Sunday, February 01, 2009

Cameron on Merricks on Cameron on Merricks on Truthmakers

I've linked before to my contribution to a symposium on Trenton Merricks' book 'Truth and Ontology' (T&O). Merricks' reply (to me and my fellow symposiasts (?), Jonathan Schaffer and Scott Soames) can be found here. Obviously, in a symposium the author gets the final word. The good thing (and the bad thing) about a blog, though, is that there can always be another word! So here I'm going to respond to some of Merricks' replies to me.

A general style of argument that Merricks makes a few times in T&O runs as follows. If truthmaker theory is true then every truth has a truthmaker; the best candidates for truthmakers for the truths in domain D are the Xs; but we shouldn't believe in the Xs; therefore we shouldn't believe the truths in domain D have truthmakers; but we should believe they're true, therefore truthmaker theory is false.

Two instances of this argument schema plug in truths about the past and negative existentials for D and, respectively, Lucretian properties and totality facts in for the Xs. In my paper, I agree with Merricks that we shouldn't believe in Lucretian properties or totality facts, but I argue that the truthmaker theorist (even if she is a presentist) can do better in each case. Merricks argues that my candidate truthmakers shouldn't be believed in either. He also makes a te quoque against me, and argues that the reasons I give for not believing in Lucretian properties rule out my proposed truthmaker for negative existentials. I'll respond to these charges.

Let's take truths concerning the past first. Given the truth of presentism, what makes it true that I was once a child? The Lucretian says I have (presently) a purely past-directed property: the property of having once been a child. In 'Truthmaking for Presentists', I argued that what is peculiar about such properties is that an object's having them makes no difference to the intrinsic nature of the object at the time it instantiates it. We should only believe in a property F, I argued, if an object instantiating F at t makes a difference to how F is intrinsically at t. Lucretian properties don't make such a difference: they only make a difference to how the bearer was intrinsically – so we shouldn't believe in them. I argued that temporal distributional properties do better: an object's instantiating a temporal distributional property at t makes a difference to how the object is intrinsically at t (thus avoiding the charge of peculiarity facing the Lucretian) but it also makes a difference to how the object was intrinsically at the previous moments of its existence (thus solving the truthmaker problem).

Why might you not like this solution? Here's an inconsistent tetrad:

1) Presentism is true
2) Objects instantiate temporal distributional properties
3) If an entity instantiates a distributional property, it extends throughout the region across which that property distributes
4) If an object extends throughout a region of some dimension, the region of that dimension exists

From (2) and (3), objects extend through temporal regions. From (4) it follows that there are extended temporal regions, which contradicts (1), which entails that only a point of the temporal dimension exists.

Abandoning (1) or (2) would just be to reject my theory, so can either (3) or (4) plausibly be given up? In my contribution to the symposium, I suggested abandoning (4). I said the presentist has to abandon this anyway, since they believe in persisting objects, and these are objects which are extended throughout time, even though the regions of time throughout which they extend do not (according to the presentist) exist.

Merricks objects that "presentists should deny that existing at a time is anything like being located at a region . . . Similarly, presentists should deny that persistence is extension throughout a temporal region. . . So they should reject the view that persisting objects are extended throughout nonexistent regions."

The invocation of location at a (I presume spatial) region suggests that Merricks is thinking of my view as one where objects stretch throughout time just like they stretch throughout space, even though extended regions of time do not (unlike extended regions of space) exist. But certainly, I never urged the presentist to hold that view! The sense in which I claimed the presentist must hold that objects are extended throughout time is a trivial one: they must believe that there are objects which are not instantaneous existents – objects which do exist and either did or will exist at some past or future time. Call this extension through time. The presentist believes in the possibility of extension through time, in this sense, without extended regions of time existing. So in this sense of 'extension', (4) is definitely false, according to any sensible presentist. My point can basically be put as a challenge to those who see a tension between presentist and truthmaker theory: give me an argument that I should accept (3) for any sense of 'extension' stronger than this one. I grant (3) in this trivial sense of 'extension', but then (4) is obviously going to be denied by the presentist. And there are senses of 'extension' like the way an object extends through space which make (4) true, but then I don't see why I must accept the corresponding reading of (3). The burden of proof is on one who is pushing the inconsistent tetrad: tell me the sense of 'extension' you have in mind, and give me an argument as to why I should accept both (3) and (4) – until then, I'll continue to believe my account reconciles truthmaker theory with presentism.

Let's turn to negative existentials. Following this earlier paper, I argued that the truthmaker for claims of the form 'There are no Xs' is the world itself. The view is that each positive truth has a truthmaker, and that the world is essentially composed of all and only these truthmakers. Furthermore, the world is essentially maximal: it is necessarily a world, necessarily the largest thing there is – i.e. it is necessarily composed of all the truthmakers for the positive truths. So it can't be a proper part of any other thing. That means that, necessarily, the world can only exist if all and only the truthmakers for the positive truths are all and only the actual truthmakers for the positive truths. And so, since an actually true negative existential couldn't be false without some actually false proposition being a positive truth requiring a truthmaker, the world suffices as a truthmaker for all the true negative existentials.

