A Seldom Considered Argument for Dualism

[JimL]

If, in fact, material objects cannot continue to exist after the loss of their parts, then, if you are a material object, when that occurred, you would cease to exist. The individual left behind would be a different individual, a duplicate of yourself.

Well that would be true if we assume that material objects are what you would call mereological simples, but the material objects that we are considering are not material mereological simples, they, bodies, are perhaps composed of material mereological simples but they themselves, considered as individual objects are composed of parts. It would, it seems to me, be irrelevent to even ask the question as to whether or not a material mereological simple could continue to exist after the loss of one of their parts, because obviously they don't have any parts, but the question becomes a different question when we consider that the material object in question is not a mereological simple, but a conglomoration of parts. Although it is probably immpossible to make such an exact duplicate of a material object, particularly the exact structure of the human nervous system and brain, but theoretically speaking, I think that if you could, you would have two of the exact same people.

[Kenny]

Well that would be true if we assume that material objects are what you would call mereological simples, but the material objects that we are considering are not material mereological simples, they, bodies, are perhaps composed of material mereological simples but they themselves, considered as individual objects are composed of parts. It would, it seems to me, be irrelevent to even ask the question as to whether or not a material mereological simple could continue to exist after the loss of one of their parts, because obviously they don't have any parts, but the question becomes a different question when we consider that the material object in question is not a mereological simple, but a conglomoration of parts. Although it is probably immpossible to make such an exact duplicate of a material object, particularly the exact structure of the human nervous system and brain, but theoretically speaking, I think that if you could, you would have two of the exact same people.

It’s not possible for there to be “two of the exact same people,” not, at any rate, if the “exact sameness” relation here is that of numerical identity. If person x and person y are numerically identical, then there are not two of “them” (too bad English demands the plural here); there’s only one. It is possible for there to be two individuals that are qualitatively exactly the same, but as I pointed out before, what is at issue here is numerical sameness, not qualitative sameness.

[JimL]

It’s not possible for there to be “two of the exact same people,” not, at any rate, if the “exact sameness” relation here is that of numerical identity. If person x and person y are numerically identical, then there are not two of “them” (too bad English demands the plural here); there’s only one. It is possible for there to be two individuals that are qualitatively exactly the same, but as I pointed out before, what is at issue here is numerical sameness, not qualitative sameness.

Aha! I think that I have found the reason for my difficulty in understanding your argument. Your conclusion "that if Human persons are material objects then they can't exist after the loss of certain parts," suggests to the mind that Human persons are mereological simples, which as we know, if human persons are material objects, then they are not mereological simples but rather they are a conglomeration of mereological simples, or a conglomoration of material objects. It would be true to say that a mereological simple could not survive the loss of a part because as you have made clear to me, mereological simples are not made up of parts, and therefore to say that a mereological simple object continues to exist after the loss of a part would be ludicrous, because a loss of a part would be anihilation of the whole. But human persons, if they are material objects, are not mereological simples, they are a conglomoration of parts and so losing certain of those parts would not anihilate the material object/person as a whole, it could be said to continue in its existence, though it may be missing certain parts. Does that make sense to you?

[Carrikature]

The issue here isn’t about what one might refer to as qualitative sameness (having the same properties as) but numerical sameness (being one and the same thing as). For example, we might say that two spatially separated spheres that are intrinsically exactly alike are qualitatively the same, but clearly they aren’t numerically the same (there’s two of them after all). When something undergoes a qualitative change, it ceases to be qualitatively the same as it was previously, but not numerically the same as it was previously (otherwise, it wouldn’t undergo change; it would simply cease to exist and be replaced by something else).

I would say that whatever concepts are (if indeed there are such things) they are things that thinking beings have, but they themselves are not thinking beings. Likewise, I would say that whatever human persons are, they (or at least the paradigmatic examples of them) are thinking beings. These two claims together (which each strike me as obviously true) entail that whatever human persons are, they are not concepts.

