we should insist that there’s a unique most natural existential quantifier: one that carves the world along its quantificational joints. But, there’s no need to say that the ordinary quantifiers of English are this natural quantifier. Naturalness is a reference magnet, to be sure, but it can be trumped by use. But we can introduce a quantifier (‘there really is . . .’) stipulated to be the most natural quantifier. As long as you’re happy with the naturalness talk in the first place, there’s now no mystery in saying that what there is might come apart from what there really is.

Thesis 2: I defend a two-dimensionalist approach to sentences like ‘there is a table’. Considering the universalist world as actual, this sentence requires a table as a truthmaker, and so considering other worlds as counterfactual, we should only judge the sentence to be true at those worlds if they contain certain complex objects, namely tables. But considering the nihilist world as actual, the charitable thing to say is not that that sentence is false but that it requires for its truth only the existence of simples arranged table-wise, and so considering other worlds as counterfactual, we should judge the sentence to be true at a world iff it contains simples arranged table-wise. An attractive consequence is this: assuming (which I hope is the case) that the nihilist world is actual, we have a nice explanation for what many people think is a necessary truth, the necessity of which otherwise looks mysterious, namely: if there are simples arranged table-wise then there is a table.

Thesis 3: It’s right to take Moorean truths about what there is as inviolable. What’s wrong, however, is to read the ontology straightforwardly off of them. The truth of ‘Here is a hand’ is indeed on a stronger footing than any conjunction of premises that entails its falsity. But that doesn’t mean that, e.g., compositional nihilism is false. Compositional nihilism, properly understood, is the claim that no complex objects really exist, and that is compatible with the claim that there are complex objects like hands. The proper methodology is to ask what are needed as the ontological grounds for the Moorean truths. There are no Moorean truths about what there really is.

Thesis 4: The problem of the many is easy. There’s a unique cat on the mat. But asking which collection of particles is the cat, is a bad question. There isn’t really a cat. You can only ask, which collection of particles grounds the fact that there is a cat? Answer: all of them (i.e. all the collections which the universalist thinks are candidates for being the cat). But that doesn’t mean that there are many cats, of course – the one sentence can have multiple grounds.

Thesis 5: Since the ontological commitments of a sentence are its ontological grounds, it’s an open possibility that there are true sentences that lack ontological grounds and hence carry no commitments. I suggest that the truths of mathematics are like this. It’s true that there is a prime number between 8 and 12; but it’s a mistake to think that this is ontologically committing to numbers. (And no ‘paraphrase’ of the sentence into something not quantifying over numbers is necessary to say this.) Mathematical claims are trivial in the sense that they make no demands, a fortiori no ontological demands, on the world. (Cf. what I say here to what Agustin Rayo says in his defence of mathematical trivialism in this excellent paper.)

Thesis 6: Actually not a thesis. I tentatively speculate that one could reduce necessity in the following way: p is necessary iff p lacks an ontological ground. Obviously, not everyone’s going to think this is extensionally adequate, since some think contingent negative existentials lack a ground, and others think everything has a ground, including necessary truths. But I think it looks quite hopeful, and would like to hear whether or not anyone else does.

In other news, Elizabeth and my paper (“Elizabeth and my” – is that right? It sounds terrible, but I can’t think what else it should be.) on the open future has been accepted by Phil Studies. But we’d still appreciate any comments on it, as it’s an issue we’re hopefully going to keep working on.

Thursday, July 10, 2008

Metaphysics postdoc at Leeds

Leeds will be hiring a one-year research postdoc in metaphysics (broadly construed) for the academic year 08-09. The post is partially sponsored by the Centre for Metaphysics and Mind.

To apply on line please visit http://www.leeds.ac.uk and click on ‘jobs’, then 'research' (it will be listed as being in the school of humanities, not the department of philosophy). Alternatively, go here. Or application packs are available via email recruitment@admin.leeds.ac.uk or tel+44 (0)113 343 5771. The closing date for applications is August 6th, and interviews will be held in the week beginning Aug 25th.

For US readers: postdocs in the UK are not like in the US. They are a nice gig. There are very minimal teaching or admin duties, so you've basically got a year of research on a decent salary.

Please forward the details on to any potentially interested parties.

PhD studentship in Theoretical Philosophy

PhD studentship available at Leeds: please pass on to any potentially interested parties:

