Debunking Arguments

Debunking Arguments

We encounter some atoms arranged treewise and some atoms arranged dogwise, and we naturally take there to be a dog and a tree. But there are different ways we might have carved up such a situation into objects. Instead of taking there to be a tree there, we might instead have taken there to be a trog—a partly furry, partly wooden object composed of the dog and the tree-trunk.
Why, though, do we naturally take there to trees rather than trogs? Plausibly, this is largely the result of various biological and cultural contingencies. If so, then there arguably is little reason to expect that our beliefs about which objects there are would be even approximately correct. This realization, in turn, is meant to debunk our beliefs about which objects there are:

(DK1)There is no explanatory connection between how we believe the world to be divided up into objects the how the world actually is divided up into objects.
(DK2)If so, then it would be a coincidence if our object beliefs turned out to be correct.
(DK3)If it would be a coincidence if our object beliefs turned out to be correct, then we shouldn’t believe that there are trees.
(DK4)So, we shouldn’t believe that there are trees.

The idea behind DK1 is that we are inclined to believe in trees rather than trogs largely because prevailing conventions in the communities we were born into generally prohibit treating some things as the parts of a single object unless they are connected or in some other way unified. These conventions themselves likely trace back to an innate tendency to perceive only certain arrays of qualities as being borne by a single object and its being adaptive for creatures like us to so perceive the world. But the facts about which distributions of atoms do compose something, or about which arrays of qualities truly are borne by a single object, have no role to play in explaining why this is adaptive. Thus, it would seem that we divide up the world into objects the way that we do for reasons having nothing at all to do with how the world actually is divided up.
The idea behind DK2 is that if there truly is this sort of disconnect between the object facts and the factors that lead us to our object beliefs, then it could only be a lucky coincidence if those factors led us to beliefs that lined up with the object facts. And the idea behind DK3 is that since we have no rational grounds for believing that we got lucky, we shouldn’t believe that we did, in which case we should suspend our beliefs about which objects there are and, in particular, our belief that there are trees.[38]
Such debunking arguments fall short of establishing that eliminativism is true or that conservatism is false. But, if successful, they do lend powerful support to eliminativism, by effectively neutralizing any reasons we might take ourselves to have for accepting conservatism or for wanting to resist the arguments for eliminativism.[39]
The arguments also lend indirect support to permissivism, insofar as permissivists are well positioned to deny DK2. By permissivist lights, having accurate beliefs about which kinds of objects there are is a trivial accomplishment (not a coincidence), since there are objects answering to virtually every way that we might have perceptually and conceptually divided up a situation into objects. The ordinary and extraordinary objects are all already out there waiting to be noticed; all that our conventions do is determine which ones are selected for attention.[40]
Deflationists also seem well positioned to deny DK2. Relativists will say that, while we could easily have divided up the world differently, we could not easily had divided up the world incorrectly. For had we divided the world into trogs rather than trees, we would then have had a different conceptual scheme, and we would have correctly believed that trogs exist-relative-to-that-scheme. Quantifier variantists will say that, had we divided the world into trogs but not trees, we would then have correctly believed that trogs exist*.[41]
Alternatively, one might try to resist DK1 by identifying an explanatory connection between the way the world is divided up and our beliefs about how it is divided up. For instance, one might say that we have the object beliefs that we do as a result of intelligent design: God, wanting us to have largely accurate beliefs, arranged for us to have experiences that represent trees and not trogs. Or one might take a rationalist line, according to which, through some capacity for rational insight, we intellectually apprehend relevant facts about which objects together compose something. Or one might opt for an anti-realist line and insist that there is a mind-to-world explanatory connection: object beliefs determine the object facts and are therefore an excellent guide to which kinds exist.[42]

2.7 Causal Overdetermination

Overdetermination arguments aim to establish that ordinary objects of various kinds do not exist, by way of showing that, if they exist, they don’t do any distinctive causal work. Here is one such argument:

(OD1)Every event caused by a baseball is caused by atoms arranged baseballwise.
(OD2)No event caused by atoms arranged baseballwise is caused by a baseball.
(OD3)So, no events are caused by baseballs.
(OD4)If no events are caused by baseballs, then baseballs do not exist.
(OD5)So, baseballs do not exist.[43]

