Upload
raleighmiller
View
217
Download
0
Embed Size (px)
Citation preview
8/9/2019 On Impossible Imaginings
1/15
1
Raleigh MillerGSU, 2008
On Impossible Imaginings1
0. IntroductionAlex Byrne (2007) has argued that, [i]maginability...is no guide to possibility. I will argue
that Byrne's defense of his argument does not succeed. The argument looks like this:
Argument (B)
1. We can imagine impossible P's.2. If we can imagine impossible P's, imaginability is no guide to possibility.3. Conclusion: Imaginability is no guide to possibility.
This conclusion, if true, is relevant to the dispute over whether the mental is different in kind
from the physical. Discourse concerning this question is referred to as the mind-body debate. Dualists
argue that the mental and the physical are ontologically distinct, either by virtue of being different sorts
of substance or by being different properties of physical substances. Many dualists, like Rene
Descartes and David Chalmers have advanced or endorsed so-called conceivability arguments. With
a broad brush, one might say that a prototypical conceivability argument, pertaining to the mind-body
debate, is structured as follows:
Argument (C)
1. It is conceivable that the mind exist without the body or that the body exist without the mind.2. If the mind and the body are conceivably separable, they are possibly separable.3. If the mind and body are possibly separable, the mind is not the body.4. Conclusion: The mind is not the body.
A well known reformulation of, or argument for2, premise one is suggested by David Chalmers, and is
known as the zombie argument.(c.f. Chalmers (online)) Zombies are physical systems identical to our
own bodies (brains and all), but within which no conscious experience occurs. According to the
1 Everything good about this paper, if anything there be, is owed to the generous help of Justin Bernstein, Jodi Geever,
PaulPfeilschiefter, and Ben Sheredos (listed alphabetically).
2 I consider Chalmers assertion regarding zombies a reformulation of premise 1. Others have suggested to me that it is
an argument for premise 1. Nothing rests on this distinction.
8/9/2019 On Impossible Imaginings
2/15
2
dualist, zombies (or some comparable thought experiment that falls under the constraints of premise 1)
are conceivable. Materialists, who argue that the mental is not different in kind from the physical,
insist that premise 4 of (C) is false, and consequently aim to dismantle the zombie argument. The
literature has largely focused upon this dismantling in two ways. First, many have denied that zombies
are conceivable. Second, many have denied that the conceivability of zombies entails their possibility.
Byrne (with others)3
takes the second approach.
The form of conceivability discussed in this paper will be a species of positive conceivability,
which is contrasted with negative conceivability. A proposition, S, is negatively conceivable if it is not
ruled out by any internal inconsistency. Alternatively, S is positively conceivable only if one can
form some sort ofpositive conception of a situation in which S is the case (Chalmers 2002).
Presumably, positive conceivability of S makes a much stronger case for S's metaphysical possibility
than mere negative conceivability. But to form some sort of positive conception of a situation is to
imagine such a situation. If Byrne is right, and S's imaginability cannot guide us towards knowledge of
S's possibility, then a damaging blow has been dealt to the zombie argument, and dualism generally.
Consequently, this paper will concern itself with positive conceivability.
The conclusion of this paper is that Byrne has not made a persuasive case for premise one of
(B). In section I, I will develop Byrne's argument, and I will present three imaginable scenarios that
Byrne takes to be impossible. One suggested scenario is the perception of a visual illusion. In the
remaining two scenarios, non-identical objects are taken to be identical. In section II I will show that
Byrne has not satisfactorily demonstrated that visual illusions are examples of imaginable
impossibilities. In section III I will argue that in cases where non-identical objects are imagined to be
identical, the identity being imagined is not impossible. In section IV I will conclude that we are left
with no good reasons to reject the efficacy of imaginability towards establishing possibility.
