An omnipotence principle from Aquinas

Aquinas believes that it follows from omnipotence that:

1. Any being that depends on creatures can be created by God without its depending on creatures.

But, plausibly:

2. If x and y are a couple z, then z depends on x and y.

3. If x and y are a couple z, then necessarily if z exists, z depends on x and y.

4. Jill and Joe Biden are a couple.

5. Jill and Joe Biden are creatures.

But this leads to a contradiction. By (4), we have a couple, call it “the Bidens”, consisting by Jill and Joe Biden, and by (2) that couple depends on Jill and Joe Biden. By (1) and (5), God can create the Bidens without either Jill or Joe Biden. But that contradicts (3).

So, Aquinas’ principle (1) implies that there are no couples. More generally, it implies that there are no beings that necessarily depend on other creatures. All our artifacts would be like that: they would depend on parts. Thus, Aquinas’ principle implies there are no artifacts.

Thomists are sometimes tempted to say that artifacts, heaps and the like are accidental beings. But the above argument shows that that won’t do. God’s power extends to all being, and whatever being creatures can bestow, God can bestow absent the creatures. If the accidental beings are beings, God can create them without their parts. But a universe with a heap and yet nothing heaped is absurd. So, I think, we need to deny the existence of accidental beings.

If we lean on (1) further, we get an argument for survivalism. Either Socrates depends on his body or not. If Socrates does not depend on his body, he can surely survive without his body after death. But if Socrates does depend on his body, then by (1) God can create Socrates disembodied, since Socrates’ body is a creature. But if God can create Socrates disembodied, surely God can sustain Socrates disembodied, and so Socrates can survive without his body. In fact, the argument does not apply merely to humans but to every embodied being: bacteria, trees and wolves can all survive death if God so pleases.

Things get even stranger once we get to the compositional structure of substances. Socrates presumably depends on his act of being. But Socrates’ act of being is itself a creature. Thus, by (1), God could create Socrates without creating Socrates’ act of being. Then Socrates would exist without having any existence.

I like the sound of (1), but the last conclusion seems disastrous. Perhaps, though, the lesson we get from this is that the esse of Socrates isn’t an entity? Or perhaps we need to reject (1)?

Ill-suited matter, form, and immortality

A question I haven’t seen explored much by contemporary neo-Aristotelian metaphysics is that of matter ill-suited to the form. Is it metaphysically possible for a bunch of molecules arranged like a normal oak tree to have the form of a pig? It would be, of course, a very unfortunate pig. Or is some minimal amount of match between the actual arrangement of the molecules and the form needed?

On light-weight neo-Aristotelianism, on which forms are simply structural properties, the answer has got to be negative.

But on heavy-weight neo-Aristotelianism, on which forms are irreducible entities, it seems like there should be no such restrictions. Why couldn’t God unite the form of a pig with a body as of an oak tree, or the form of an oak tree with a body as of a human?

However, supposing that we take such a liberal view on which there is no such thing as matter metaphysically incompatible with a form (presumably pace historical Aristotelians), we then have a puzzle. If it would be metaphysically possible for a pig form to be united to a bunch of organic gases, why is it that when pigs are vaporized, they (we assume) invariably die? Here is my story. Assume for simplicity time is discrete. At each time t, a pig—in virtue of its form—has a causal power to continue existing at the next time. But causal powers have activation conditions. The activation condition for the causal power to continue existing at the next time is an appropriate arrangement of the pig’s body. When the pig’s body becomes so distorted that this activation condition is no longer satisfies, the pig loses the power to go on living. And so it dies. However, of course, God could make it keep on living by a miracle: a miracle can supply what the causal powers of a thing are incapable of.

This account has one somewhat implausible prediction. Suppose that some powerful being instantaneously scatters the molecules of an ordinary pig across the galaxy, so that at t₁ we have an ordinary pig and at the next time, t₂, the pig molecules are scattered. Because at t₁ the pig has a causal power of continuing to exist conditionally on its molecules being appropriately arranged at t₁, and this condition is indeed satisfies at t₁, the pig will live one moment in scattered condition at t₂—and then perish at the next moment, t₃.

On this account, external causes do not directly destroy an object. Rather, they destroy the activation condition for the object’s power to continue existing. When that activation condition is destroyed, the object (barring a miracle) ceases to exist. But it has that one last existential hurrah before it falls into nonbeing.

