Alvin Plantinga is widely regarded as one of the world’s leading Christian philosophers. Watch the video below and ask yourself, WTF?
So as not to spoil your fun, I’ll refrain from offering my take on the argument until readers have had a chance to comment.
I have no idea what Plantinga thinks he is proving.
I’ll grant that a person is not the same thing as a physical body, in the sense that they are conceptually different. It’s like house and home. What makes something my house, is that I own it. What makes something my home is that I live there.
Plantinga seems to think he is pointing to something stronger than a conceptual difference. I don’t see that he has made a case for that.
Obviously, the argument that I am not my body is true.
How could Star Trek transporters work if this were not the case?
But I think the real argument is about whether I can exist without any physical substrate. If there answer is no, as I think it must be, what sort of substrates are needed for continuity of personal identity? What properties and configuration of that substrate are needed to preserve my identity?
Also, if I can move my identity to multiple substrates, who owns the copyright?
Plantinga’s modal argument gets you started thinking about these issues.
Plantinga’s argument is this:
1. If my body were identical to me, then my body and me would have all and only the same properties.
2. But there are some modal properties that my body has that I don’t have and vice versa.
3. Therefore, I am not my body.
This argument is valid, I think. The problem is that his evidence for the second premise is no good. Lots of things that seem true to me aren’t true. It just may be that there aren’t any modal properties that my body has that I don’t have, even if it seems to me (I can conceive) that there are.
So yeah, it’s lame. And so is his ineffectual interlocutor.
I’ve been following Plantinga’s career for many years, and he kind of makes me sad. He is, I think (though you certainly can’t tell from this clip), an extremely smart guy. But his arguments–many of which are incredibly complicated and obtuse–seem to me to stem largely from Calvinist brain-washing and fear of dying. I know that’s entirely ad hominem, but I mean it in the kindest way possible. I think he could have been one of the greatest philosophers of our time if he’d been raised differently. Instead, his career has been largely that of a xtian apologist, wasting his incredible facility on nonsense.
In spite of that, however, one can learn a lot from his work. I highly recommend “De Dicto et De Re”, _The Nature of Necessity_ (before he gets to the ontological argument), and a lot of his stuff on warrant.
BruceS,
I wasn’t aware Star Trek transponders actually do work! Where can I find a dealer?
Here’s a slightly different way of phrasing the argument, inspired a bit more by Kripke than by Plantinga:
(1) According to materialism, persons are identical with their bodies.
(2) If persons are identical with their bodies, then necessarily each person has all the same properties as their bodies (including all of the modal properties).
(3) But we can conceive of persons as distinct from their bodies;
(4) Hence it is possible that persons are distinct from their bodies;
(5) But if persons were identical with their bodies, given that identity is a necessary relation, then it would not even be possible that persons are distinct from their bodies;
(6) Hence, since it is possible that persons are distinct from their bodies, persons cannot be identical with their bodies;
(7) and therefore materialism is false.
I know this shoemaker down the street who sells them. He claims he used to be a prince, but if you ignore that sort of nonsense, he will give you a good deal.
(I’m assuming you meant transporter, not transponder.)
I think that what Plantinga needs here — and seemingly thinks he can get for free from Kripke — is the Conceivability-Implies-Possibility Rule: if I can conceive of X, then it is possible that X. But if it is possible that X, then it is false that it is necessary that ~X.
Put otherwise: to show that it is false that X is necessary, it is sufficient to conceive of ~X.
What Plantinga seems to not recognize — and I think Kripke did, but I’m not sure about this — is that once you’re a realist about modal properties, this argument cannot work. For if you think — as Kripke apparently does — that modal properties are real (not just helpful ways of talking), and that science can discover them (as it did when it discovered that necessarily, water is H20), then what we can imagine to be the case doesn’t mean anything.
I can blithely assert, “suppose water were XYZ and not H20”. I can say that, maybe even believe it. There’s nothing contradictory about that supposition. If the only boundary to conceivability is logical principles, then in saying that “water is not H20” I’m not saying anything illogical. And yet we also know that it is not possible for anything to be water without being H20 — we know that because of our empirical discoveries of the modal properties of water.