The Department of Philosophy, University of Leeds, intends to offer a Studentship in Theoretical Philosophy to a suitably qualified candidate for its full-time or part-time PhD programme. The studentship is tenable for 3yr (f-t) or 6yr (p-t) from October 2008 and has both tuition and maintenance components: the tuition component will be equivalent to the full EU PhD fee (currently £3.3k p.a. f-t) and the maintenance component will be equivalent to that of the AHRC Doctoral award (currently £12.6k p.a. f-t).The award is conditional on successful application for admission to study for PhD in the Department. However, applicants need not apply for admission prior to application for this studentship. Renewal of the studentship each year is subject to satisfactory progress towards PhD completion.
The successful applicant will undertake a PhD project in the area of Theoretical Philosophy broadly construed and will be supervised by Dr.Robert Williams, Reader in Theoretical Philosophy (http://www.philosophy.leeds.ac.uk/Staff/JRGW/index.html). For a range of preferred research topics, see link there to Dr.Williams' personal home page.
The Department operates a professional training and development scheme for postgraduates: as part of this scheme, successful applicants are often given the opportunity to undertake teaching, which is paid at an hourly rate. The Department also offers its PhD students financial support for conference attendance.
Applications should consist in 6 copies of a CV which includes a 500 word PhD-proposal: applicants should also arrange for 2 academic referees to submit references directly to the Department.
All applications and references should be marked Studentship in Theoretical Philosophy, and addressed to Ms Jenneke Stevens, Postgraduate Secretary, Department of Philosophy, University of Leeds, Leeds LS2 9JT, UK email j.m.stevens@leeds.ac.uk tel 0113 343 3263 fax 0113 343 3265.

Closing date 15 August 2008.

The University of Leeds promotes excellence in teaching, learning and research.
We welcome applications from all sections of the community.
All information is available in alternative formats - please contact 0113 343 5771.

Saturday, July 05, 2008

Presentism and Relativity

Familiarly, presentism faces an objection from special relativity. According to special relativity, so the objection goes, there is no such thing as absolute simultaneity: events that are simultaneous according to some reference frame are not simultaneous according to another. As a result, what counts as the present is different from one reference frame to another. If presentism is true, then, what exists must vary from one reference frame to another. But this is uncomfortable. Let us spell this argument out in a bit more detail.

1) There is no such thing as absolute simultaneity. (Premise from special relativity.)
2) Only the present time exists. (Premise from presentism.)
3) Only presently existing things exist, and only presently occurring events are occurring. (From 2.)
4) The present time is the time that includes all and only what is simultaneous with your reading of this . (Analytic of ‘the present time’.)
5) What is simultaneous with this utterance varies from one reference frame to another. (From 1.)
6) What things exist, and what events are occurring, varies from one reference frame to another. (From 3, 4 and 5.)

Presentism looks unacceptable then insofar as special relativity and what we might call ontological absolutism – the claim that what things exist, and what events are occurring, is absolute and not relative to anything; a fortiori it is not relative to a reference frame – are both acceptable.

What does the presentist need to do to meet this objection? A sufficient condition for meeting it, presumably, is that they give some reason for privileging one reference frame over any other; for in that case they can claim simply that what exists is what is simultaneous with your reading of this according to the privileged reference frame. What is simultaneous with your reading of this according to non-privileged reference frames is neither here nor there: there is no pressure to think these things exist unless they are simultaneous with your reading of this according to the unique privileged reference frame.

But how can the presentist have a reason for thinking that one reference frame is privileged (without resorting to claiming that God smiles upon one and not the others)? What could ground the privileged status of one reference frame over another, given that the physical facts don’t appear to distinguish between them?

I hear that question as a question about truthmakers. What we need is a truthmaker for the claim that some reference frame is privileged. If there is some ontological ground for distinguishing one reference frame from the others – some thing or things that mark to pick out one reference frame – then we can, without being arbitrary, take that reference frame to be the privileged one: the one that reveals what there is. So what might the truthmaker be for the fact that some reference frame is the privileged one?

Remember that, for the presentist, to exist is to be present. So consider all the events that exist – they are all and only the presently occurring events. So surely the privileged reference frame is just that one according to which exactly these events are simultaneous. In that case the truthmaker for the fact that this is the privileged reference frame is just what makes it true that those events exist – namely, those events.

So the thought is this. Everyone in this debate agrees that there is a unique set, S, which is the set of the existing entities. (That just follows from the assumption of ontological absolutism, and if you reject that then there is no problem in the first place.) This lets us single out a unique reference frame: the unique reference frame according to which exactly the members of S are simultaneous. And so, if we’ve got good reason to think that everything that exists is present then we’ve got good reason to think that this frame is the privileged reference frame. Since everything in S exists then everything in S is present; so they had better be simultaneous; so the reference frame that says they are simultaneous (and that nothing outwith S is simultaneous with any of them) is obviously the privileged one.

I imagine that seems way too quick. But ask yourself what the demand against the presentist is. It’s not that they must be able to discover what is present. The preceding remarks do not help the presentist do that. It may be in principle impossible for the presentist to know what exists because it is in principle impossible for them to know if their reference frame is the privileged one. But the objection against the presentist wasn’t epistemic, it was ontological. The objection wasn’t that discovering what is present, and hence what exists according to the presentist, is made difficult because there is no absolute simultaneity; the objection was that there is no absolute fact of the matter as to what is present, and hence no absolute fact of the matter as to what exists according to the presentist, because there is no absolute simultaneity. That is what I think is answered by the preceding remarks: insofar as we have reason to think that there is an absolute fact of the matter as to what exists, the presentist has reason to think that there is an absolute fact of the matter as to what is present, since granting the presentist that there is a unique set of existing entities allows them to uniquely specify a reference frame – the reference frame according to which they are all only the present things. What other reference frame could be a candidate for being privileged, given that the presentist thinks that to exist is to be present?