For the purposes of this argument, ‘atoms’ may be understood as a placeholder for whichever microscopic objects or stuff feature in the best microphysical explanations of observable reality. These may turn out to be the composite atoms of chemistry, they may be mereological simples, or they may even be a nonparticulate “quantum froth”.
One could resist OD1 by maintaining that some things that are caused by baseballs are not also caused by their atoms. On one way of developing this line of response, baseballs “trump” their atoms: atoms arranged baseballwise can’t collectively cause anything to happen so long as they’re parts of the baseball. On another, there is a division of causal labor: baseballs cause events involving macroscopic items like the shattering of windows, while their atoms cause events involving microscopic items like the scatterings of atoms arranged windowwise. Both strategies, however, look to be in tension with the plausible claim that there is a complete causal explanation for every physical event wholly in terms of microphysical items. Moreover, this line of response would seem to require that baseballs have emergent properties—causally efficacious properties that cannot be accounted for in terms of the properties of their atomic parts—which seems implausible.[44]
OD2 can be motivated as follows:

(OD6)If an event is caused by a baseball and by atoms arranged baseballwise, then the event is overdetermined by the baseball and atoms arranged baseballwise.
(OD7)No event is overdetermined by a baseball and atoms arranged baseballwise.
(OD2)So, no event caused by atoms arranged baseballwise is caused by a baseball.

Let us say that an event e is overdetermined by o1 and o2 just in case:

(i)o1 causes e,
(ii)o2 causes e,
(iii)o1 is not causally relevant to o2’s causing e,
(iv)o2 is not causally relevant to o1’s causing e, and
(v)o1≠ o2.

Let’s just take this as a stipulation about how ‘overdetermined’ is to be understood in the argument, thus preempting nebulous debates about whether satisfying these five conditions suffices for “real” or “genuine” overdetermination. To say that o1 is causally relevant to o2’s causing e is to say that o1 enters into the explanation of how o2 causes e to occur in one of the following ways: by causing o2 to cause e, by being caused by o2 to cause e, by jointly causing e together with o2, or—where o2 is a plurality of objects—by being one of them.[45]
Can OD6 be resisted? The idea would have to be that, although some events are caused both by atoms and by baseballs composed of those atoms, those events are not overdetermined (in the indicated sense). But if they are not overdetermined, then which of the five conditions for overdetermination do the baseball and the atoms fail to meet? This line of response takes for granted that (i) and (ii) are satisfied. And it is extremely plausible that (iii) and (iv) would be satisfied as well. However it is that baseballs “get in on the action”, it isn’t by entering into the causal explanation of how the atoms manage to cause things. Baseballs don’t cause their atoms to shatter windows, nor do their atoms cause them to shatter windows. So those who would deny OD6 will need to deny that condition (v) is satisfied, by taking the baseball to be identical to the atoms. See §3.3 below for discussion of the thesis that objects are identical to their various parts.
Why accept OD7? In certain cases, overdetermination strikes us as an overt violation of Ockham’s Razor: do not multiply entities beyond necessity. But given the intimate connection between baseballs and their atoms, it is natural to feel that even if these do count as cases of overdetermination (in the indicated sense), this isn’t an especially objectionable sort of overdetermination. One may then attempt to resist OD7 by articulating a further condition which distinguishes problematic from unproblematic cases of overdetermination. For instance, one might hold that overdetermination by o1 and o2 is unproblematic so long as o1 and o2 aren’t entirely independent.[46]
Even supposing, however, that the line between objectionable and unobjectionable sorts of overdetermination can be drawn in some satisfactory way, there would still be pressure to accept OD7. We should accept that something other than the atoms shatters the window only if we have good reason to believe in this something. But there is no explanatory need to posit baseballs, since there is a complete causal explanation for all of the relevant events wholly in terms of the activities of the atoms. And the debunking arguments in §2.6 purport the show that our ordinary perceptual reasons for believing in baseballs are no good. So we would seem to have no good reason at all to accept that there are baseballs, in which case we ought to accept OD7.[47]
Premise OD4 can be motivated in much the same way as OD7. If baseballs don’t cause anything to happen, then we have no good reason to believe in them, in which case we should accept OD4. One might also give a more direct defense of OD4 by appealing to the controversial Eleatic Principle (a.k.a. Alexander’s Dictum), according to which everything that exists has causal powers. Together with the plausible assumption that if baseballs don’t cause anything it’s because they can’t cause anything, the Eleatic Principle entails OD4.[48]