3 C.f. Bailey (MS) Bokulich (MS) Barnes (2002), Dietrich (2001), Hill (1997), Yablo (1998) For denials of premise 1,
see Kirk (1999) Kirk (MS), Marcus (2004)
8/9/2019 On Impossible Imaginings
3/15
3
I. ByrneSaul Kripke argues that proper names are rigid designators. (Kripke 1980) A rigid designator is
baptized of a token object (We shall name him Aristotle) and refers to that particular object in all
possible worlds. If X to rigidly designate A, then X refers to the same thing, A, in all worlds in which
A exists, such that the thing designated, A, is identical across possible worlds.4 Another way to say the
same thing is X picks out A in all possible worlds. If Y also refers to A in all possible worlds, then
in all possible worlds, X and Y pick out the same object. From this we can conclude that there is no
world in which X is not identical to Y, or, necessarily X equals Y.5,6
In such a case, it is impossible
that X is not identical to Y. Let a Kripkean impossibility be understood as follows:
A proposition, P, is a Kripkean impossibility if and only if,
(K) P asserts of two rigid designators, X and Y, which pick out the same object, that X is not Y
or, asserts of two rigid designators, X and Y, which pick out different objects, that X is Y.7
As a novel example, one may consider the proposition that Hesperus is not Phosphorus. This
proposition is false in this world, because Hesperus and Phosphorus both refer to the planet Venus.
Furthermore, because Hesperus and Phosphorus are rigid designators, and because they both pick out
Venus in all possible worlds, there is no possible world in which they do not pick out the same object.
4It is hard to briefly summarize this point without saying things that are actually false. For instance, in this case, A is NOT
actually identical across possible worlds. For instance, President Nixon is not identical to failed presidential candidate
Nixon. When I say that the thing designated is identical in all possible worlds, I should be understood as saying that the
thing designated is the same thing in all possible worlds, but even this risks inaccuracy, insofar as if two things are the
same thing (again, a confusing way to word it) they should share all the same properties, and should not differ in the
property of, for instance, whether they won the election. Im grateful to my colleagues for doing their best to help me
tighten this section, and I regret its inadequacy as it currently stands. I hope, and suspect, that whatever nuances have
been glossed over by my account will not prove damaging to the success of this paper.5
We can conclude as much, that is, with the help of an additional premise, which simply defines the necessary operator as
true in all [visible] worlds. That is, if necessarily , for any [visible] world, w, V(, w)=1, or is true is w. 6 I thank Ben Sheredos for pointing to a problem concerning the present account. He and I share the worry that in these
cases (and in many cases involving Kripkean identity) the expression of the identity is vague as to what is being
identified with what. I have said that, if X and Y pick out the same object, then X equals Y. But I have also said, of X
and Y, that they are designators, and that they are distinct designators (for instance Hesperus and Phosphorus). Thus, if
X equals Y is taken to mean that the designator X and the designator Y are identical to one another, this would be
nonsense. It is natural and charitable to assume that when such equivocations are committed, the author can be
understood as meaning that the object, substance, or person referred to by X is identical to the object, substance or
person referred to by Y. When identity claims are being thrown around willy nilly, however, there is a salient risk that
such a misstep may make some implausible claims look attractive, and Ben's concern is worthy of our attention.
7 The concept of a Kripkean impossibility is Byrne's.
8/9/2019 On Impossible Imaginings
4/15
4
Therefore, Hesperus is not Phosphorus is false in allworlds. This is to say that Hesperus is not
Phosphorus is impossible. Byrne asks whether there is any proposition, P, which satisfies (K) and is
imaginable. If such a proposition can be found, then imaginability is not a guide to possibility.
To allay some initial concerns, we may gloss over the distinction between imagining that P and
conceiving that P. Byrne acknowledges that these are different, but we can weakly say that if
something is imaginable, then it is conceivable in some sense. Therefore, that this distinction is
ambiguous will not pose a problem for the structure of Byrne's argument as a whole. If P is imaginable
and impossible, then P is conceivable and impossible. If Byrne's argument goes through, the extent to
which imaginability is a guide to possibility, and a fortiori, the extent to which conceivability is a guide
to possibility, will have been undermined. For the sake of this paper, one may simply suppose that of
any proposition, the extent to which that proposition is imaginable is the extent to which that
proposition is conceivable.