(And the epistemic objection doesn’t seem too worrying to me in any case. It seems to reduce to: you can’t know what exists, because you can’t know if you’re in the privileged reference frame. But why is that any better than any of the myriad sceptical challenges that aim to undermine your knowledge by showing that there are empirically equivalent possibilities where you get it wrong?)

I think the objection against the presentist has seemed more forceful than it is due to the assumption that the presentist should be able to pick out a unique reference frame independently of picking out the class of existing entities. But why hold that assumption? It’s not as if those entities exist in virtue of that reference frame being privileged. If that were the case then it may well be objectionably circular to presuppose their existence in an explanation of why that reference frame is privileged. But existence facts are, plausibly, brute: when it is true that a exists it is true solely in virtue of a. So the existence of the members of S can be taken for granted in any metaphysical explanation we choose to give - indeed, if the truthmaker theorist is right, all explanation comes to a halt when, and only when, we reach propositions concerning what the members of S are.

The members of S don’t exist because they are all present according to the privileged reference frame; rather, it is that reference frame that is privileged because it is the one according to which all and only the members of S are present. All of us, presentist and non-presentist alike, have to simply accept as brute the existence of some entities. For the non-presentist, accepting a set of things whose existence is brute does not serve to privileged one reference frame, but that is precisely because they don’t accept that to exist is to be present. For the presentist, however, these entities must be present, because everything is present, and so it follows immediately that only a reference frame according to which all and only these things are simultaneous is one that gets things right. Since we are sure of at least one thing that it is present – namely the reading of this sentence – and since there is a unique reference frame according to which that event is simultaneous with exactly the members of S, we know that that reference frame is the privileged one.

The argument from relativity might have force against other versions of the A-theory – such as the moving spotlight or growing block views – that postulate a privileged present without saying that what it is to exist is to be present. Such views require a privileged frame of reference but can’t say that it is the frame of reference according to which all the existing things co-exist: that frame of reference would get things wrong since both views admit the existence of past entities as well as present ones. And so they need another answer as to what grounds the privileged status of the reference frame that gets things right, and it’s not clear what they can say. But presentism, I think, faces no problem: and so this is one reason to think that presentism is the best version of the A-theory available.

Sunday, June 22, 2008

Perspectives on Ontology - registration deadline

The deadline to register for Perspectives on Ontology (July 1st) is fast approaching; so if you want to come to this fantastic conference, you'd better send your registration in asap!

Details here:

www.personal.leeds.ac.uk/~phlrpc/Perspectives on Ontology.htm

Sunday, May 18, 2008

Truthmakers, presentism and indeterminacy

In my ‘Truthmaking for Presentists’ paper, I end up defending the following 2 theses:

1) Truths concerning what was or will be the case are grounded by the presently existing world instantiating a distributional property – I’ll call it a world history – that says how it is across time.
2) The asymmetry of fixity – that the past is fixed and the future is open – is to be explained as follows: there is a non-empty non-singleton set, S, of candidate world histories, such that it’s determinate that exactly one of them is instantiated by the present world but not determinate of any member of S that it is instantiated by the present world. The candidate properties ‘agree’ on how the past was and ‘disagree’ on how the future will be, which is why propositions concerning the past are fixed whilst those concerning the future are unsettled.

This raises a bunch of questions: What makes it the case that the present candidates for being our world’s world history are the present candidates for being our world’s world history? What change in being has there been between yesterday and now that accounts for the fact that there are fewer candidate world histories? What is the difference in being between our world and a world whose past is like ours but which has a less open future? What makes it true that it’s determinate that a member of S is the world history of our world? What makes it true that it’s indeterminate of any particular member of S that it is the world history of our world?

These questions raise issues concerning how the truthmaker theorist should deal with propositions of the form ‘(In)determinately, p’, which I’ve been thinking about recently.

There are two broad approaches to answering these questions. On the first approach, propositions of the form ‘Determinately, p’ or ‘It’s indeterminate whether p’ get treated just like any other. On this view, there will be some truthmaker for ‘Determinately, p’, some thing which can’t exist and p not be determinately true, and some truthmaker for ‘It’s indeterminate whether p’, some thing which can’t exist and p have a determinate truth-value.

This approach will, perhaps, be favoured by those who hold that there is no gap between truth and determinate truth. On this view, it’s safe to simply identify the truthmaker for ‘determinately, p’ with the truthmaker for p: all God has to do to make p a determinate truth is to make p true, so any thing that makes p true will make it true that p is determinately true. On this view, indeterminacy leads to a truth-value gap, and so a truthmaker for ‘It’s indeterminate whether p’ can be thought of simply as something whose existence necessarily excludes the existence both of any truthmaker for p and any truthmaker for not-p.

