Thursday, February 25, 2010

Channeling Gaunilon



Via Bill Vallicella. My take on this -- to live up to the blogosphere's tradition of commenting on things you don't fully understand -- is that it's not clear to me why the fact that we can imagine something being true of A but not of B entails that A and B cannot be identical. Take someone who thinks the evening star and the morning star are two different entities rather than the same thing (namely, the planet Venus). That person could then make claims that are true of the evening star which are not (so he thinks) true of the morning star. "The evening star changed color or blew up" or whatever, "but the morning star remains the same as it always has." In other words, the fact that you can imagine something applying to the one without applying to the other could mean nothing more than that you've misidentified one thing as two. However, this may not apply to Plantinga's argument, since the evening/morning star is an object, and the individual is a subject; and it is precisely as subject that the apparent distinction between it and the body arises.

It looks to me that this modal argument shares a similar intuition with the Ontological Argument: if we can imagine X, then that imagining shows the actual possibility of X. As such, it seems to be subject to the common objection to the Ontological Argument: just because I can imagine X, it doesn't mean that X is actual, and X's actuality is necessary in order for the argument to hold. The counter-response in both cases is that the case under question has a particular quality such that such an imagining does entail its actuality. I tend to agree with Bertrand Russell, that Ontological Arguments are easily dismissed, but it's much harder to explain exactly what's wrong with them. Since Plantinga is one of the most prestigious contemporary defenders of the Ontological Argument, I suspect he might have a better grasp on this than I do.

(cross-posted at Agent Intellect)

Discuss this post at the Quodlibeta Forum

19 comments:

Humphrey said...

Hullo there.

Maybe you can help. Here is where I go wrong with these types of arguments. First off:

"just because I can imagine X, it doesn't mean that X is actual, and X's actuality is necessary in order for the argument to hold."

Yes. That's the objection which immediately screams back at me. I can imagine any number of silly things, but just because I can imagine them doesn't entail they exist.

"The counter-response in both cases is that the case under question has a particular quality such that such an imagining does entail its actuality."

I don't see how that works with Alvin Plantigna not being a material person because he can imagine himself not being a material person. Does not compute (which is probably why I work in sales; not philosophy)

Matko said...

However, this may not apply to Plantinga's argument, since the evening/morning star is an object, and the individual is a subject; and it is precisely as subject that the apparent distinction between it and the body arises.

I strongly disagree. Plantinga's argument is fallacious, and he doesn't present anything new; he just repeats Decartes's argument from detachment and then couples it with modal considerations, mentioning later on Lebniz's law.

The evening star/morning star distinction is the paradigmatic example Frege used to explain his two-tiered theory of meaning. According to Frege, there are two levels of linguistic meaning: meaning and reference (In the original article, Frege calls them Sinn and Bedeutung; the various english translations of Frege's terms have a long tradition of inconsistency.) The referent is the object to whom a proper name refers, and the meaning is the way the proper name's referent is shown to us; its mode of appearance, so to speak. Frege's reasons for such a theory and its details are more pertinent for philosophy of language then for philosophy of mind, so it's superfluous to go into detail.

Now what is relevant for this discussion is that we have to be aware of the distinction between what a thing is and how it is presented to us. Plantinga confuses appearance of an object with how an object actually is, and an object's appearance doesn't always correspond to how an object is in reality.

Another crucial thing is when intensional mental verbs like "imagine" or "believe" are used in an argument like Plantinga's. Intensional states, to which such verbs refer, always have representational content; they're always about something external to them. But that representational content is aspectual – an object can be represented under various aspects that do not necessarily correctly represent the object in question. In such cases, Leibniz's law of identity is inapplicable.

What more can be said? When it comes to formulating a valid ontological argument, or showing that divine attributes are logically compatible with evil's existence, or that theism is a properly basic belief, or that evolution is incompatible with metaphysical naturalism, Plantinga is a philosophical genius, but here, Plantinga was at his worst.

Maolsheachlann said...

I've seen this video before, and I don't "get" it/agree with it for the same reason as the rest of you (though I would be far less adept at putting it).

But I watched it again anyway, because Plantinga is such an avuncular and affable fellow, I just enjoy listening to him!