2.8 The Problem of the Many

The office appears to contain a single wooden desk. The desk is constituted by a single hunk of wood whose surface forms a sharp boundary with the environment, without even a single cellulose molecule coming loose from the others. Call this hunk of wood ‘Woodrow’. Now consider the object consisting of all of Woodrow’s parts except for a single cellulose molecule, ‘Molly’, making up part of Woodrow’s surface. Call this ever-so-slightly smaller hunk of wood ‘Woodrow-minus’. Because Woodrow-minus is extraordinarily similar to Woodrow, there is considerable pressure to accept that Woodrow-minus is a desk as well. This, in short, is the problem of the many.

(PM1)Woodrow is a desk iff Woodrow-minus is a desk.
(PM2)If so, then it is not the case that there is exactly one desk in the office.
(PM3)There is exactly one desk in the office.

PM1 and PM2 straightforwardly entail that PM3 is false; one of these claims has to go.[49]
PM1 is plausible. Woodrow-minus seems to have everything that it takes to be a desk: it looks like a desk, it’s shaped like a desk, it’s got a flat writing surface, and so forth. Accordingly, it would be arbitrary to suppose that Woodrow but not Woodrow-minus is a desk. Moreover, if Molly were removed, Woodrow-minus would certainly then be a desk. But since Woodrow-minus doesn’t itself undergo any interesting change when Molly is removed (after all, Molly isn’t even part of Woodrow-minus), it stands to reason that Woodrow-minus must likewise be a desk even while Molly is attached to it.
One might deny PM1 on the grounds that being a desk is a “maximal” property, that is, a property of an object that cannot be shared by large parts of that object. Since Woodrow is a desk, and since Woodrow-minus is a large part of Woodrow, Woodrow-minus is not a desk.[50]
But this style of response can be rendered unavailable by introducing an element of vagueness into our story. Suppose now that Molly has begun to come loose from the other molecules, in such a way that it is naturally described as being a borderline part of the desk in the office. Let Woodrow-plus be the aggregate of cellulose molecules that definitely has Molly as a part. PM1 can then be replaced with PM1′:

(PM1′)Woodrow-plus is a desk iff Woodrow-minus is a desk.

Woodrow-plus and Woodrow-minus each seem to have everything that it takes to be a desk, and neither seems to be a better candidate than the other for being a desk. PM2 would then be replaced with PM2′:

(PM2′)If Woodrow-plus is a desk iff Woodrow-minus is a desk, then: it is not the case that there is exactly one desk in the office.[51]

PM1′ can be resisted by proponents of the supervaluationist strategy sketched in §2.1 above. The vague term ‘desk’ has multiple precisifications, some of which apply to Woodrow-plus, some of which apply to Woodrow-minus, but none of which applies to both. Accordingly, PM1′ is false on some precisifications, and therefore is not true simpliciter.[52]
Constitutional pluralists can deny both PM2 and PM2′. Regarding the original story, they may insist that neither Woodrow nor Woodrow-minus is a desk. Each is a mere hunk of wood, and no mere hunk of wood is a desk. Rather, there is exactly one desk, it is constituted by Woodrow, and while Woodrow-minus would constitute that desk if Molly were removed, as things stand it constitutes nothing at all. Regarding the revised story, pluralists may again say that there is exactly one desk, neither Woodrow-plus nor Woodrow-minus is a desk, and it is simply indeterminate whether it is Woodrow-plus or Woodrow-minus that constitutes that desk. So PM2′ is false: it’s true that each is a desk iff the other is—since neither is a desk—but it doesn’t follow that there’s more than one or fewer than one desk.[53]
Finally, one might deny PM3, either by accepting an eliminative view on which there is no desk in the office or by accepting a permissive view on which there is more than one desk in the office. Proponents of the latter response will end up committed to far more than two desks, however. By parity of reason, there will also be a desk composed of all of the cellulose molecules except Nelly (≠ Molly). Likewise for Ollie. And so on. So there will be at least as many desks as there are cellulose molecules on the surface of the desk.[54]

Debunking Arguments