I, however, hold that there is a gap between truth and determinate truth. More has to happen for the world to be such that p is determinately true than that p is true. If truth doesn’t entail determinate truth, what more is needed of ontology to make p determinately true than is needed to make it merely true? I reject the answer that says there must be an additional truthmaker for ‘Determinately, p’: rather, I say that the truthmaker for p must simply be a determinate existent rather than a mere existent.

If God wants to make sure that p is not only true but determinately true, He doesn’t need to add another entity to the world, in addition to the truthmaker for p, that will make it true that p is determinately true. Rather, all He needs to do to ensure that p is not merely true but determinately true is ensure that the truthmaker for p not only exists but determinately exists, (or at least that it’s determinate that a truthmaker for p exists – He needn’t make it determinate of a particular truthmaker for p that it exists). If God wants to make a world where p is indeterminate, He should create a world where it’s indeterminate whether a truthmaker for p or a truthmaker for not-p exists. And if He wants to create a world where p is true but indeterminate, He should create a world where there is a truthmaker for p but where it doesn’t determinately exist (and nor is it determinate that there is any truthmaker for p).

The idea is that propositions expressed by sentences involving the determinacy or indeterminacy operators don’t themselves get matched up to possible truthmakers. Rather, the ‘(in)determinacy free’ propositions that are their constituents get matched up to possible truthmakers, and the ‘(in)determinacy involving’ propositions get their truth-value bases on whether those truthmakers determinately exist, determinately don’t exist, exist but don’t determinately exist, or don’t exist but don’t determinately not exist.

Traditionally, the truthmaker theorist thinks that in order to fix exactly what is true, God simply has to decide what to create. On the view under offer, this isn’t quite right. Deciding what to create fixes the truth-value of the ‘(in)determinacy free’ propositions; but to further fix the truth-values of the ‘(in)determinacy involving’ propositions, God has to do one more thing: decide which of the things He’s decided to create are to exist determinately and which are to exist but not determinately exist., and decide which of the things He’s decided not to create are to determinately not exist and which are to not exist but not determinately not exist. Once He’s done that, he’ll have settled everything there is to settle.

Let’s return to the questions we asked earlier regarding the candidate world histories. Presumably, what would make it true that H is the world history of our world would be the state of affairs of our world instantiating H. In the normal run of things – when we’re not dealing with indeterminacy – explanation can stop here; we don’t have to admit an additional entity to make it true that the state of affairs of our world instantiating H exists: the state of affairs itself makes that true. Everything makes true the fact that it itself exists, so once we’ve reached the facts concerning what truthmakers exist, we’ve reached the level of facts where explanation comes to a halt.

But in the above context, where it is indeterminate which member of S is the world history of our world, it must be indeterminate what state of affairs exists. Suppose S just has two members: H1 and H2. Then here are three truths:

1) It is indeterminate whether H1 is the world history of our world
2) It is indeterminate whether H2 is the world history of our world
3) It is determinate that exactly one of H1 and H2 is the world history of our world

The truth of (1) – (3) entail the truth of (4) – (6) below:

4) It is indeterminate whether the state of affairs of our world instantiating H1 exists
5) It is indeterminate whether the state of affairs of our world instantiating H2 exists
6) It is determinate that exactly one of the state of affairs of our world instantiating H1 or the state of affairs of our world instantiating H2 exists.

On the approach I rejected, we now need truthmakers for (4) – (6). I suggest abandoning this approach. Intuitively, the difference in being between a world in which (4) is true and a world in which it is false is simply the difference in the status this state of affairs has in both worlds: in one it has determinate existence, in the other it lacks determinate existence (without going so far as to have determinate non-existence). Doesn’t that sound like difference in being enough? Why should we feel the need to postulate something outside of this state of affairs that exists at one world and accounts for the state of affairs’ determinate existence and which doesn’t exist at the world where the state of affairs does not determinately exist?

On the view I advocate, there are no truthmakers for (4) – (6). (4) – (6) are brute truths; explanation comes to a halt here. If p is indeterminately true then what grounds this is that it is indeterminate whether a truthmaker for p exists; but that it is indeterminate that such a truthmaker exists is not itself something that demands a truthmaker.

Is this revisionary? It’s not clear to me that it is, and I certainly think that it’s in the spirit of truthmaker theory. Truthmaker theory just is a theory about what truths are brute. The only brute truths, says the truthmaker theorist, are truths about what there is: explanation only comes to an end when we reach the ontological inventory. Now, if there’s no indeterminacy in the world, then it’s natural to characterise such truths as all being of the form ‘X (the Xs) exist(s)’. But if it can be indeterminate what exists, then it’s not clear why ‘It is indeterminate whether Y exists’ should be grounded in some truth of the form ‘X exists’: there is a perfectly good sense in which ‘It is indeterminate whether Y exists’ is about what there is, and hence is exactly the kind of truth that truthmaker theory allows us to take as brute. ‘It is indeterminate whether Y exists’ is not about how Y is, it’s about whether Y is: it belongs with ‘Y exists’ and not with ‘Y is F’, in that it is a truth simply about what should go on the ontological inventory and not a truth about how the things that are on the ontological inventory are. To put this another way: being indeterminately existent is no more a property than being existent, and so attributing indeterminate existence to an entity is no more to say something about how that entity is than attributing existence to it: both attributions are to do with whether the entity is, not how it is, and so if one can acceptably be taken as brute, so can the other.