And on that basis, it seems to me that even if one grants Plantinga his realism about modal properties, it is still the case that conceivability does not entail possibility, and so the entire argument is scuppered. From the fact that I can conceive of myself as being distinct from my body, nothing follows at all about what could be or must be the case.
The argument from because I say so.
Between this and the EAAN, which BruceS and I dispatched a few months ago, I think it’s safe to say that no one here is impressed with Plantinga. It does make me wonder why Plantinga was ever taken seriously to begin with. I suppose I’d have to read his earlier articles in order to find out.
Thanks, Bruce. Right–whichever one Scottie uses. I do want the guy’s name, but first I have to get this time travel thing to work right. I bought it from the prop guy on “Napoleon Dynamite”
If I get BOTH those devices humming right, it will be soooo awesome!!!!!!! I can transport/pond at the same time I’m going back in time so I won’t be stuck in, like 17th Century Massachusetts. I could go to Connecticut or something. I’m not even sure Thor can do that.
Jesus could, I guess, but had a lot of stuff going for him that I don’t, so it’s not really fair.
Kantian Naturalist,
As said, I think he’s a really smart guy. Total waste of talent.
Kantian Naturalist,
Exactly right. Sadly, trying to avoid the intensionality of conceivability contexts by the use of “de re attitudes” is a futile trick.
OK, that explains Plantinga.
But what about Chalmers arguments for property dualism? Too many Zombie movies in his formative teen years, perhaps?
I am clearly behind the curve on this because I don’t have a really good handle on what “modal properties” means. The critique makes sense to me in general, but I’m completely lost in the specifics.
Robin,
Modal properties are things like being possibly round or being necessarily physical. A couple principles about modal properties are that every possible property of some entity is necessarily possible of it, and every necessary property of something is necessarily necessary to it.
According to some philosophers, I’m only contingently nervous this morning, but am necessarily a person. I might have been calm today, but–Dr. Seuss notwithstanding–I couldn’t have been three green tomatoes.
Kantian Naturalist,
The fact he is taken seriously speaks to the poverty of (c) Sophisticated Theology.
Watch “the prestige”. They would work by creating another you, not moving the current you. You die every time and we get a new you after, with the same memories. Perhaps “you” die every time you go to sleep?
It’s the term that Plantinga uses. “Modality” encompasses necessity, possibility and actuality.
Plantinga wants to say that modality is best understood in terms of modal properties: that when I say, “it is necessarily the case that water is H2O,” I am saying, of water, that it has the property of necessarily being H20. And when I say, “It could be raining outside,” I am saying, of the local weather, that it has the property of possibly being in a state of raining.
One might be tempted to think of necessity in strictly cognitive terms — to say that “it is necessarily the case that X” is just to say, “we would be extremely reluctant to give up on asserting that X is the case”. This is roughly Quine’s view, and whatever its merits, it’s quite hostile to Kripke-style realism about modal properties — where necessity and possibility are properties of the things themselves — and not just features of our ways of talking about them.
(A bit of history, for the curious: in 1970, twenty years after Quine published “Two Dogmas of Empiricism,” Saul Kripke gave the lectures that became Naming and Necessity. These lectures provoked a major split within analytic philosophy — the vast majority of philosophers were excited about the resurgence of realism, and between Kripke, David Lewis, David Armstrong, and a few others, led to the revival of analytic metaphysics. Only a few places held onto the earlier, pre-metaphysical, analytic pragmatism of Quine and Sellars, though the renaissance has been slowly building for the past twenty or so years and I’m optimistic about it.)
Right, his name.
The thing is, I can imagine a world where his prince/cobbler swap story is true.
Yet is seems that on this world his name is the cobblers name.
Does that mean he has the same name on every world you might possibly transport to? (Note, by the way, that the latest transporters now have access to possible worlds — as predicted by various Star Trek episodes).