Imagining that P requires more than supposing, or entertaining that P. Byrne writes,
Something extra is needed: a mental image...is sufficientand perhaps it is also necessary. (9) In
order to imagine P, (e.g. that there are tailless kangaroos) we bring to mind an image that satisfies P (a
kangaroo without a tail). Likewise, for some P to be positively conceivable on Chalmers account
requires that one be able to form some sort of positive conception of a situation [, S,] in which [P] is
the case.(Chalmers, quoted above) One might charge that some possibilities (for instance, that
Germany won the Second World War) are not imagined as a mental image; Byrne does away with this
problem. For any P of this latter sort, to positively conceive of it is to bring to mind (or to be able to
bring to mind) an image that one would only ever see if the proposition was true. In the case of the
WWII example, we imagine Hitler waving from the balcony of Buckingham palace, or in the oft cited
case of Nixon losing the election, we can imagine Humphrey giving the state of the union address.
(Byrne 18-9) So, when we imagine P, we form a sensory representation which uniquely corresponds to
a situation in which P is true. Non-sensuous imaginings are reducible to, or expressible in, sensuous
8/9/2019 On Impossible Imaginings
5/15
5
imaginings. Thus, if imaginability is a guide to possibility, nothing impossible should be sensuously
imaginable.
So far, by my estimation, Byrne has said nothing that will give him any trouble. It may be
worth suggesting that Byrne's account of imagination is strange, or that one can think of innumerable
instances of non-sensory imaginings that cant be reduced to sensory imaginings.8 For the present
paper, however, not much depends on whether this account is accurate. If one denies that all
imaginings are sensuous imaginings, one may simply take Byrne to be arguing that one can sensuously
imagine impossibilities. If so, then one can imagine impossibilities.9
For his argument to succeed,
however, Byrne has one further responsibility. He must demonstrate that there is some genuinely
impossible P, which is also sensuously imaginable. Here, I will suggest, Byrne's argument fails.
Ironically, Byrne seems to think that this is the easy part. He presents three candidates for impossible
imaginings.
1. One sees Stephen on the street, and misidentifies him as Vernon. One seems to have perceivedthat Stephen is Vernon. But, Stephen is not Vernon, and is in fact necessarily not Vernon (as
shown by Kripke). One has seemed to perceive something to be true which is necessarily false,
or whose truth is Kripke-impossible, and consequently10
logically impossible.
2. On a wistful summer day, one stares for several minutes at a roaring waterfall. Caught up in themoment, one drops one's camera, and in reaching downward inadvertently focuses on a pile of
rock. Amazingly, the rocks look to be moving. But the rocks are clearly not moving. Oneperceives the rock as both moving and not moving. This is a contradiction, and is clearly
impossible.
3. One goes to an ice sculpture museum. Amidst the art is a table, covered in frost. One seems to8
My colleague Paul Pfeilsheifter, for instance, points out that Byrne seems to argue for this very claim elsewhere (2006).
Paul also asks that we consider imagining that there is a prime number higher than the highest known prime number. I
actually suspect that this latter example could be reduced to a sensuous imagination (I, for instance, imagine a
mathematician concentrating on a very large number and saying Eureka!) At a certain point, however, if one wants todefend Byrnes claim, one will get caught telling implausible, if consistent stories. This is quite unimportant to the
present project however. I grant Byrne his reduction so as to move on to what is more pressing to my criticism.
9 It is not this simple though. The reason Byrne feels compelled to reduce non-sensuous imagination to sensuous
imagination is not hard to see. One could simply say (especially if one were seduced by the visual illusions argument
below) that one's sensuous apparatus is quite faulty, but one's logical apparatus is not. Hence, if indeed Byrne does
show that one can sensuously imagine something impossible, it is open to the dualist to say not all kinds of
imaginability entail possibility. Perhaps nonsensuous imagination, what we may call logical imagination, is required.
Byrne may be vulnerable here, especially if one doubts his account of the reducibility of nonsensuous imagination. This
is not my strategy, however, so I'll let Byrne have his reduction in exchange for his soul main conclusion.10
On Kripkes account, of which I shall not be skeptical in this paper.