The truthmaker theorist is fond of theological metaphors: all God has to do to fix what is true is to fix what exists. I agree. And if He wants to make a proposition p determinately true he will make sure to make the corresponding portion of ontology that makes p true determinately existent (or at least make it determinate that there is a corresponding bit of ontology), whereas if He wants to make it indeterminate whether p is true, He will make it indeterminate whether that portion (or indeed, any such portion) of ontology exists. He does not need to thereby add more ontology to the world to make it true that this portion of ontology determinately or indeterminately exists: His fixing that it determinately or indeterminately exists is part of His fixing what there is.

Consider two presentist worlds, wc and wo. Since they are presentist worlds, they consist of one time only: call it t. But both worlds are such that they will last for exactly one more instant after t and haven’t existed before t. Both worlds will be such that they have lasted for two instants, then. They both contain one entity, a, which exists throughout the duration of the world; which is just to say that a exists at t and that it will persist into the next instant. At t, the first instant of each world (the present instant), a is F. In wc (the closed world), it is settled at t that a will remain F in the second instant. In wo (the open world), it is unsettled at t whether a will remain F in the second instant or whether a will cease to be F.

What does God have to do to make wc? He has to take a and the distributional property of being F and then (in the next instant) F and put them together in the state of affairs of a having this distributional property: call it SC. He then has to make this state of affairs a determinate existent. Were wc actual, it would be true that a will be F, and this would be made true by SC; furthermore, in this closed world, a’s future is settled: it is determinately true that a will be F, and the truth of this is secured by the fact that SC doesn’t just exist but rather exists determinately.

Making wo is a little more complicated for God. As a first step, He’ll need the distributional property of being F and then (in the next instant) not-F, and the state of affairs (call it SO) of a having this property. He then needs to decree that it is determinate that exactly one of SC or SO exists, but that it is indeterminate that SC exists and indeterminate that SO exists. This suffices to ensure that, were wo actual, it would be open what will happen to a: it will be determinate that a is F (since it’s determinate that a truthmaker for ‘a is F’ exists, since it’s determinate that one or other of SC and SO exist, and the existence of either will make it true that a is F), but it will be determinate whether or not a will be F in the future (since it’s indeterminate whether there’s a truthmaker for ‘a will be F’, since one of the candidate world histories would make that true and the other won’t).

But God’s job isn’t done yet. For suppose wo is actual. Once we wait an instant, we’ll be able to see whether a is F in the second instant of wo’s history, and this will reveal whether the proposition ‘a will be F’ was true at t. Suppose a does in fact remain F. In that case, a’s history in the two worlds is just the same: it’s just that in one world its history was open and in the other it was closed. At t in both worlds, what lies ahead in the future for a is the same: it’s just that in one world it is settled that this is what lies ahead for a, and in the other world it’s not settled that this is a’s future, because there are genuine alternatives that are not ruled out. So God needs to do one last thing to make wo: He needs to make SC exist. He just needs to be careful that in doing so He doesn’t make it determinately exist!

wo and wc, then, are exactly alike with respect to what ‘(in)determinacy free’ propositions are true, and differ solely with respect to the truth-value of propositions of the form ‘Determinately, p’ or ‘It is indeterminate whether p’. And this leads to exactly what you’d expect on the view under offer: they are exactly alike with respect to what exists, and differ only as to whether some of the things that exists determinately exist and whether some of the things that don’t exist determinately don’t exist. SC exists at both worlds and SO doesn’t exist at either world; but in wc SC is a determinate existent and SO a determinate non-existent, whereas in wo it’s neither determinately the case that SC exists or determinately the case that it doesn’t exist, and likewise for SO. On the other hand, a is a determinate existent at both worlds, and SX, the state of affairs of a having the distributional property being not-F and then (in the next instant) F, determinately doesn’t exist at both worlds.

So, I’d love any feedback on the above approach. I’d also really appreciate any thoughts on my response to the following potential objection.