I’m not even sure I understand what it would be for a concept to literally have parts.

I think it is safe to say that something can be qualitatively the same while being quantitatively different. That is, two separate trees will have the same properties (e.g. height, weight, bark, leaves, etc) while having different values for those properties (one could be 2' taller than the other). This implies, then, that an object can undergo a change in a value or values for certain properties without changing its identity, which is essentially what you're suggesting. However, the difference is that I don't take this to be specific to human persons.

Whatever 'immaterial' aspect survives the change in quantitative values, it is not required to be a soul. This is why I mention understanding 'human being' as a concept. A concept is not necessarily real, anymore than numbers are, but remains useful to convey meaning. Our concept of what qualitative properties human beings have is not changed due to a change of its quantitative values. We do, however, begin to ascribe descriptors (such as paraplegic, etc) to those beings we recognize as missing some part of 'normalcy' but which still fit the basic properties of a 'human being'. In fact, this is the ethical dilemma with the 'brain dead'.

[nightbringer]

Kenny, I've been thinking, there are things one could say to put pressure on the person who denies: "(P1) If human persons are material objects, human persons can strictly survive the loss of some of their parts."

Imagine that Sally (S) robs a bank (call this event R) in 1975 (t1) and is caught. However, due to various complications with the prosecution, she is not put on trial until 2011 (t2). During this time, via natural processes, various atoms that compose her body have been replaced with other ones. Now for the argument.

1. A person can be morally accountable for an event iff they are numerically identical to an object that causally contributed to that event.
2. S at t1 is the only object that causally contributed to R which S at t2 could be numerically identical to.
3. Therefore, S can be morally accountable for R's occurrence at t1, even at t2, iff S at t2 is numerically identical to S at t1.
4. If S is a material object, S lost some composing parts between t1 and t2.
5. Therefore, if S is a material object, S can be morally accountable for R's occurrence at t1, even at t2, iff S strictly survives the loss of some of her parts.
6. S is morally accountable for R's occurrence at t1, even at t2.
7. Therefore, either S is an immaterial object, or S is a material object that survives the loss of some of her parts.

[Kenny]

Aha! I think that I have found the reason for my difficulty in understanding your argument. Your conclusion "that if Human persons are material objects then they can't exist after the loss of certain parts," suggests to the mind that Human persons are mereological simples

No. I provided an argument, the body-minus argument (which, btw, is definitely not mine, but a famous argument dating all the way back to the Greeks and one that is frequently discussed in mereology), for the conclusion that no composite material object continues to exist after the loss of some of its parts.

it could be said to continue in its existence, though it may be missing certain parts. Does that make sense to you?

It makes sense. But if the body-minus argument is sound, it’s not true. Now, there are ways to challenge the body-minus argument. Find a premise to deny, and we’ll talk.

[Kenny]

I think it is safe to say that something can be qualitatively the same while being quantitatively different.

When philosophers speak of ‘qualitative’ sameness, they’re talking about the sharing of properties, including what you are referring to as “quantitative” properties.

Now, if we want to sensibly speak of two objects being qualitatively the same but not numerically identical, we do need a restriction when it comes to what sorts of properties we’re talking about. We can’t let in what are sometimes called “impure” properties, these being properties that pertain to the numerical identity of a thing – e.g. the property of being identical to Kenny. Obviously, no two objects could share all of the same properties, including their impure properties – because, in that case, “they” would just be numerically identical – there wouldn’t be two of them, only one. But the contrast here is not between qualitative properties and quantitative properties (the way this terminology is used, what you are calling “quantitative” properties are a species of qualitative properties).

Just an FYI.

Whatever 'immaterial' aspect survives the change in quantitative values, it is not required to be a soul.