Richardthughes,
I think you have to read a couple of his books to say that. He’s highly regarded not because anybody (except van Inwagen) agrees with him about anything, but because he’s a formidable argument producer. (Athough, again, you’d never know it from this clip.) His stuff is difficult and clever and well-thought out. Just always wrongheaded.
And, I have to say, it’s scary to insist on his being wrong when I realize he’s smarter than I am. It’s partly a kind of inference from “Are you shitting me with that stuff? It turns out that Dutch Calvinists were right about everything–it just took developments in 20th Century modal philosophy and epistemology to demonstrate it?!? I mean, come on.”
walto,
Right — it’s a realistic interpretation (in the sense of metaphysical realism) of modal logic, if I understand the language correctly. (I’m a recovering ‘Continental’ philosopher, so this stuff isn’t part of my training.)
Whoosh.
The sound of words flying over my head.
If conceivable distinctions were real, beggars could ride. And Hogwarts would need to add a lot more classrooms.
If I am not only my body, but also exist Somewhere Else, what happens if in walking around my kitchen I hit my head on a cabinet and fall down unconscious? Is my spirit Elsewhere also then unconscious? Or could it be doing useful work in the kitchen while I lie there knocked out? Or at least useful meal planning?
And if this dual existence is true, what about other mammals (chimps, mice, etc.)? Are mice really meta-mice? We can conceive of a meta-mouse, so using Plantinga’s argument the mouse “is” more than just its material body.
What about earthworms? Where does Plantinga draw the line, and how? (We know the answer to “why”).
(In the video Plantinga also shows the sophistication of his biological knowledge. He thinks that cockroaches are beetles and that they have eight legs).
Right, some of it comes down to when is “another you” really just “you”, only later. Lots of philosophy of personal identity is about this and more complex scenarios. Unfortunately, we have to wait for transporters to resolve all of it scientifically.
I think that’s a perfectly reasonable inference!
Would you mind explaining this?
No dice. “Properly basic” is equally poor. “But he uses s5 model logic!” – don’t confuse a smart guy with a good argument.
Kantian Naturalist,
Yes, Plantinga is a modal realist. But you can be a modal realist without believing that the ontological argument is sound, just as you can agree with Plantinga’s understanding of warrant without inferring that the existence of reason requires that there is a God. As we’ve both said, you can stop his argument in this clip by denying the second premise, whether there are modal properties or not. It’s too bad the interlocutor in that clip didn’t understand that.
Does it help that it is intensionality with as s. Probably not much if you are like me.(not meant to be negative — it is legitimate philosophers jargon).
Richardthughes,
You’re right to distinguish smart guys from good arguments. But seeing that somebody is smart can (ought to?) give one pause. Anyhow, I agree with you that his arguments are generally bad.
Kantian Naturalist,
De re, it’s believing OF X that it is possibly F rather than believing the proposition that possibly X is F.
petrushka,
Intensional contexts are what allow the following to be true:
Jones believes that Clark Kent is a weakling
Clark Kent is Superman
Jones doesn’t believe that Superman is a weakling
Some modal philosophers think you can get the conclusion to be false by writing it this way (de re or of the thing):
Clark Kent is such that Jones believes of him that he is a weakling
Clark Kent is Superman
Therefore Superman (that guy, whatever anybody may think of him) is such that Jones believes of him that he is a weakling.
Hope that helps.
It seems to me that the real problem with his argument is that to prove our minds are not our bodies he simply takes takes it for granted that there is an afterlife.Not only could our minds not be our bodies but there would be many other requirements for life after death to exist. Whats this mistake called..Affirming the Consequent?
I think the way he was defining the identify of things was rather dubious. Any 2 objects will have some things in common and some differences. This doesnt reflect an outside reality, it has more to do with how our minds parse reality.
He ignores the possibily that personal identity arises from the workings of the brain. Cut off your arm and you’re still you. Disconnect all your neurons and ‘you’ cease to exist
I am not me. I can imagine me, but me can’t imagine I. etc etc.
Is there a typo in this?
Assuming I get the intended gist, I would respond as follows.
Hamlet is a Dane obsessed with avenging his father’s murder.
Hamlet is Kenneth Branagh
Therefore Kenneth Branagh is a Dane obsessed with avenging his father.