Does it follow that on a heavy-weight Aristotelianism with my story about death, a pig metaphysically could survive the annihilation of its body? I am not sure, but I am inclined to think so. Indeed, I am inclined to think that if we had a normal pig at t₁, and then at t₂ the matter of the pig were annihilated, the pig would still exist—reduced to an abnormal immateriality—for that one instant of t₂, and then, barring a second miracle, it would slide into non-being at t₃.

What about us? Well, Aquinas argues for our soul’s natural immortality on the grounds that the human soul has a proper operation that does not depend on the matter, namely pure thought. I have never before been impressed by the move from a proper operation independent of matter to natural immortality, but in my above (neo-Aristotelian but not very Thomistic) setting I see it having significant force. First, we have this question: What are the activation conditions for the human’s power-to-continue-existing? It makes sense that for a being whose only non-existential operations are material, the activation conditions should be purely material. But if a being has a proper operation not dependent on the matter, then it makes perfect sense for the activation conditions of its power-to-continue-existing not to include material conditions. In fact, something stronger can be said. It seems absurd for a thing to have a power to continue thinking whose activation conditions outstrip its power to continue existing. It would be like a power to play soccer without a power to move. So, it seems, if Aquinas is right that we have an immaterial operation, then we have the power to continue existing even absent a body. Of course, God can stop cooperating with any power we have, and if he stopped cooperating with our power-to-continue-existing, then we would stop existing (unless God miraculously sustained us in existence independently of that power!), but naturally we would continue to exist. Assuming, of course, Thomas is right about us having a proper operation that does not depend on matter, which is a different question.

(And unlike Thomas, I think we have immortality, not just our souls.)

Aquinas and Descartes on substance dualism

Roughly, Aquinas thinks of a substance as something that:

1. is existentially independent of other things, and

2. is complete in its nature.

There is a fair amount of work needed to spell out the details of 1 and 2, and that goes beyond my exegetical capacities. But my interest is in structural points. Things that satisfy (1), Aquinas calls “subsistent beings”. Thus, all substances are subsistent beings, but the converse is not true, because Aquinas thinks the rational soul is a subsistent being and not a substance.

Descartes, on the other hand, understands substance solely in terms of (1).

Now, historically, it seems to be Descartes and not Thomas who set the agenda for discussions of the view called “substance dualism”. Thus, it seems more accurate to think of substance dualists as holding to a duality of substance in Descartes’ sense of substance than in Aquinas’.

But if we translate this to Thomistic vocabulary, then it seems we get:

3. A “substance dualist” in the modern sense of the term is someone who thinks there are two subsistent beings in the human being.

And now it looks like Aquinas himself is a substance dualist in this sense. For Aquinas thinks that there are two subsistent beings in Socrates: one of them is Socrates (who is a substance in the Thomistic sense of the word) and the other is Socrates’ soul (which is a merely subsistent being). To make it sound even more like substance dualism, note that Thomas thinks that Socrates is an animal and animals are bodies (as I have learned from Christopher Tomaszewski, there are two senses of body: one is for the material substance as a whole and the other is for the matter; it is body in the sense of the material substance that Socrates is, not body in the sense of matter). Thus, one of these subsistent beings or substances-in-the-Cartesian-sense is a body and the other is a soul, just as on standard Cartesian substance dualism.

But of course there are glaring difference between Aquinas’ dualism and typical modern substance dualisms. First, and most glaringly, one of the two subsistent beings or Cartesian substances on Aquinas’s view is a part of the other: the soul is a part of the human substance. On all the modern substance dualisms I know of, neither substance is a part of the other. Second, of the two subsistent beings or Cartesian substances, it is the body (i.e., the material substance) that Aquinas identifies Socrates with. Aquinas is explicit that we are not souls. Third, for Aquinas the body depends for its existence on the soul—when the soul departs from the body, the body (as body, though perhaps not as matter) perishes (while on the other hand, the soul depends on the matter for its identity).

Now, let’s move to Descartes. Descartes’ substance dualism is widely criticized by Thomists. But when Thomists criticize Descartes for holding to a duality of substances, there is a danger that they are understanding substance in the Thomistic sense. For, as we saw, if we understand substance in the Cartesian sense, then Aquinas himself believes in a duality of substances (but with important structural differences). Does Descartes think there is a duality of substances in the Thomistic sense? That is not clear to me, and may depend on fine details of exactly how the completeness in nature (condition (2) above) is understood. It seems at least in principle open to Descartes to think that the soul is incomplete in its nature without the body or that the body is incomplete in its nature without the soul (the pineal gland absent the soul sure sounds incomplete) or that each is incomplete without the other.