Well, either human persons are material beings or immaterial ones. If the argument I provided is sound, they’re not material ones; so (if the argument is sound) they must be immaterial ones. I grant that the argument doesn’t yield much information about what sort of immaterial things human persons are. But I have just chosen to label the immaterial things that human persons are as “souls”. I take it though that we do know some things about human persons that rule out certain types of immaterial objects as candidates for what souls are. E.g. we know that human persons have causal powers, so, whatever souls are (they being human persons), they must not be immaterial objects of a sort that lack causal powers (e.g. they must not be abstract objects).

This is why I mention understanding 'human being' as a concept. A concept is not necessarily real, anymore than numbers are, but remains useful to convey meaning. Our concept of what qualitative properties human beings have is not changed due to a change of its quantitative values. We do, however, begin to ascribe descriptors (such as paraplegic, etc) to those beings we recognize as missing some part of 'normalcy' but which still fit the basic properties of a 'human being'. In fact, this is the ethical dilemma with the 'brain dead'.

It may be that a source of our disagreement is that you seem to think that all issues surrounding the question of what sorts of changes human persons can undergo are purely conceptual questions. This suggests that you take a kind of anti-realist view of human persons, that you think there are no objective, mind independent facts to be had concerning the matter of what changes human persons can survive.

I don’t have much to say against that view, except that it strikes me as an extremely implausible view of human persons. I think that the philosopher Roderick Chisholm illustrated its implausibility quite well:

SOURCE

Chisholm finds this incredible. He recalls an argument attributed to C. S. Peirce: suppose you are about to undergo surgery. Suppose you are told that you can save a lot of money by taking the surgery without anesthesia. Instead, you will be given amnesia-inducing drugs that will make you forget the pain afterwards. Still you might be uneasy, since you might fear that the man undergoing the painful surgery will be you. Chisholm then continues:


Suppose that others come to you — friends, relatives, judges, clergymen — and they offer the following advice and assurance. “Have no fear,” they will say.“Take the cheaper operation and we will take care of everything. We will lay down the convention that the man on the table is not you, Jones, but is Smith.” What oughtto be obvious to you, it seems to me, is that the laying down of this convention should have no effect at all upon your decision. For you may still ask, “But won't that person be I?” and, it seems to me, the question has an answer. [P&O: 111]

[Kenny]

Kenny, I've been thinking, there are things one could say to put pressure on the person who denies: "(P1) If human persons are material objects, human persons can strictly survive the loss of some of their parts."

Obviously, I’m sympathetic. But I think someone who is inclined to deny P1 and who is also sympathetic toward the sort of Chisholmian line that I take about the persistence of commonsense material objects would also be inclined to say that we should replace your premise 1 with

1*: A person can be morally accountable for an event iff s/he is the same person as the one that causally contributed to that event.

And then the denier of P1 who is sympathetic to my Chisholmian line would then say that it is not a necessary condition for x’s being the same person as y that x be numerically identical to y, no more than it is a necessary condition for x’s being the same car as y that x be numerically identical to y.

[Carrikature]

When philosophers speak of ‘qualitative’ sameness, they’re talking about the sharing of properties, including what you are referring to as “quantitative” properties.

Now, if we want to sensibly speak of two objects being qualitatively the same but not numerically identical, we do need a restriction when it comes to what sorts of properties we’re talking about. We can’t let in what are sometimes called “impure” properties, these being properties that pertain to the numerical identity of a thing – e.g. the property of being identical to Kenny. Obviously, no two objects could share all of the same properties, including their impure properties – because, in that case, “they” would just be numerically identical – there wouldn’t be two of them, only one. But the contrast here is not between qualitative properties and quantitative properties (the way this terminology is used, what you are calling “quantitative” properties are a species of qualitative properties).

Just an FYI.

Oh.

Well that does explain why I was having a hard time parsing your 'numerical identity' usage...