I get the impression, from watching this and listening to the Dennett debate, that sometimes he likes to make the most audacious arguments out of a kind of impishness.

PerplexedSeeker said...

I'm personally very wary of this kind of argument too. Certainly something isn't possible just because it's imaginable, but what I wonder is if something is impossible because we can't imagine it?

The problem I have with the common argument that mental events are simply a different "mode of access" to the same underlying brain state available to neuroscience(which I guess is where the meaning/referent analogy comes into play) is that in the case of feeling, emotion etc., is that it's precisely the appearance that we're interested in. Specifically, why do some mechanical interactions have an appearance at all, when there's nothing there than could give rise to it? And if mental mechanisms have intrinsic conscious aspects, why don't other things? I don't see how this implication can avoid either some kind of elimination or panpsychism.

I'm not a Cartesian dualist, (I'm fascinated by idealism but I'm still studying the matter and haven't yet reached a final conclusion) but you still have the problem that conscious experience simply isn't necessary on a physicalist account of the mind. Everything which involves it could easily be done without it. Mental content is left dangling impotently from the brain.

Andrew said...

There are a couple problems with your objection regarding the morning/evening star. If the MS=ES, then whatever is true of the MS is true of the ES (after all there is only ONE thing there)!

SO, if it turned out that there was something true (and not just something we *thought* was true) of MS that was NOT true of ES, then ~(MS=ES).
I would say that you really can't imagine ES and MS being different. What you can imagine is that there is something very much like ES only that it is not-ES, being distinct from MS. To imagine one thing being distinct from itself is impossible, all you are doing is imagining something very similar A as being distinct from A. In short, I do not think we really can imagine the MS not being the ES, all we can do is imagine the "MS" as being distinct from the "ES" (sorry if this presuppose a great deal of phil. of language).

So, if it is really true that it is *possible* that A is not identical to B, then it is actual that A is not identical to B. The problem for Plantinga will be with trying to explain that it is possible for A to be distinct from B, and not just *think/imagine* something really similar to A as being distinct from B (analogous to thinking that something really similar to the MS is distinct from the ES). Ultimately, I think there are good reasons to think it is possible that the mind is not identical to the brain, but this isn't for reasons Al gives in the video above, but due to dependence relations.
I suggest reading E.J. Lowe's "Form without Matter" article, I think he gives a more sophisticated argument for why it is possible that the mind and brain are not identical.

Agellius said...

What he doesn't answer sufficiently, and what the interviewer doesn't seem to ask in a sufficiently clear manner, is how we know that the statement "it's possible that A can exist without B" is *true*.

Agellius said...

It just occurred to me what he might mean, and I hope someone can correct me if I'm missing something:

Maybe what he's saying is that it's *conceivable* that I could exist without my body. But it's not conceivable that my body could exist without my body, because such a thing would be a contradiction.

Therefore you can make a statement about me ("A") that you can't make about my body ("B"): It's conceivable that A could exist without B; but it's not conceivable that B could exist without B.

Since you can make a statement about A that you can't make about B, A and B are not identical.

Brandon said...

Plantinga's argument is a version of Kripke's dualism argument; David Papineau has a fairly accessible account of Kripkean arguments.

X's actuality is not necessary for the argument to hold, because Plantinga is right that if X and Y have different modal properties (like different abilities or possibilities) they are not identical; this is true even if (as in the morning star case) they happen to be instantiated by the same object in the actual world -- the morning star argument doesn't show that a morning star can't also be an evening star, but it shows that being the morning star is not the same thing as being the evening star -- it would have been wholly possible for them to have been different objects in the sky. Likewise, Plantinga's argument does not show that things with minds can't be things with bodies, but it isn't intended to: the argument is supposed to show that being a mind and being a certain kind of body are not the same thing.

It's not an argument I agree with (I think showing possibility requires causal reasoning, so imagining or conceiving is not enough), but that's more or less the idea. But I agree with Maolsheachlann about Plantinga's impishness.

Matko said...

I plan to respond to several posts, but one each at a time.

PerplexedSeeker

The problem I have with the common argument that mental events are simply a different "mode of access" to the same underlying brain state available to neuroscience (which I guess is where the meaning/referent analogy comes into play) is that in the case of feeling, emotion etc., is that it's precisely the appearance that we're interested in. Specifically, why do some mechanical interactions have an appearance at all, when there's nothing there than could give rise to it? And if mental mechanisms have intrinsic conscious aspects, why don't other things? I don't see how this implication can avoid either some kind of elimination or panpsychism.