So, here is where we are at this point: When discussing Aquinas, Descartes and substance dualism we need to be very careful whether we understand substance in the Thomistic or the Cartesian sense. If we take the Cartesian sense, both thinkers are substance dualists. If we take the Thomistic sense, Aquinas clearly is not, but it is also not clear that Descartes is. There are really important and obvious structural differences between Thomas and Descartes here, but they should not be seen as differences in the number of substances.

And here is a final exegetical remark about Aquinas. Aquinas’ account of the human soul seems carefully engineered to make the soul be the sort of thing—namely, a subsistent being—that can non-miraculously survive in the absence of the substance—the human being—that it is normally a part of. This makes it exegetically probable that Aquinas believed that the soul does in fact survive in the absence of the human being after death. And thus we have some indirect evidence that, in contemporary terminology, Aquinas is a corruptionist: that he thinks we do not survive death though our souls do (but we come back into existence at the resurrection). For if he weren’t a corruptionist, his ontology of the soul would be needlessly complex, since the soul would not need to survive without a human being if the human being survived death.

And indeed, I think Aquinas’s ontology is needlessly complex. It is simpler to have the soul not be a subsistent being. This makes the soul incapable of surviving death in the absence of the human being. And that makes for a better view of the afterlife—the human being survives the loss of the matter, and the soul survives but only as part of the human being.

Two interaction problems

Yesterday I realized something that should have been obvious: there are two separate interaction problems for dualism.

1. Metaphysics: How does the soul manage to cause effects in the body?

2. Physics: Wouldn’t such causation violate the laws of physics?

I used to think of the interaction problem as just (1), and hence I thought it was spurious once one learned from Hume that all cases of causation are equally mysterious.

But problems (1) and (2) are pretty independent: one can have a solution to each without a solution to the other. For instance, an indeterministic physics provides a solution to (2), but says nothing about (1), while occasionalism and hylomorphism provide solutions to (1), but say little about (2).

While I think the questions are interesting, I don’t really think either poses a serious problem for interactionist dualism.

A fun unsound argument for dualism

Here’s a fun argument for dualism.

1. What is a part of the body is a matter of social convention.

2. Persons are explanatorily prior to social conventions.

3. So, probably, persons are not bodies.

I think (2) is undeniable. And (1) is a not uncommon view among people thinking about prostheses, implants, transplants and the like.

That said, I think (1) is just false.

Disembodied trees

Here’s an interesting thesis:

1. If x has the ys among its parts, and for each z among the ys, x can survive losing z without gaining anything, then x can survive simultaneously losing all the ys without gaining anything.

There are obvious apparent counterexamples. A boat that has sufficient redundancy can survive the loss of any plank, but cannot survive losing them all. An oak tree can lose any cell but cannot lose all cells.

But counterexamples aside, wouldn’t (1) be a nice metaphysical thesis to have? Then essential parts wouldn’t be made of inessential ones. You can see all the nasty ship-of-Theseus questions that would disappear if we had (1).

I think an Aristotelian can embrace (1), and can get around the counterexamples by biting some big bullets. First, like some contemporary Aristotelians, she can deny that artifacts like boats (or bullets) exist. Second, she can say that oak trees can survive the loss of all their matter, becoming constituted by form alone, much as some philosophers say happens to human beings after death (before the resurrection). The second part seems a bigger bullet to bite, as one would need a story as to why in fact oak trees perish when they lose all their cells, even if they don’t have to. But perhaps that’s just contingently how it happens, though an all powerful being could make an oak tree survive the destruction of all its cells.

The big question here is exactly what philosophical advantages embracing (1) has.

Immaterial body parts

Here’s a difficult question: Does an artificial heart literally become a body part of the patient?

And here’s a line of thought suggestive of a negative answer.

1. Necessarily, all our body parts are material.

2. If one could have an artificial heart as a body part, one could have an immaterial artificial heart as a body part.

3. So, one cannot have an artificial heart as a body part.

Why accept 2? Because presumably what makes an artificial heart suitable for being a body part is that it does the job of a heart. But we could imagine an immaterial being which does the job of a heart. For instance, an angel could move blood around the body, and do so in response to electrical activity in the brain stem. Perhaps one could say that an angel couldn't be a body part, because it is already an intelligent being. But we could then imagine something that moves blood around like the angel but doesn’t have a mind.

I am not so confident of premise 1, however. One could, I suppose, turn the argument around: An artificial heart could be a body part, so possibly some of our body parts are immaterial. And if that’s right, then given a view on which body parts are informed by the form of the person, we would have the further interesting conclusion that a form can inform something that isn’t matter.