Well, either human persons are material beings or immaterial ones. If the argument I provided is sound, they’re not material ones; so (if the argument is sound) they must be immaterial ones. I grant that the argument doesn’t yield much information about what sort of immaterial things human persons are. But I have just chosen to label the immaterial things that human persons are as “souls”. I take it though that we do know some things about human persons that rule out certain types of immaterial objects as candidates for what souls are. E.g. we know that human persons have causal powers, so, whatever souls are (they being human persons), they must not be immaterial objects of a sort that lack causal powers (e.g. they must not be abstract objects).

Doesn't the definition of dualism entail that they are both? I do agree, however, that your argument does lend credence to the idea that there is some sort of immaterial aspect. You're right that the argument doesn't give us much information about what that aspect is. My biggest complaint is that this lack of information means that (imo) you haven't sufficiently established that this immaterial aspect is unique to humans. Until then, I'm not sure you can safely call this aspect a 'soul' (lest you run the risk of ascribing non-thinking objects a soul).

It may be that a source of our disagreement is that you seem to think that all issues surrounding the question of what sorts of changes human persons can undergo are purely conceptual questions. This suggests that you take a kind of anti-realist view of human persons, that you think there are no objective, mind independent facts to be had concerning the matter of what changes human persons can survive.

Hmm. I think there are objective, mind-independent facts concerning what changes human persons can survive. I just don't think there are very many of them, and, for that matter, I think they are essentially material in nature. As scientific knowledge progresses, I think these objective facts become fewer and fewer in number. I also think that most people mistake their own opinions for objective facts.

I don’t have much to say against that view, except that it strikes me as an extremely implausible view of human persons. I think that the philosopher Roderick Chisholm illustrated its implausibility quite well:

SOURCE

Interesting quote. I think Chisholm hits the nail on the head, but is perhaps answering a different question. It's of course absurd to think that another person can simply declare you 'not you' and expect it hold any weight. (Jones knows full well that whatever Smith endures will also be endured by Jones.) However, I don't think the issue is that we have any trouble distinguishing WHO we are. Rather, we don't know WHAT we are. Even worse, we struggle to know what something else is.

I would suggest that we identify ourselves by the shell we posses without undue concern (in general) for the inner-workings. This is perhaps too far off-topic, though, and might be better suited to its own thread.

[JimL]

No. I provided an argument, the body-minus argument (which, btw, is definitely not mine, but a famous argument dating all the way back to the Greeks and one that is frequently discussed in mereology), for the conclusion that no composite material object continues to exist after the loss of some of its parts.



It makes sense. But if the body-minus argument is sound, it’s not true. Now, there are ways to challenge the body-minus argument. Find a premise to deny, and we’ll talk.

I have to admit that I have gone over your argument again and again and I do not see anything in your argument except that the human person, aka a composite material object, aka a body, which at t1 lost a part, aka its pinky, becomes therefore at t1 a human person, aka a composite material object, aka a body, which continues to exist, though its continued existence is minus its pinky. I'm not sure what your seeing in that argument, but to me there is nothing there.

[Kenny]

I have to admit that I have gone over your argument again and again and I do not see anything in your argument except that the human person, aka a composite material object, aka a body, which at t1 lost a part, aka its pinky, becomes therefore at t1 a human person, aka a composite material object, aka a body, which continues to exist, though its continued existence is minus its pinky. I'm not sure what your seeing in that argument, but to me there is nothing there.

First, the body-minus argument is intended to show (via generalization from the arbitrary case) that no material object (whether it’s the body of a human person, a tree, my desk, etc.) can strictly survive the loss of one of its parts. So it may help aid your understanding (by way of eliminating any distractions caused by the issue of whether or not the object in question is a human person) to run the same argument with a different kind of material object – say a tree losing a branch, instead of a human body losing a pinky.