Whatever is is we “really” are, it is not the same thing as the roles we play and the things we do. Or maybe it is the sum of them.
But this sounds like equivocation to me. It’s a really ugly kind of reasoning.
Edited for less stupid. Maybe.
Walto and KN,
I must confess that your explanations, while well-stated, do not mean much to me as I’m afraid I clearly don’t have a frame of reference to understand the terms you are using. For example, what do you mean by ““Modality” encompasses necessity, possibility and actuality” and “it is necessarily the case that water is H2O.” To me, saying water is H2O is redundant; the terms are synonymous. So saying that “it is necessarily the case…” is a tautology.
Try this – in accordance with Plantinga’s argument, what modal properties could I have that my body does not have and what modal properties could my body have that I don’t have. I really can’t wrap my head around the idea that they could be different.
Here is my non-philosphers take on his argument in case it helps you.
I think the fact that such properties could exist is enough for the argument to make a start. (If you are a math person, it is an existence proof, not a constructive proof; if you are not a math person, never mind that point).
Here is my rough summary.
I can conceive of a world where a person is separate from his or her body. (This is the possible world part).
Now if I can conceive the two are different, there must be some property of the two that allows me to do make this conceptual distinction.
Now if things are identical, they must have the same properties in any possible world = any world I can conceive of. Not just in our world, but in any possible world. If they do not, then they are not identical. This is the Liebniz bit.
Hence they could be different in our world.
This may also help: there is a very similar argument about consciousness not being physical. It relies on philosophical zombies: beings who are physically exactly the same as us, who behave exactly as we do, but yet who have no conscious internal experiences. Now the argument goes on to say that if I can conceive of such beings, then there be some non-physical property of consciousness that might be the case in our world.
I am sure there are lots of holes in that summary that a more philosophically sophisticated person than me would point out. (eg, many distinguish between conceivable and metaphysically possible). But that helps me wrap my head around the issues. I hope it helps you.
Robin,
The point is this: yes, water is H20. We all know this. But is it possible that water isn’t H20?
Here I am, Kantian Naturalist, writing this comment. But could the world have been such that I decided not to log in this morning? Of course. I could have passed away in my sleep last night, or received an emergency phone call this morning, or . . . there are infinitely many possibilities which, had they been realized, I would not be posting this comment.
Now, given that thought, could the entire world have been such that there’s this transparent liquid which has all the sensible qualities of water, but which is not composed of two hydrogen atoms and one oxygen atom? Does that even seem coherent as a mere fanciful supposition? Or is reality such that nothing could possibly be water without also being H20?
Plantinga thinks they different in at least one modal property: that it is possible for me to exist when my body does not exist. My possible existence is consistent with the possible non-existence of my body. “And how do you know that, Professor Plantinga?”, we ask. “That’s easy — it’s because I can conceive of myself as existing without my body!”
I am actually not sure that he can conceive of what he claims to conceive. The cases of Gregor Samsa, or any decent science-fiction, show us that we can conceive of ourselves as having very different kinds of bodies than what we actually have — that doesn’t show that we can conceive of ourselves as not having any body at all.
So even granting all the dubious premises, Plantinga’s argument shows that I am not necessarily identical with this particular physical body, not that I’m not necessarily identical with some physical body. For all that Plantinga has shown us, it could very well be the case that necessarily, every mind is embodied, and that this is a modal property of minds that neuroscience discovers, just as chemistry has discovered that necessarily, water is H20.
If wishes were horses.
Ahhhhh! Ok…the light bulb is now flickering. I think I get the mental construction for modality. Thanks!
(Booooooo…that strikes me as a really weak question beg)
Hmm…interesting. Ok.
I’ve actually been wondering of late whether identity will automatically re-establish in the physical universe after a death. That is, not whether there is reincarnation, but whether fixed perspective identity (the “I” looking out of eyes on the world) comes around again simply by virtue of a given organization of molecules. If identity is indeed embedded in specific bodily arrangements, it stands to reason that after some amount of time across multiverses, that specific arrangement of matter will come up again. I doubt memories from past arrangements could be maintained, but it is interesting to think that this particular perspective of awareness of the world could very well arise again (and again and again and…)
Excellent Bruce! Nice summary. Coupled with what KN and Walto provided, I think I’m beginning to get the picture.