8/9/2019 On Impossible Imaginings
6/15
6
perceive that the table is made of ice. But the table is made of wood. One has perceived thatthat table is made out of ice, but that table, in all possible worlds, is made of wood. A table
made of ice, in any possible world, would be a different table. That that table is made of iceis impossible, but one has seemed to perceive as much.
Byrne thinks that these do the trick:
...given the received view about the close kinship between perception and imagination, thissupports the intuitive claim that one can sensuously imagine Kripkean impossibilities, even
in the face of the relevant empirical facts. (Byrne 16)
And further,
Given the examples in the previous two paragraphs, and the received view of the kinship
between perception and imagination, there is no evident reason to deny that one can sensuouslyimagine Kripkean impossibilities... (Byrne 17)
Surely these (1, 2, and 3) are familiar situations. We cannot deny that they, or situations like
them, occur regularly. But is the content of one's imagination, in such situations, impossible? In the
remaining discussion I will suggest that they are not. I will argue that, in these cases, Byrne has
misidentified the content of our imaginings, and that the actual content of our imaginings is not
impossible. First I will consider the second example. This case purports to be one of logical necessity;
that is to say, one has sensuously perceived a contradiction to be true. In section II, I will argue that
one has not, in the case of a waterfall illusion or any similar illusion, sensuously perceived
contradictory propositions, and that we have no good reason to think one is sensuously imagining a
contradiction to be true. Following this, I will consider the first and third cases. These cases purport to
be cases ofa posteriori necessity,11
and rely on the assumption that Kripke's account of rigid
designation and necessity is correct. I will not challenge this assumption. I will argue, in section III,
that in these cases the tokens being identified are not rigid designators, and thus their identification (or
non-identification) is not necessary. There are, on Kripke's account, two ways in which This table is
made of ice or That guy is Vernon can be understood. One of them treats this table and that
11A proposition is a posteriori necessary if it is true in all possible worlds but discoverable empirically. The correlative
concept, and that which Byrne thinks he has identified in the contents of various imaginings, is a posteriori
impossibility. A proposition is a posteriori impossible if it is false in all possible worlds, and consequently
impossible, but its impossibility is discoverable empirically.
8/9/2019 On Impossible Imaginings
7/15
7
guy as rigid designators, and one does not. I will suggest that the imaginings in cases 1 and 3 are of
the second sort, and as such they do not pose a problem to imaginability arguments in the way that
Byrne thinks they do. That is to say, they are not impossible according to (K).
II.Visual Illusions
Consider the waterfall illusion. In a well known visual trick, one looks at a waterfall for long
enough, and then looks at a pile of rocks. The rocks will look as if they are moving. Byrne needs to
demonstrate that one can sensuously imagine an impossibility. One thing, which is certainly
impossible, is a logical contradiction, such as p and ~p. He takes the present case to be just such a
contradiction.
There are familiar examples of perceptual experience that are apparently of impossibilities. Inthe waterfall illusion, the rocks look both to be moving and not moving. (Byrne (2007) 16,
Byrne's emphasis removed, my emphasis added)
But we should be careful. In cases like this, the mode of apparently contradictory representations is
vitally important. There is, after all, nothing contradictory about Bill Richardson's beliefthat he is not
a presidential nominee, and his desire that he is a presidential nominee. These representative modes
carry with them varying conditions of satisfaction. Contradictory propositions can be attributable to a
coherent (that is, logically consistent) state of affairs as long as they are represented according to
modes that do not have the same conditions of satisfaction. According to Byrne, the rocks look to be
moving and look to be not moving. If this assertion is correct, then we indeed have a contradiction on
our hands. For something to look as if P requires that it look the way it would look if P.
Consequently, if something looks as if P, it cannot also look as if not P.12
12 We can rule out cases in which some X would look the way it does whether P or not P is the case. For instance, the gym
bag has a cat sleeping inside. If there were no cat sleeping inside, it would look the same. Therefore, the way the bag
would look given P and the way the bag would look given ~P are the same. This need not be a concern, for in such a
situation we would not say the bag looks as if a cat is sleeping inside, because we know the bag would look the exact
same if the cat were not sleeping inside. We do not say the water looks as if it's 50 degrees, though we may say it feels
as if it were 50 degrees. Though we believe that the water might look the same if it were twenty degrees, we assume it
would feel differently. For an extended discussion of this, and also one of my favorite philosophical works, see Dretske,
Seeing and Knowing. I borrow the gym bag example from my friend PaulPfeilschiefter. He may or may not have
borrowed it from Byrne.