Merricks objects to this proposal by objecting to the property of being a world. He says this is "a totality property, equivalent to being such that there is nothing more in the universe. So Cameron's world resembles the totality state by exemplifying a totality property essentially. . . Thus what Cameron calls 'the world' is nearly the same thing as the totality state." And hence I haven't really made any advance over Armstrong's totality states. And then there's the te quoque: the property being a world makes no difference to the intrinsic properties of its bearer at the time of instantiation, hence by my own lights (as seen above, RE Lucretianism) it's peculiar, and so my own principle tells us not to accept my own ontology. Ouch!

I think Merricks' objections here are misplaced. (In fairness, I should point out that he makes some others that I am not responding to here.) Merricks objects to the property of being a world. But I didn't appeal to any such property: I only appealed to the world!

I'm assuming the following kind of picture. The reason a truthmaker theorist admits properties into her ontology is to ground accidental predications. The reason we need to admit a property of being charged is to make true truths of the form 'X is charged' – but one only needs the property because X is merely accidentally charged: were X essentially charged, X itself would be an acceptable truthmaker for 'X is charged'. If every charged entity is essentially charged, we simply don't need to admit the property of being charged – the charged entities are ontology enough. It's only because the charged things might not have been charged that we need to admit the state of affairs of them being charged (which involves the existence of the property), to provide a necessitating truthmaker for the fact that they are charged.

There's only one thing that's a world, and it is essentially a world. So I deny that we need to admit a property of being a world. The world is ontology enough. That is why my view is perfectly compatible with the principle that mandates my rejection of Lucretian properties. It's also (one of the reasons) why I think I have an advantage over Armstrong's totality states view (for other reasons, see this paper): I am merely attributing a more robust essence (but in familiar ways) to an entity many of us already believe in – I am not introducing a peculiar property for the sole purpose of solving some truthmaker problem.

Finally, I'll say something about possibilism and modal truth. In T&O Merricks makes what seems to me a very odd claim: that admitting mere possibilia to ground truths concerning what might have been is no use, because both actualist and possibilist alike should, if they are to be truthmaker theorists, hold that what is actually true depends on what there actually is. Hence actual truths concerning what might have been must be grounded in actual ontology – and so admitting mere possibilia is no help to securing the truthmaker thought.

I see no reason why a possibilist who wants to be a truthmaker theorist should hold that actual truth depends on actual being. Actual truth is just truth, so this principle is just that truth depends on actual being. I think that should only be acceptable to a truthmaker theorist if they hold that actual being exhausts being simpliciter. The truthmaker thought, I think, is just that truth depends on ontology: and the truthmaker theorist should be able to appeal to whatever ontology they believe in, whether actual or merely possible, present or past, etc. The only reason for a truthmaker theorist not to appeal to the Xs to ground some truth is if they don’t believe in the Xs.

I made the following analogy to illustrate this. Would anyone think it a good demand that the truthmaker theorist ground truths concerning what goes on at other places only in ontology that exists here? I considered the proposition 'It's raining on the other side of the world', which is true in Australia. Should we demand that Armstrong account for this truth only by appealing to entities that are located in Australia? Surely not! Surely, Armstrong is at liberty to appeal to all the entities he believes in to ground this truth, no matter where in the world they happen to be located. Only a here-now-ist should believe that the only entities to be appealed to in truthmaking are ones that exist here.

Merricks objects to the analogy because he denies "that propositions are true at places". (He points out that were he an eternalist he would deny that propositions are true at times.) But I don't need to commit to propositions being true at places in any objectionable sense in order to make the analogy. My point is just that modal truths should be treated by the possibilist just like truths concerning what goes on at other places should be treated by all of us who deny here-now-ism. There's a perfectly good sense in which 'It's raining on the other side of the world' is true in Australia and not in the UK (given that it's raining in the UK, not raining in Australia, and that Australia is the other side of the world to the UK and vice-versa); there's a perfectly good sense in which 'Gordon Brown is now the Prime Minister of the UK' is true at the present time and not true 10 years ago; there's a perfectly good sense in which 'It's merely possible that there are talking donkeys' is true at this world and not at a world containing talking donkeys. Those are the pre-theoretic data; the philosophical work to be done is spelling out what this amounts to. I agree with what I take to be Merricks' thought: that what we should say in each case depends on what we think about the ontology of places, times and worlds, respectively. If you are a here-now-ist/presentist/actualist you should say that propositions are true at locations/times/worlds; if you are sensible/an eternalist/a possibilist you should say that the propositions expressed by these sentences at one location/time/world are different from the proposition expressed at a different location/time/world, and that the proposition expressed is true or false simpliciter, and not at a location/time/world. But the point remains: whatever we who deny here-now-ism say about my sentence, so should the possibilist say about modal claims. And so I can't see any more reason to insist that the possibilist appeal only to actual ontology in accounting for modal truths than I can see to insist that Armstrong only appeal to Australian ontology in accounting for my truth.