Second, the argument is logically valid (i.e. the conclusion logically follows from the premises). And the conclusion of the argument is that the original material body (the one that began with the pinky as a part) no longer exists. Since the argument is logically valid, if you want to consistently deny the conclusion, you must deny one of the premises. The premises of the argument are found on lines 1, 2, 3 and 6. The premises all strike me as true, but there are ways that philosophers have found to deny various ones of them (all of these ways, in my opinion, involve committing oneself to claims that are less plausible than the premises themselves are – but, of course, this being a typical philosophical debate, not everyone agrees).

The bottom line, though, is that the argument is valid and the conclusion is that the original material body no longer exists. So, to respond to the argument, you need to find some premises to challenge. Otherwise, you’re simply not engaging with the argument.

[JimL]

First, the body-minus argument is intended to show (via generalization from the arbitrary case) that no material object (whether it’s the body of a human person, a tree, my desk, etc.) can strictly survive the loss of one of its parts. So it may help aid your understanding (by way of eliminating any distractions caused by the issue of whether or not the object in question is a human person) to run the same argument with a different kind of material object – say a tree losing a branch, instead of a human body losing a pinky.

Okay, lets take the example of a tree then, which I remember someone had brought up earlier in this discussion. When a tree loses a branch what exactly do you mean when you assert that the tree does not strickly survive? Surely you do not mean to say, since the tree still stands before you, that the tree no longer exists? So what exactly is the term "strickly" in the phrase "strickly survive" meant to convey?

Second, the argument is logically valid (i.e. the conclusion logically follows from the premises). And the conclusion of the argument is that the original material body (the one that began with the pinky as a part) no longer exists. Since the argument is logically valid, if you want to consistently deny the conclusion, you must deny one of the premises. The premises of the argument are found on lines 1, 2, 3 and 6. The premises all strike me as true, but there are ways that philosophers have found to deny various ones of them (all of these ways, in my opinion, involve committing oneself to claims that are less plausible than the premises themselves are – but, of course, this being a typical philosophical debate, not everyone agrees).

But it is obvious that the original material body, i.e. the tree, though minus a branch, since it still stands before you, does continue to exist. So by what reason or logic do you conclude that that which obviously still exists, somehow no longer does exist?

The bottom line, though, is that the argument is valid and the conclusion is that the original material body no longer exists. So, to respond to the argument, you need to find some premises to challenge. Otherwise, you’re simply not engaging with the argument.

But, and I mean no offense, the argument isn't sound nor is its conclusion valid just because you say that it is valid. To assert that a tree is no longer the same tree, or that that tree no longer exists after losing a branch when we can plainly see that, although it is absent a branch, it is indeed the same tree, and that that same tree does indeed continue to exist, doesn't seem to me to be a logically valid argument.

[Kenny]

Okay, lets take the example of a tree then, which I remember someone had brought up earlier in this discussion. When a tree loses a branch what exactly do you mean when you assert that the tree does not strickly survive?

I mean that the material object that was that tree no longer exists.

Surely you do not mean to say, since the tree still stands before you, that the tree no longer exists?

A material object stands before me that is a tree. But it is not identical to the material object that was a tree there before the annihilation of its branch. The latter object no longer exists. The tree that stands there is a material object that, prior to the annihilation of the branch, was not a tree, but a large proper part of a tree. Now that the original object that was a tree is gone, one of its former parts is there to take over the job.

So what exactly is the term "strickly" in the phrase "strickly survive" meant to convey?

I defined that phrase for you in the OP. An object strictly survives an occurrence if and only if it exists before the occurrence and it exists after the occurrence. There’s a “loose” sense in which the tree can be said to survive. It survives in a way that is analogous to how the Presidency might survive an assassination of the President -- by having a successor take over the role. But it doesn’t survive in the sense that it continues to exist.

But it is obvious that the original material body, i.e. the tree, though minus a branch, since it still stands before you, does continue to exist.

What stands before me is a different object than that one, one that used to be a proper part of that one.

So by what reason or logic do you conclude that that which obviously still exists, somehow no longer does exist?