Objection: “What you’re doing, basically, is allowing more truths as brute than simply those of the form ‘such-and-such exists’. You’re also allowing as brute truths of the form ‘Determinately, p’ or ‘Indeterminately, p’ provided that p is itself a truth of the form ‘such-and-such exists’. But if we’re allowed to do that with the determinacy operators, what’s the bar on doing that with temporal operators? That is, why can’t we allow as brute truths of the form ‘WAS, p’ or ‘WILL BE, p’, provided that p is itself a truth of the form ‘such-and-such exists’? If, when characterising what God has to do to fix what is the case, we’re allowed to say that He makes A a determinate existent and B an indeterminate existent, why are we not allowed to also say that He simply makes C a past existent, D a future existent, etc. There’s no privileged difference that will allow you to take truths of the form ‘Determinately, A exists’ as brute and not truths of the form ‘It will be the case in a year’s time that B exists’; but if we can take the latter as brute, there’s simply no truthmaker objection to presentism, and so all of the above is unnecessary.”

Reply: I think there is a privileged difference. ‘Determinately, such-and-such exists’ is about what there is in a way that ‘WAS, such-and-such exists’ is not – it’s just about what there was.

The temporal (and modal, for that matter) operators ‘point beyond’ themselves in a way that the determinacy operators don’t. When I modify ‘A exists’ with a temporal or modal operator, I’m attributing to A the same kind of existence as if I simply said ‘A exists’, but I’m attributing this kind of existence to A not in the circumstances of utterance but at some point removed from the circumstances of utterance: I’m saying that A has the bog-standard mode of existence – but it doesn’t have it here, it has it some distance along the temporal or modal dimension. By contrast, when I modify ‘A exists’ with a determinacy operator (by saying ‘Determinately, A exists’ or ‘It’s indeterminate whether A exists’) I’m making a claim about A’s existence in the circumstances of the utterance and instead modifying the mode of A’s existence.

To say that p is determinate or indeterminate is to say something about p’s status in our current circumstances, it’s not to ‘point beyond’ our current circumstances and say something about its status at circumstances removed from ours along some dimension in the way that we do when we say that p was or will be true, or that it could or must have been true. Determinate existence and not-determinate existence are types of existence a thing can have in the current circumstances; necessary or contingent existence, or temporary or eternal existence (e.g.), are not modes of existence – a necessary/eternal existent exists in the same way as a contingent/temporary existent, it just does so at every point across the modal/temporal dimension. Whereas when I say that something is a determinate existent, this is not to say (contra Akiba) that that thing exists at every point across some ‘precisificational’ dimension , but to say something about how it exists in our circumstances.

That’s why I think it’s acceptable for the truthmaker theorist to take as brute truths concerning what determinately exists or exists but not determinately, etc, but not truths concerning what will or did exist, or what could or must exist. Only the former are truths concerning what there is; the latter concern not what there is, but only what there was or will be, or what there could or must be, and hence must be grounded in facts concerning what there is.

Wednesday, May 07, 2008

Jobs at Leeds

Leeds is advertising for two one-year lecturerships; one with a preferance for phil science, the other with a preferance for value/history. Details here.

These are quite nice gigs, because (unlike a lot of temporary jobs) your workload and teaching/admin duties will be just like that of any other member of staff, temporary or permanent - so the successful applicants will have the same amount of time dedicated for research as any other member of staff.

Wednesday, April 23, 2008

Neo-Carnapianism and triviality

So here's something that's been puzzling me, and I've made very little progress on. The neo-Carnapian holds that ontological debates are shallow. When two ontologists argue as to whether there are Fs, the neo-Carnapian says that this isn't a genuine ontological debate: that at worst these two theorists are simply talking past one another; at best their disagreement is merely linguisitc, over the correct usage of the English terms involved.

Now, it's obviously trivial that we could use the term 'exists' differently, so that 'there exists an F' would have had the opposite truth value from what it in fact has. We could have meant by 'there exists' what we in fact mean by 'there doesn't exist', for example. That's not interesting. So what is the neo-Carnapian thesis? Sider characterises it, correctly, as the doctrine that there are multiple meanings for the quantifier and that none of them is more natural than any of the others. (Either because there's no such thing as naturalness, or because there is and they're all equally natural.) Okay, but we just used a quantifier to state that: there are multiple meanings for the quantifier that are equally natural. So if neo-Carnapianism is true, wouldn't their own theory tell them that their theory is not a substantial theory: that is, one whose truth is sensitive not to the metaphysics but simply to what we mean by our words? If neo-Carnapianism is false, it's substantially false, but if it's true it's trivial (in one good sense of trivial).

Is that right? And if so, is it a problem for neo-Carnapianism? It's a strange dialectical position to be in, to hold a view that is trivial if true and substantially false if false, but it's not obviously incoherent.

(I've been considering a neo-Carnapian who thinks that all ontologiacal disputes are shallow; of course, many don't - Hirsch, for example, thinks disputes about the existence of complex objects etc are shallow, but not disuputes about the existence of, e.g., numbers and sets. So let the question be: does the above give us reason to reject global neo-Carnapianism: to hold that at least the question as to whether there is a most natural meaning for the quantifier is a substantive ontological question?)

Wednesday, April 02, 2008

Perspectives on Ontology - Register Now!

UPDATE: Registration details are now available for Perspectives on Ontology. Please see the website here.

Attendance at the conference is limited, so I urge early registration.