Anyways, Merricks' reply had loads of interesting stuff in it - these are just my initial thoughts about how best to respond.


Mike Almeida said...

The Lucretian says I have (presently) a purely past-directed property: the property of having once been a child. In 'Truthmaking for Presentists', I argued that what is peculiar about such properties is that an object's having them makes no difference to the intrinsic nature of the object at the time it instantiates it.


I think I'm not sure why the instantiation of having once been a child makes no intrinsic difference to you now. Take any intrinsic property P you currently have. You wouldn't have P were you never a child. So the property of once having been a child seems to make a pretty serious difference to the intrinsic properties you now possess.

Ross Cameron said...

It's not obvious that for any current intrinsic property I have that I wouldn't have had it had I never been a child; had I never been a child, not implausibly, I would have come into existence as an adult (I assume in this context that these worlds are closer than ones in which I simply don't exist) - so I might still have been 6 foot tall, brown-haired, etc.

But in any case, the sense of 'making a difference' I had in mind was more than mere counterfactual dependence. I was thinking that the possibility that I have the same present intrinsic nature without ever having been a child was enough to show that I don't have my present intrinsic nature in virtue of presently instantiating *having been a child*. (Actually, it's not quite that simple: in Truthmaking for Presentists I argue that my 'difference making' claim can't be analysed modally - but hopefully this gives the general idea.)

Mike Almeida said...

I was thinking that the possibility that I have the same present intrinsic nature without ever having been a child was enough to show that I don't have my present intrinsic nature in virtue of presently instantiating *having been a child*

Suppose just moments ago I severed my arm off. I'd want to say that my having done so moments ago makes an important difference to the profile of intrinic properties I now instantiate. It seems clear to me that it does. Among my current intrinsic properties is the property of being one-armed; I did not have that property a moment ago. But on your view, it looks like my having severed my arm off makes no difference to my current set of intrinsic properties. There are worlds in which I came into existence moments ago with one arm, and have all of the other intrinsic properties I now instantiate.

Ross Cameron said...

I agree it makes a causal difference, Mike, but that's not the sense of difference-making I'm interested in. I want to say that the only properties I have are ones such that I have my current intrinsic nature *in virtue of* instantiating those properties - and I don't think causal dependence is sufficient for this in virtue of claim.

Lee Walters said...


I don't know this literature, but I was interested in what you said about worlds and negative existentials and just want to be sure I've understood it correctly.

You say that "The view is that each positive truth has a truthmaker, and that the world is *essentially* composed of all and only these truthmakers."

So the world could not have been composed of different truthmakers. So given some falsehood, P, you think that the modal claim "it could have been that not P" is not a claim about how the world could have been. Rather you think there could have been a different world? And you think this adequately captures our modal discourse?

Lee Walters said...

Oops - I have an erroneous 'not' in my previous comment.

Ross Cameron said...

Lee, absolutely! In slogan form: not every de dicto way that things could have been is a de re way the world might have been. In Lewisian terms: not every possible world is a counterpart of the actual world.

I think there's independent reason to hold this - and then I'm just extending this thought to allow for a solution to negative existentials.

I don't think this does any damage to our modal discourse, etc, since I think all that's required is that there are these worlds, not that they be counterparts of our world. I'd be interested in any reason to think the contrary.

mrogblog said...

You say - not every world is a counterpart of the actual world. On your view, though, isn't this stronger claim true: only the actual world is a counterpart of the actual world? If not, I must be missing something obvious...

In similar vein, I remember Stephen Kearns arguing at an Oxford graduate seminar that the laws of nature are just those truths that are essentially true of the world. Seems to work nicely.

Of course, the difference is that he allowed some degree of variance of the way our world is, while still remaining our world - you're suggesting that you can't change our world at all without making it a different world. Perhaps, if we're Lewisians, we could just say that different counterpart relations are to be invoked in the two cases?

Ross Cameron said...

Mroblog: yes, the claim I think we have independent justification for is that not every world is a counterpart of ours. My thought is that once we're already committed to that, there shouldn't be any objection to extending that to the claim I need: that the only counterparts of our world are indiscernible worlds (so if there are no distinct indiscernible worlds, our world has no counterpart other than itself).

and yes, if you're Lewisian you can have multiple counterpart relations and say I'm just invoking an especially strict one. As long as you'll grant me that it's the appropriate CP relation to invoke in this context, I'm quite happy with that.

Anonymous said...

The human scale Truth Makers have always been the Realized Saints, Yogis, Mystics and Sages.

IT (the Truth) has never come from any where else. That is why such rare beings were revered in times prior to the modern era (and still are in many parts of the world).

Please find an introduction to the only Truth Maker that has ever appeared in the Western world.

All the rest of the "great minds" have been crawling around in Platos Cave trying to either figure it all out or find a way out---but the cave, or rather the klik-klak chequer-board, goes on forever in all directions.