Rapid cell replacement: A failed argument against materialism

I thought I had a nice argument against materialism, but it didn’t work out. Still, it’s fun to think about the argument and why it doesn’t work.

Start with this plausible thesis, which seems at least naturally necessary:

1. If any cell in a human body blinks out of existence and a new cell, exactly like the one before, blinks into existence sufficiently quickly in the same orientation, then the result would not interrupt the human’s life or any train of consciousness.

Now imagine that very, very quickly one-by-one every cell in my body blinks out of existence and is replaced by a new cell formed by a coincidental quantum fluctuation. Moreover, suppose each replacement happens sufficiently quickly in the sense of (1), and indeed so quickly that all of the replacements are done in less than the blink of an eye. Applying claim (1) billions of times, I conclude that neither my existence nor my train of consciousness would be interrupted by this process.

But if materialism is true, the resulting entity would have insufficient causal connection to me to be me. Thus, if materialism is true, I would have to cease to exist as a result of these rapid replacements. But it seems this would violate (1) at some point. (Moreover, the resulting being would not be the product of natural selection, so on evolutionary functionalist theories, the being would not have mental states. Furthermore, in any case, its brain states would not have the kinds of connections with the external world that give rise to content according to the best materialist theories, so its thoughts would be largely contentless.)

But the argument I just gave doesn’t work. First, (1) is false in the case of a human zygote, since the destruction of one’s only cell would kill one. What made (1) plausible was the thought that we had many cells, and the replacement of any one of them with a randomly produced cell would make no difference. So, (1) needs to be modified to remain plausible:

2. If any cell in a human body consisting of many cells blinks out of existence and a new cell, exactly like the one before, blinks into existence sufficiently quickly in the same orientation, then the result would not interrupt the human’s life or any train of consciousness.

But now it no longer follows that a quick cell-by-cell replacement would have to keep me alive. For here is a possible hypothesis: For a replacement cell to come to be a part of the body, it has to come to be sufficiently causally intertwined with the rest of the body. This takes some time. It could well be that if the cells are replaced one by one in less than the blink of an eye, the new cells don’t have time to become intertwined with the rest of the body. Thus, the body comes to have fewer and fewer cells as the gradual replacement process continues. If the replacement process were to stop, pretty quickly the replacement cells would come to be causally intertwined with the veteran cells, and would come to be a part of the body. But it doesn’t stop. As a result, eventually the process leads to a state where I don’t have “many” cells in my body, and hence (2) becomes inapplicable.

What if, on the other hand, the replacement is done more slowly, so that there is time for cells to causally intertwine and become a part of the body? Then there need be no problem for materialism, because now the resulting entity does have a sufficient causal connection to me to be me.

There is, of course, a vagueness problem for the materialist: When do I cease to exist in the process? But that's another argument. I think typical materialists who think that they exist cannot escape vague existence.

Does Christianity require a belief in matter?

The doctrines of incarnation, resurrection and real presence certainly require us to believe ordinary language existence claims about bodies, bread and wine. It's hard to take Scripture to be inspired without believing ordinary language existence claims about plants, animals, mountains, seas, etc. But do we need to believe that there is matter?

A search of the Church Councils up to and including the First Vatican Council turns up nothing dogmatic about "matter" in the relevant sense of the word (I am not including the technical sense of "matter of a sacrament" in sacramental theology). Searching for "material" finds some talk of material weapons, material flesh, and material food and drink. But I think that it would seem to me to be an overreach to take the Councils to be dogmatically teaching that weapons, flesh and food and drink are material. Rather, the relevant distinction seems to be between the spiritual weapons, spiritual flesh and spiritual food and drink and their ordinary earthly versions, rather than teach something about the nature of the ordinary versions, except that they differ from the spiritual.

I used to think that we need to believe hylomorphism. After all, the Fifth Lateran Council teaches that the soul is the form of the body. But while this gives us the morphê (form) part of hylomorphism, it doesn't give use the hyle (matter) part. We need to believe that the soul is the form of the body; not that it is the form of the matter.

If this reading of the Tradition is right, then Christian philosophers do not need to try to figure out the knotty question of what constitutes materiality. We have to accept, in some way, the existence of bodies, bread and wine, but we don't have to say that these things fall into some philosophically important kind like "matter". The handful of statements about "material" things we can simply understand in the vague way as about "things relevantly like ordinary things around us", without thinking that matter is any kind of metaphysically or physically important kind. We don't have to worry that if it turns out on our best science that physical reality is constituted by fields rather than particles, then we will have a conflict between faith and science. We still would have to find a way of locating bodies, bread and wine within physical reality, but we would not have to identify them with bits of matter.