KN wrote:
“The point is this: yes, water is H20. We all know this. But is it possible that water isn’t H20?”
You have to be careful with that locution, because it’s ambiguous. Plantinga and Kripke aren’t talking about epistemic possibility here (i.e., I MIGHT be wrong about H20 being water; we might discover it’s actually something else). They’re talking about metaphysical necessity: supposing that water actually IS H20, is there a possible world (could it have been) that they were not identical. The intuition is: If the morning star actually IS the evening star–the very same planet orbiting the sun–how could they not have been identical to each other? That would mean that something wasn’t identical with itself. It’s not that the morning star might not have been visible in the evening. Being visible in the evening is a contingent property of that planet that is both the morning star and the evening star. What’s necessary is that everything is self-identical, and couldn’t have not been.
Yeah, I’d also like to thank Bruce and KN for clarifying what, for me, was Platinga throwing up an incomprehensible mess all over the floor.
Robin said:
Why wouldn’t the particular memories be reproducible? Aren’t memories just particular arrangements of matter in the here and now?
Have you heard of the quantum immortality thought-experiment? From wiki:
I would suggest, though, that the subjective experience of “life after death” could just as well be one of the kinds of survival iterations available to consciousness to avoid it’s own extinction.
BruceS,
That’s a nice job, Bruce. The only thing I’d clarify is that when you say
“Now if things are identical, they must have the same properties in any possible world = any world I can conceive of.”
you have to mean (and I think you DID) that they must have the same properties as each other in any possible world. Because, of course, they (that is IT) could have many different properties in different possible worlds than IT has in the actual world. But since there’s only ONE thing, IT can’t have different properties than itself in any world.
And for those who think the whole notion of possible worlds is silly, you can just think of it as a heuristic device. “There is a possible world where X is F” is just a fancy way of saying that X might have been F.
Your speculation is in agreement with what some cosmologists believe to be the case.
Specifically, based on a scenario for how cosmic inflation works, they believe that inflation continues indefinitely and produces an infinite number of island universes.
But there are only a finite number of possible states, due to quantum mechanics dictating that states are indistinguishable below some level of measurement.
Therefore all states of our universe, including you, must occur infinitely often in other universes. Or, to be consistent with the theme of the OP, I should say “you” occur infinitely. (The scare quotes to leave open the question of whether each of those occurrences is really is the same person as you, but using a different physical body.
Unfortunately, we cannot communicate with these universes, only infer their existence from the physics which governs ours.
Good thing we cannot communicate: I am sure the long distance charges would be prohibitive.
You and I must be reading the same popular science books, William!
(see my post above).
How can memories be separate from the arrangement of molecules?
“intended” — good one
I think walto is trying to describe how philosophers use intensional, with an s. Here is my take.
It can be used to describe a particular form of language context. This usage relies on the fact that two names can refer to the same thing in the world, like Clark Kent and Superman. (OK, the comics world).
You can say:
Superman is strong.
Now if you substitute a another name for Superman, you cannot make this a false statement. For example:
Clark Kent is strong
This is still true always. So that language context is NOT intensional.
But the following language context IS intensional:
Mary believes that Superman is strong.
Now one could substitute Clark Kent for Superman in the above and end up with:
Mary believes that Clark Kent strong.
But this could very well be false, for example if Mary grew up in a room with no color and never read a comic book or saw a movie. Oh, wait, I don’t need the no color bit. Forget that part.
The point is the “Mary believes that” bit makes the language context intensional because I can change the truth value of the statement by substituting a name that refers to the same thing in the bit after “that”.
Now as for de re and de dicto: I think I understand those immediately after I read a definition, but it never sticks when I try to apply what I read. So I am going to stop for today.
Thanks for that clarification and comment.
No matter how old one gets, it is still nice to get a gold star from the teacher.