8/9/2019 On Impossible Imaginings
8/15
8
But here, Byrne is wrong. In a situation such as the waterfall illusion, it is false that the rocks
look as if they are not moving. They look as if they are moving. That is the illusion, after all. What
may be true is that the subject believes thatthe rocks are not moving. In fact, this is almost certain to
be the case. Thus, one takes two propositions to be true. 1) The rocks look as if they are moving. 2)
The rocks are not moving. But this is hardly a contradiction, and it is hardly impossible!13 Byrne
writes as though every visual illusion supports his case. I maintain, however, that with any visual
illusion that one could produce, a similar distinction could be drawn, and the apparent contradiction
would be dissolved. The lines behind the squares look to be non parallel, but they are parallel. The
lines in Guitar Hero look to be moving, but they are not moving. In each case, contradictory
propositional contents are only satisfied if they are assigned to distinct modes of representation, once
this clarification has been accomplished, the apparent contradiction will vanish.
Byrne does mention one category of visual illusion which may be better served to demonstrate
his point: M.C. Escher's impossible objects. For instance, a man sits on a bench with what looks like a
box frame. (See Appendix). But as one looks closer, one realizes what the man holds is quite strange.
The corners of the frame cross one another in ways that no actual frame could. The frame is
impossible. And yet, we are looking right at it. We sensuously perceive it, which means that if asked
to, we could sensuously imagine it. Might this show that we can sensuously imagine impossible
things? I have two suggestions against such a claim.
First, if we look at the entire frame, we don't actually see the object. This is part of the
enjoyable strangeness in the phenomenology of looking at such paintings. We have Gestalt tendencies
to make the frame a coherent box when looked as a whole. It is only when we look at particular parts
of the box that we can work out what exactly is so strange about it. We look at such images in a
piecemeal fashion: first at this corner, then at this other corner, until we discover what is incoherent
13A colleague has suggested that exclamation points are inappropriate to philosophy papers. I respectfully disagree. I think
philosophers should be exclamatory more often.
8/9/2019 On Impossible Imaginings
9/15
8/9/2019 On Impossible Imaginings
10/15
10
very poor footing.
So much for visual illusions. What, then, ofa posteriori necessities?
III.Kripkean IdentiesSaul Kripke argues that proper names are rigid designators. A rigid designator picks out an
object in all possible worlds. So if two rigid designators pick out the same object, they do so in all
possible worlds. Another way to say this is that they are necessarily identical. In this sense, it is
impossible that Bob Dylan is not Robert Zimmerman, or that Hesperus is not Phosphorus. The
introduction of the rigid designator was a response to the received view of reference, endorsed by Frege
and Russell, that names are definite descriptions. If a proper name is a definite description, then the
name picks out the unique object that satisfies all or most of a unique set of properties. This was a
monumental step in the philosophy of reference, because it solved a serious problem that the Frege-
Russell picture faced. If Aristotle is a definite description, then Aristotle refers to Plato's greatest
student AND the teacher of Alexander the Great AND the author of theNichomachean Ethics
AND...etc. But Aristotle could not have written theNichomachean Ethics. By this I mean, there is a
possible world in which Aristotle did not write theNichomachean Ethics, but wrote a steamy romance
novel instead. In this sense, most of the properties of Aristotle could have not been true of Aristotle,
and yet Aristotle would still be Aristotle. Kripke concludes, Aristotle cannot stand in for a definite
description; it must designate the same person in all worlds, even worlds in which Aristotle had not
written theNichomachean Ethics, and worlds where Aristotle had not become a philosopher at all.
kin, so if we can seem to perceive contradictions, as we do in cases of visual illusion, then we can imagine them. He
makes some comments to this effect in his paper. His comments, however, leave one unsatisfied as to the nature of this
kinship. What's more, I think we have to acknowledge a distinction between thinking one is imagining, and actuallyimagining, though I feel severely under-equipped to rigorously define such a distinction. Consider the first time an
undergraduate is asked if they can imagine a round square. In my experience, a great many of them say yes! They must
be coaxed: We're not talking about changing the meaning of the words, we're talking about all of the properties that
make something a circle, and all of the properties that make something a square. Can you imagine a single object
having all of those properties? Finally they say no.