Details are also available for the graduate bursaries.

Perspectives on Ontology

A major international conference on metaphysics to be held at the University of Leeds, Sep 5th-7th 2008.

Karen Bennett (Cornell)
John Hawthorne (Oxford
Jill North (Yale)
Helen Steward (Leeds)
Gabriel Uzquiano (Oxford)
Jessica Wilson (Toronto)

Benj Hellie (Toronto)
Kris McDaniel (Syracuse)
Juha Saatsi (Leeds)
Ted Sider (NYU)
Jason Turner (Leeds)
Robbie Williams (Leeds)

There's also going to be a graduate conference directly prior to this. Details, including a call for papers, are available here.

Counterpart theory and the incarnation. Cos why not?

While I generally try and avoid the philosophy of religion unless I'm bored of an afternoon, this year I have been teaching 'metaphysical issues in religion', and so have been forced to get to grips with some of the issues.

One issue that's not been uninteresting is a familiar problem regarding God’s incarnation as the man Jesus Christ. Christ is both human and divine. This is to say that he has a human nature and a divine nature. As the Council of Chalcedon put it in 451AD, "the same Christ . . . [is] to be acknowledged in two natures . . . the characteristic property of each nature being preserved, and concurring in one person."

The threat is that this leads quickly to outright contradiction. Associated with the divine nature are properties of perfection, such as omnipotence, omniscience and omnibenevolence; but associated with the human nature is the absence of such perfections. Humans are neither omnipotent, omniscient nor omnibenevolent. And so we seem driven to saying that Christ both is omnipotent, omniscient and omnibenevolent (in virtue of being divine) and not omnipotent, omniscient or omnibenevolent (in virtue of being human): a contradiction three times over!

How to respond? One option is to deny that it follows from having a human nature that one doesn’t have any of the qualities of divine perfection. Certainly, it is no part of the human nature that a human have these qualities: but it hardly follows that in virtue of being human a thing must lack those qualities – being human might simply be silent as to the presence or absence of the divine perfections. In that case Christ’s humanity simply doesn’t speak to his having or lacking omnipotence, omniscience and omnibenevolence. As far as his human nature is concerned, it is simply an open question whether he has those properties or not. The door is closed, however, because of his divinity, which ensures that he does indeed have them. And so Christ simply has the divine perfections, and there is no threat of contradiction.

Such a view is taken by Thomas Morris. Morris distinguished between being wholly human and merely human. Christ is wholly human because he belongs to the kind human. And if it makes any sense to speak of things as partially belonging to a kind, Christ does not only partly belong to it, he wholly belongs to it. But he is not merely human. To be merely human is to have no more essential properties that what are guaranteed by being a member of the kind human; and Christ does have more, because he also has the properties that are guaranteed by his divinity.

This view avoids the paradox, but at a cost. There is a strong temptation to hold not only that being human doesn’t entail the possession of the divine perfections but that it entails their absence. To say otherwise, after all, is to invite the theologically immodest claim that even we mere humans might have been omnipotent, omniscient and omnibenevolent. We are not in fact as God is; but we could have been.

But also, there is some desire to be able to say that Christ the man lacked them. Think of Christ in Gethsemane: it appears for all the world to be the story of a man who is worried about the future. But why would such concerns arise unless Christ lacked knowledge about how things would turn out? Think now of Christ being tempted by Satan: it appears for all the world to be a story about a man overcoming temptation. But unless there was the possibility of his succumbing, there was nothing to overcome. And so the threat of contradiction is pressing. Christ, we want to say, is both limited and unlimited, both perfect and flawed. How can this be?

One thing we might be tempted to say is that Christ has the divine perfections qua God but not qua man. But what do such locutions mean? Well, there’s a familiar story about how that can be the case; and surprisingly it has received no discussion, to my knowledge, in this context. I want to put this option on the table: the option is counterpart theory.

Compare the case of Christ and omnipotence with a familiar case which is structurally analogous: the case of the statue and the clay. The clay can be squashed but the statue cannot. And yet many of us feel the pressure to say that there is only one entity here: the lump of clay simply is the statue. How, then, are we to avoid the absurdity that one and the same thing both has and doesn’t have the property of squashability?

As above, there is a temptation to say that this one thing is squashable qua lump of clay but not qua statue. But what does this mean? Counterpart theory gives us an answer. The properties of this one thing remain constant, but whether any of its properties deserve to be called the property of squashability depends on contextually variant factors, which means that whether or not the entity satisfies the predicate ‘. . . could be squashed’ can itself vary from context to context. When we speak of the one thing as the clay, this is enough to make salient the clay-ness of the entity, and in such a context one of the properties had by this entity deserves to be called the property of squashability, which is why we speak truly when we say that the clay could be squashed. When we speak of the one thing as the statue, on the other hand, this is enough to make salient the statue-ness of the entity, and in such a context none of the properties had by this entity deserves to be called the property of squashability – including the one previously correctly so described! This is why we speak truly when we say that the statue could not be squashed. And this is what we mean when we say that the entity can be squashed qua lump of clay but not qua statue.