I'm not a Cartesian dualist, (I'm fascinated by idealism but I'm still studying the matter and haven't yet reached a final conclusion) but you still have the problem that conscious experience simply isn't necessary on a physicalist account of the mind. Everything which involves it could easily be done without it. Mental content is left dangling impotently from the brain.


Jaegwon Kim would say, and I'm ignorant if he changed his position, is that if you want to remain committed to physicalism, you have two choices concerning the phenomenal properties of the mental: epiphenomenalism or eliminativism. Either one should retain mental properties that resist reduction; qualia, for instance, and accept their casual impotence, or deny their reality in the physicalist account of the world. And there's no discernible difference between this two options, according to Kim. If the mental doesn't bring new causal power into the world, on one hand, and it is absorbed into the physical, on the other, you're just stating the same proposition. If something lacks any causal power to exert, why should it be treated as anything real? Epiphenomenalism or eliminativism assert the same thing, says Kim – the irreality of the mental.

Apropos panpsychism, in 2006, a book by Galen Strawson was published where he argues that physicalism entails panpsychism, several other philosopher reply, and he replies back. I haven't read it to appraise Strawson's argument, but it's interesting to know even serious philosopher entertain such ideas.

Ilíon said...

"... it's not clear to me why the fact that we can imagine something being true of A but not of B entails that A and B cannot be identical. ..."

I can see how the argument, *as it's being stated here* can lead to and justify this objection. Shoot! I'd make the objection, myslef, to an argument which turns on imagination.

However, as reality would have it, the theroetical property which Plantinga is imagining may be a property -- namely, that 'A' may exist even if 'B' does not -- is an actual property. This is true no matter which of the two entities is assigned to the two variables:

1) When Plantinga dies, his body (or brain) will still exist -- for a time. Yet, the self who is Plantinga will either not exist, or if that self continues to exist, it will exist independently of the matter comprising the dead body (or brain).

2) Even now, even as Plantinga lives, the self who is Plantinga exists in a different way than his mere material body (or brain) exists. For, Plantinga, the self, exists continuously/with-continuity (while that self exists); yet the apparent continuity of Plantinga's body (or brain) is a false perception: the matter comprising Plantinga's body (or brain) is in continuous flux.


It is, in fact, Plantinga-the-immaterial-self, who-exists-with-continuity, which imparts the apparent continuity to the mere material body of Plantinga.

Ilíon said...

Andrew: "So, if it is really true that it is *possible* that A is not identical to B, then it is actual that A is not identical to B."

Quire so.

Andrew: "The problem for Plantinga will be with trying to explain that it is possible for A to be distinct from B, and not just *think/imagine* something really similar to A as being distinct from B ..."

I agree; imagining that there exists a possibility of a difference is not enough to establish that there exists a possibility of a difference.

Fortunately, as see above, the difference is established.

Ilíon said...

Agellius: "It just occurred to me what he might mean, and I hope someone can correct me if I'm missing something:

Maybe what he's saying is that it's *conceivable* that I could exist without my body. But it's not conceivable that my body could exist without my body, because such a thing would be a contradiction.

Therefore you can make a statement about me ("A") that you can't make about my body ("B"): It's conceivable that A could exist without B; but it's not conceivable that B could exist without B.

Since you can make a statement about A that you can't make about B, A and B are not identical.
"

I suspect that may be, at least in part, what Plantinga was getting at. I wish things had been more fleshed out, and, well, stated differently (from "the other direction," so to speak).

Whether or not it's true in fact that the immaterial self can exist independently of (or without) the material body, it is not a logical contradiction to assert that it can (nor to assert that it does).

However, to assert that the material body can exist independently of (or without) the material body is to assert non-sense; it's to assert a statement which doesn't even rise to the level of being false.

Therefore, there exists something -- namely, a logically possible truth-claim -- which exists with respect to the immaterial self which does not exist with respect to the material body. Therefore, the two are not identical.

Matko said...

Andrew

So, if it is really true that it is *possible* that A is not identical to B, then it is actual that A is not identical to B.