Accordingly, the argument of this section should be taken as a meek categorical claim, if there is such a thing. In any
case where the content of an imagination seems to be impossible, it is probably the case that one is failing to actually
imagine what has been presented. Maybe this will be doubted, but I don't think it will be doubted by materialists, since
they rely on a similar argument structure with respect to the Zombies. (You think you're imagining zombies; you're not
actually imagining zombies.)
8/9/2019 On Impossible Imaginings
11/15
11
But Kripke's theory does not purport to characterize all references. After Kripke, we need not
assume that all referential words and phrases are rigid designators. Indeed, we must allow that many
are not. For instance, the teacher of Alexander the Great refers to Aristotle in this world, but in many
possible worlds it refers to a different person entirely. Consider a world, similar to ours, in which Fred
was a philosopher of repute, and a contemporary of Aristotle's. In such a world, the proposition that
Fred was the teacher of Alexander the Great is false, but it is not impossible.15
In some possible
world, we suppose, that proposition would be true. Identities between definite descriptions, or between
rigid designators and definite descriptions, are contingent, not necessary.
But what about that guy is Vernon? Or this table is made of ice? These sentences employ
demonstratives as referential phrases: that guy and this table. Are these demonstratives rigid
designators? If so, then it appears that by identifying that guy with Vernon, one has imagined that
two designators, which necessarily refer to separate things, refer to the same thing, and this is
impossible.16
This, according to Byrne, is what has happened. Consider the following:
Suppose one is familiar with the daughter of Mr. and Mrs. Truman. In fact, she and Queen
Elizabeth look remarkably alike. Seeing the Queen on the street, one misidentifies her (by sight)
as the daughter of Mr. and Mrs. Truman. One sees her as the Trumans daughter; I saw the
Trumans daughter on the street and recognized her immediately, one might say. What one
seemed to perceive, namely that that woman is the Trumans daughter, is impossible. (Byrne
17; Byrne's emphasis)
Here Byrne says that the identity between that woman and the Truman's daughter is, if true,
necessarily true, and if false, necessarily false.17
But this is only true if the demonstrative that
15And, in some sense, insofar as we can imagine a world in which this is possible, it is possible in our world. Possibly
possibly P entails possibly P in modal system S4 (requiring transitivity of the is visible or R relation between possibl e
worlds.) S4 is an unproblematic extension of the minimal system K, and insofar as the concept of necessity operative hereis at all robust, it ought to pack transitivity into R. I am hesitant to reiterate the first sentence of this footnote with a tone of
certainty, however, as the involvement of a rigid designator Fred may complicate the issue. I suspect not, however, as a
rigid designator picks out the same object in all worlds in which the object exists. As such, possibly possibly P probably
entails possibly P in this case, and gives us no cause to worry about Fred as a rigid designator. However, nothing rests on
this, and to avoid complication we may simply discuss imagining a world in which Fred exists and is such-and-such.16
Im noticing a vagueness in the way this is written. Regrettably,Im noticing it with very little time left before the paper
is due, and so I cannot fix it now. Future versions of this work, if any there be, need to work this sentence out more
precisely. This footnote is more or less a note to self.17
I think Byrne is giving himself some undue trouble here, and I have tried to make his argument stronger by speaking of
Stephen and Vernon. On Kripke's account, only an identification between rigid designators is necessary. Identities between
8/9/2019 On Impossible Imaginings
12/15
12
woman is a rigid designator. We must investigate whether such is the case.