That is enough to show that there need be no inconsistency in saying in one context that an entity satisfies some predicate and in another that it lacks it (despite not having undergone change): to generate an inconsistency one needs the further assumption that the property being picked out by that predicate is the same in both contexts. Since the predicate ‘. . . could be squashed’ is picking out a different property depending on whether the subject is referred to as the statue or as the clay, there is no inconsistency in saying that the statue couldn’t be squashed but that the clay could, even though they are one and the same thing. Likewise, if ‘. . . is omnipotent’, ‘. . . is omniscient’ etc pick out a different property depending on whether the subject is referred to as God or as man then there is no inconsistency in saying that Christ the man lacks omnipotence and omniscience etc and that Christ the God possesses them, even though the God is the man.

Omnipotence is a modal property like squashability: it is the property of being able to do anything possible. One needn’t actually do every possible action to be omnipotent, it simply has to be within one’s powers, which is to say that for any possible action one could do it. In that case, the counterpart theoretic solution can simply be carried over to the case of Christ and omnipotence. It is true to say that Christ the God is omnipotent and false to say that Christ the man is omnipotent. Why? Not because there are two entities, but because different standards of similarity are invoked depending on whether it is the divine or the human characteristics of one and the same entity that are made salient. If Christ’s divinity is salient then no possible being would count as dissimilar to Christ in virtue of doing some possible action – and so, for any possible action, there is a counterpart of Christ that performs that action, which is why Christ satisfies ‘. . . is omnipotent’. But if Christ’s humanity is salient then beings that perform miraculous feats like creating the universe ex nihilo don’t get to count as Christ’s counterparts, since humans just can’t do such things. And so, in this context, it will be true to say that there are things that Christ (the man) just couldn’t do, and thus true to say that he is not omnipotent.

Does the counterpart theoretic story carry over to the other divine perfections, such as omniscience and omnibenevolence? I think the prospects aren't terrible. It is easy to construe such predicates as being implicitly modal. It is no stretch of the imagination to suggest that to be omnibenevolent it is not enough simply to have managed not to actually do anything wrong: rather, one must have had the disposition to act rightly no matter what the circumstances. (You don’t get to be omnibenevolent by moral luck!) And so whether an object satisfies ‘. . . is omnibenevolent’ depends on whether or not that object has counterparts that do wrong things, and so the above story applies. Likewise with omniscience: it’s not enough simply to know all truths – the omniscient being would know even the propositions that are actually false, had those propositions been true. And in general, when we’re dealing with the divine perfections, they will concern not just how the bearer actually is but how it could have been. Perfection implies a counterfactual robustness – you don’t get to be perfect y accident. God’s perfection with respect to knowledge or power or etc concerns how he is and how he could and must have been: a being does not get to share in these properties by virtue of chance or luck. And as soon as one insists on counterfactual robustness one makes these predicates modal, which invites the counterpart theoretic solution to the threatening paradox.

What about God’s actual knowledge of all actual truths? Don’t we want to deny this to Christ the man as well? (Consider his apparent lack of knowledge, in Gethsemane, as to how the future would turn out.) If so, then to run the above story we must accept a modal account of what it is for an agent to know something. But this is not implausible. It’s what Ryle held, for example. x knows that p iff, roughly, x is disposed to act in a p-believing way in suitable circumstances. Now, of course, Ryle combined this with a behaviourism about the mental and an account of dispositions as brute truths; but we needn’t join him in either of those theses to find plausible the linking of knowledge ascriptions with ascriptions of some complex dispositional. It needn’t be an analysis of what it is for x to know that p for x to be disposed in a certain manner in order for the truth of the knowledge ascription to go hand in hand with the truth of the dispositional ascription. And if the truth of the knowledge ascription is sensitive to the truth of the dispositional ascription then context sensitivity in the latter will result in context sensitivity in the former. Christ the God can be correctly ascribed knowledge that p because all his relevant Godly counterparts act in a p-believing way when in the appropriate circumstances, but Christ the man cannot correctly be ascribed knowledge that p because he has manly counterparts that fail to exhibit p-believing behaviour even when prompted appropriately.

Here's an interesting consequence of the counterpart theoretic view: it commits us to saying that while the second person of the Trinity, God the Son, in fact incarnated as the man Jesus Christ, he might not have done. Counterpart theory, familiarly, commits us to the contingency of identity. The statue is in fact identical to the lump of clay, but it might not have been: had the lump of clay been squashed, it wouldn’t have been identical to the statue. Likewise, Christ the God, the second person of the Trinity, is in fact identical to Christ the man (who is also therefore, given Leibniz’s law, the second person of the Trinity). But Christ the God might not have been identical to Christ the man: had the man been flawed he wouldn’t have been identical to the God. And so whilst Christ the God is essentially the second person of the Trinity, Christ the man is only accidentally the second person of the Trinity.