How exactly? You only established that "A is identical to B" is not a necessary identity, but a contingent one. It could still turn out that A is identical to B. What you must establish is that it's impossible that A is identical to B. Or in this case, that mental state cannot be brain states.

What Plantinga did is to repeat Kripke's objection against type-type physicalism and reductionism. But nobody is a type-type physicalist since the sixties. Since then, more sophisticated materialist theories like functionalism and property dualism appeared. Functionalism with it's multiple realizability thesis is completely immune against the modal objection.

Ilíon said...

Andrew: "So, if it is really true that it is *possible* that A is not identical to B, then it is actual that A is not identical to B."

Matko: "How exactly? You only established that "A is identical to B" is not a necessary identity, but a contingent one. It could still turn out that A is identical to B. What you must establish is that it's impossible that A is identical to B."

There is no such thing as a "contingent identity" -- it's a logical impossibility, it's an oxymoron. And, "necessary identity" is ... if not quite a redundancy, an unnecessary expenditure of verbiage -- a particular identity cannot not be an identity, and it cannot not be the identity that it is.

Perhaps you're unwittingly conflating an allegation of identity for an identity? And, perhaps you're missing that Andrew said "... if it is really true that ..." and thus are misconstruing what he said/meant?

=======
Andrew: "So, if it is really true that it is *possible* that A is not identical to B, then it is actual that A is not identical to B."

The logic works thusly:
For any 'A' and 'B' --

* It is the case either that 'A' and 'B' are identical, or that they are not identical. It is not the case that they are both identical and not identical; it is not the case that they are neither identical nor not identical. (i.e. It is the case that 'A=B' or it is the case that 'A!=B' and there are no other possible cases.)

From the above, two statements:

* IF it is the case that 'A' and 'B' are actually identical, THEN necessarily it is the case that it is possible that 'A' and 'B' are identical.

* IF it is the case that 'A' and 'B' are not actually identical, THEN necessarily it is the case that it is not possible that 'A' and 'B' are identical.


Restating the immediately previous statement:
* IF it is the case that it is not possible that 'A' and 'B' are identical, THEN necessarily it is the case that 'A' and 'B' are not actually identical.

That is (using "#" to symbolize "possibly equal"):
IF '!(A#B)' THEN '!(A=B)'

Negating the prior sentence:
* IF '(A#B)' THEN '(A=B)'

Which is to say:
* IF it is the case that it is possible that 'A' and 'B' are identical, THEN necessarily it is the case that 'A' and 'B' are actually identical.

Ilíon said...

Matko: "What you must establish is that it's impossible that A is identical to B. Or in this case, that mental state cannot be brain states."

That's the easiest thing in the world to establish ... whether you will acknowledge it is a different matter.

If it is the case that mental states are indentical to brains states -- or even, if it is merely the case that mental states are *caused by* brains states -- then it impossible for us to think thoughts, to know truths, to reason, etc. This isn't exactly new -- the late British PM Balfour presented the case more than a century ago. Also, before that, Saint Chuckie, Himself, was quite aware of the problem.

I'm no one at all, and I certainly don't expect that you've ever heard of me, so don't misinterpret this as some sort of tooting my horn or anything like that. Anyway, on my little blog, I discuss this argument: (indirectly) here and here and here.

Ilíon said...

"(using "#" to symbolize "possibly equal")"

should be "(using "#" to symbolize "possibly IDENTICAL")"

Matko said...
This comment has been removed by the author.
Matko said...

As a philosophy undergraduate, I am thoroughly aware of Kripke's objection to mind-brain identity theory, but because of it, no one relapsed backed into substance dualism.

It only established that the identity materialists want is an a posteriori identity that can be established empirically. And I do not see any problems with the solution. The identity's apparent contingency is perhaps not caused by an ontic boundary, how Kripke considers he has demonstrated, but by an epistemic one. Because both members of the identity statement are perceivable from different perspective, the appearance of desperateness could be on the epistemological level and not on the ontological.

The main criticism of mind-brain identity theory came from other physicalists, who considered the type-type physicalism theory too restrictive. After it's demise, nonreductive physicalism came, and it is the mainstream position of contemporary philosophers of mind.

Ilíon said...

Does that translate into English?