Before we can evaluate whether an identity is necessary, we must know when we are facing a
rigid designator and when we are not. Grammar will not help. We cannot say that any demonstrative
is or is not a rigid designator. We cannot even say this about proper names! As Kripke points out,
Jack the Ripper is a definite description; it refers to whichever individual committed certain
murderous acts. Likewise, I suggest, a demonstrative that object may be a definite description or a
rigid designator, depending on how it is used. Rather than trying to sharply delineate which words or
phrases shall count as rigid designators and which shall count as definite descriptions, these labels are
best understood functionally. A referential phrase is a rigid designator only if it fixes trans-world
identity. A referential phrase is a definite description if it refers to whatever object satisfies a set of
properties. And this is the best we can do.
Kripke himself suggests that not all demonstratives are rigid designators. Consider the
following:
Of course, it is only a contingent truth (not true in every other possible world) that the star seenover there in the evening is the star seen over there in the morning , because there are possible
worlds in which Phosphorus was not visible in the morning. But that contingent truth shouldn'tbe identified with the statement that Hesperus is Phosphorus. It could only be so identified if
you thought that it was a necessary truth that Hesperus is visible over there in the evening...But
[that is not] a necessary truth...These are contingent marks by which we identify a certain planetand give it a name. (Kripke 105; my emphasis)
This passage should reorient us in our discussion. Let us remember what is at stake: the
question is whether That guy is Vernon expresses a proposition that, if true, is necessarily true, and if
false, is necessarily false. It would only be such a proposition if That guy and Vernon are both
definite descriptions are contingent. Identities between rigid designators and definite descriptions, are contingent. Byrnesuggestion that that woman is the Truman's daughter is, if true, necessarily true, assumes that both that woman and the
Trumans' daughterare rigid designators, and neither case seems obvious. Instead, That guy is Stephen presents at least
one reference that is quite certainly a rigid designator, leaving us to focus on that guy. For this reason I consider myself
to be strengthening Byrne's argument by focusing on That guy is Stephen. It has been suggested that I contradict myself
here. I said above that not all proper names are rigid designators, so why is Vernon taken to be obviously a rigid designator?
For instance, Jack the Ripper is understood as a definite description. This should not be worrying. I am here assuming that
Kripkes account is accurate. Kripkes own account argues that we should understand Jack the Ripper as a definite
description. However, this is clearly a strange and degenerate case, and is opposed to prototypical proper names, which
Kripke argues are rigid designators. I hope to have given no reason that Vernon should be considered anything but a
prototypical proper name, and as such it may be treated as an unproblematic rigid designator.
8/9/2019 On Impossible Imaginings
13/15
13
rigid designators. But what does that guy refer to? A fixed individual with trans-world identity? I
think not. That guy refers to a token object in the world with a set of relevant properties, namely the
property of occupying a particular place in space-time, and perhaps having certain other properties that
we would use to identify Vernon, such as a particular height, a particular hair style, a particular voice,
etc. After all, necessary identity goes both ways, so to treat that guy as a rigid designator is to
suggest that if that guy wasn't Vernon, then he wouldn't be that guy. This seems quite confused.
I submit that that guy functions as a definite description (and not as a rigid designator) in the
case that Byrne describes.18
To reiterate Kripke, that guy could only be...identified [as a rigid
designator] if you thought it was a necessary truth that Vernon occupied that place in space-time. But
surely we do not think so, because if Vernon does not occupy that space he will still be Vernon, just as
Aristotle would still be Aristotle even if he never studied philosophy.
So, Jill sees Stephen on the street, and says that guy is Vernon. Jill has not identified two
rigid designators, as she would have if she exclaimed Stephen is Vernon! Jill has employed that
guy as a definite description, and is wrongly asserting that the person meeting that description is
Vernon. The identity she proclaims is false, but possible. Indeed, there is a possible world in which
Vernon did satisfy all the properties that uniquely individuate that guy. In this case, no one has
imagined anything impossible.