It doesn’t obviously still exist. What’s obvious is that there is still a tree there. What isn’t obvious is that the tree that is standing there is identical to the one that was there prior to the annihilation of its branch. Not only is that not obvious, I think that the body-minus argument gives us a good reason to think that it is false.

But, and I mean no offense, the argument isn't sound nor is its conclusion valid just because you say that it is valid.

Conclusions are not the sorts of things that are valid (not in the way that the term ‘valid’ is used in logic, which is the way that I am using it). Conclusions are true or false. Arguments are valid (or invalid). An argument is valid if and only if its conclusion logically follows from its premises (i.e. if and only if it is not logically possible for all of its premises to be true but for its conclusion to be false). And you’re right that the argument is not valid because I say it is. It’s valid because its conclusion does in fact follow from the premises. And this is not simply a matter of opinion; it’s an objective fact, one that anyone who understands basic formal logic can check for his or her self, in the same way that one can check the validity of the inferences made in a mathematical proof.

What is debatable is whether or not the argument is sound; an argument is sound if and only if it is valid and all of its premises are true. Any sound argument is guaranteed (by virtue of being sound) to have a true conclusion. So, since the body-minus argument is valid, its conclusion is false only if one of its premises is false.

To assert that a tree is no longer the same tree, or that that tree no longer exists after losing a branch when we can plainly see that, although it is absent a branch, it is indeed the same tree, and that that same tree does indeed continue to exist, doesn't seem to me to be a logically valid argument.

It’s not up for rational dispute whether the argument is valid. That’s just a verifiable logical fact. I agree that it is up for rational dispute whether the argument is sound. But since it is valid, to challenge its soundness, you must challenge the truth of one or more of its premises. You haven’t done that yet. You’ve simply denied the conclusion of the argument without actually engaging the argument.

[Kenny]

Doesn't the definition of dualism entail that they are both?

No. As I am using the term ‘immaterial’, it is synonymous with ‘not material’. Obviously no object can be both material and not material (to say that an object is both material and not material is to endorse a contradiction). Perhaps (though I doubt it) an object can have both a material and a non-material part, but such an object, I would say is not material in the same way in which a soccer ball with a black and white exterior, though it has black parts, is not black.

Dualism (more precisely, substance dualism) is just the view that any given human person is either identical to an immaterial object or at least in part composed or constituted by an immaterial object.

Some dualists think that human persons are body-soul composites of some sort. But I (and many other philosophers, both dualists and materialists about human persons alike) think that such a position is fraught with difficulties. Other dualists (like myself) take human persons to be identical to immaterial souls. We are embodied, given this view, but our bodies do not in any way partially compose or constitute us. What we are are immaterial souls.

My biggest complaint is that this lack of information means that (imo) you haven't sufficiently established that this immaterial aspect is unique to humans.

I don’t see why you think that this is an objection to the argument. It may well be that the argument establishes its conclusion while leaving us in the dark about a lot of issues raised by its conclusion, but that is no objection to the soundness of the argument. And, frankly, I’m glad it doesn’t establish the above, because I think the above is false. I think there are non-humans that have souls. I believe, for example, that conscious non-human animals have souls (and I think that every sensible dualist should – but that’s another topic).

[JimL]

I mean that the material object that was that tree no longer exists.

Right, but if the material object, unlike that of a rock, is a living animate kind of matter, something which can be said to either survive or not survive, then the fact that it continues to survive after the loss of a part I think affirms the conlusion to the premise that if human persons are immaterial objects, then they obviously can and do survive the loss of a part. The use of the term "strictly" as in "strictly" survives, it seems to me is superflous, as it only means that a living material object, i.e. a human person or a tree, though it survives, though it continues to exist, it does so absent a part such as a pinky or a branch. So I think that you begin your argument with a flawed premise in that you don't define "human persons" as living animate material objects, things which can be said to either survive or not survive unlike that of inanimate matter, such as a rock wherein survival for it has no meaning.