So what of the table? Byrne writes of our ice-table:
Similarly, suppose sees a certain table (in fact made of wood, but covered with frost), at an ice
sculpture exhibition. One takes it to be made of ice: I looked at the table and clearly saw it was
made of ice, one might say. What one seemed to perceive, namely that that table is made of
ice, is impossible. (2007, 17, Byrnes emphasis)
The consideration here will be largely the same. Again, there are two ways to understand the
phrase that table. The mere fact that that table is a demonstrative does not tell us all we need to
know. We must inquire as to whether the demonstrative is establishing trans-world identity. But
18This sentence was rewritten thanks to a comment by Ben Sheredos. The way it appears here is word-for-word the rewrite
that Mr. Sheredos recommended. As such, he deserves a sort of informal citation.
8/9/2019 On Impossible Imaginings
14/15
14
surely it can't be! Any world in which an ice-table occupies the exact same space and looks the exact
same as the wooden table does in this world is a world in which a different table occupies that space.
The only intelligible way to interpret that table is made of ice is to understand that table as a
definite description. It designates a set of properties (location in space-time, looking a certain way,
etc.) and in any possible world, whatever table satisfies those properties is that table. Thus imagining
that that table is made of ice is only to imagine a world in which an ice table satisfies those
properties. The speaker in this case has not imagined anything impossible.
IV.ConclusionAlex Byrne's argument may well be sound. I do not rule out that there is such a thing as an
imaginable impossibility, but I can't think of one. Byrne thinks he has; by my estimation he has not.
All of the examples of imaginable impossibilities that have been presented are either examples of a)
confusing the content of an imagined state of affairs (as in the case of visual illusions) or b) mistaking
definite descriptions for rigid designators, and consequently taking propositions to be necessary (and
thus, if false, impossible) when they are contingent (if false, still possible). As far as this paper is
concerned, it remains to be seen whether imaginability arguments may successfully figure in possibility
claims. Two routes seem open (if they have not yet been travelled) towards closing this question: a)
someone may present an example of an imaginable impossibility that does not fall to one of these
errors, or else b) we might be given an a priori reason to suppose that nothing impossible is
imaginable.
Perhaps the Zombie argument is already dead. Perhaps not. If not, Byrne has not contributed to
its downfall.
References
Bailey, Andrew R. (MS). The unsoundness of arguments from conceivability. Accessible here:http://www.uoguelph.ca/~abailey/papers/TheUnsoundnessofArgumentsfromConceivability.pdf
Barnes, Gerald W. (2002). Conceivability, explanation, and defeat.Philosophical Studies 108
8/9/2019 On Impossible Imaginings
15/15
15
(3):327-338.Bokulich, Peter (MS). Putting zombies to rest: The role of dynamics in reduction. Accessible here:
http://people.bu.edu/pbokulic/papers/zombie.pdf
Byrne, Alex. (2006) "Color and the Mind-Body ProblemDialectica 60: 223-44 (2006)
Byrne, Alex. (2007) Imaginability and Possibility. (2007) Forthcoming in Philosophical
Perspectives.
Chalmers, David. (2002.)Does conceivability entail possibility?
Conceivability and Possibility
,T. S. Gendler and J. Hawthorne. Oxford: Oxford University Press.
Chalmers, David (Online) Mind and Modality. Accessible here: http://consc.net/papers/mm.html
Dietrich, Eric (1998). It only seems as if zombies are logically possible, or how consciousness hides
The truth of materialism: A critical review of The Conscious Mind.Minds and Machines 8 (3).Hill, Christopher S. (1997). Imaginability, conceivability, possibility, and the mind-body problem. Philosophical Studies 87 (1):61-85.
Kirk, Robert E. (1999). Why there couldn't be zombies. Proceedings of the Aristotelian Society
Supplement73:1-16.Kirk, Robert E. (forthcoming). The inconceivability of zombies.Philosophical Studies.
Marcus, Eric (2004). Why zombies are inconceivable.Australasian Journal of Philosophy 82
(3):477-90.
Kripke, Saul. (1980) Naming and Necessity. Harvard University Press. Cambridge University.Yablo, Stephen (1998). Textbook Kripkeanism and the open texture of language.Philosophical
Quarterly 81 (1):98-122.
Appendix
M.C. Hammer Escher. Main with Cuboid (1958)