Of course, it may turn out that the concept of matter has philosophical or scientific use apart from the needs of faith. But I have a suspicion that thinking about the nature of the body may be more promising than thinking about the nature of matter.

Soul-body interaction

I have a post on soul-body interaction on Biola's Center for Christian Thought blog that may be of interest to my readers here.

Belonging and members

In Ephesians 4:25, Paul talks of us Christians being all members of one another. Karol Wojtyla thought of romantic love as directed at mutual possession (I am grateful to John Crosby for pointing this out). Plausibly, this possession is not like ownership, but more like the body parts are related to the person they belong to.

A sensible reading of these and other texts requires a non-authoritarian view of the relations between ourselves and our body parts, a view on which our authority over our body parts is limited. This has serious repercussions for things like sterilization, gender-reassignment surgery and more radical forms of elective cosmetic surgery.

Remembering your body

Suppose that as I slept, my body has been switched on me in the middle of the night, but all my memories were kept intact. Now it's morning and I have woken up in a new body. But the new body is similar enough to the old that I haven't noticed any difference. My, will I be surprised when I look in the mirror.

I remember going to bed last night. Or do I?

In remembering going to bed, what do I remember? I remember, perhaps, my feeling myself lying bodily in bed. That involves remembering my body as lying in bed.

Which body do I remember lying in bed?

Consider: I remember my body as lying in bed a few seconds ago and I remember my body as lying in bed the previous morning Moreover, there seems to be a univocity to these memories. It is the same body that I remember lying in bed, just as it is the same bed that I remember it lying in. I have no idea that today's body is different from yesterday's body.

Suppose the body I remember lying in bed is yesterday's body in both cases. Then my memeories from a few seconds ago are non-veridical when I remember my body being in bed a few seconds ago. And that doesn't seem right.

Suppose the body I remember lying in bed is today's body in both cases. Then I don't actually remember my body lying in bed yesterday morning: it was a different body that was lying in bed. I am misremembering due to an error of body misidentification.

But if I am misremembering, then my memories must have somehow changed. Last night my memories of yesterday morning were veridical. So at night they must have changed, either in type or in token.

And so the initial description of the story was wrong: I didn't actually switch bodies while keeping all my memories intact.

But perhaps I am wrong when I insist that the body I remember lying in bed a few seconds ago is the same body I remember lying in bed yesterday morning. Perhaps bodies are like clothes: when I remember wearing a blue shirt yesterday and I remember wearing a blue shirt a week ago, there is no particular blue shirt that I remember wearing on both occasions. I just remember wearing some blue shirt or other. Likewise, maybe rather than remembering a particular body as lying in bed yesterday morning, I remember lying in bed yesterday morning in some body or other, and I remember lying in bed this moring in some body or other.

I am not sure that's right. Surely I can remember that yesterday morning I had my phone in this hand, checking my email while awaiting the full return of consciousness. And so there is a particular hand in my memories, the same one that I remember holding my phone in a few seconds ago. And, again, as before this is either yesterday's hand or today's hand. That it's yesterday's hand means that I can't remember which hand I held the phone in a few seocnds ago. That it's today's hand means that I must have lost a memory.

But let's press on this. Can't the same thing happen with clothes? Say I remember wearing this very shirt last week, the one I am wearing now. But suppose my wife has switched it on me in the meanwhile. Surely a switch of shirts doesn't imply a loss of memory. But which memory is mistaken? My memory of wearing this shirt last week or my memory of wearing it now? Neither, perhaps. I remember wearing this shirt a few seconds ago. I remember wearing that shirt last week. But I don't remember wearing this shirt last week—though I may say I do. What I remember is wearing a shirt like this.

Can I make the same move with hands? I don't remember holding the phone in this hand. I simply remember holding the phone in a hand like this—most notably, like it in respect of chirality and connection to my mind. Still, I think it gets the phenomenology wrong.

So, if I'm right, the hypothesis of changing bodies while keeping all memories is a dubious one. Our autobiographical memories are bound up with our bodies—just as we enter de re into our autobiographical memories, so do our bodies.

Could I, though, switch bodies and keep a core of autobiographical memories? I am not sure. Core autobiographical memories seem to be closely bound up with embodiment. We can abstract from the particulars of embodiment, but when we abstract from a memory what we get need not be a memory any more. I remember lying in bed last night in some body or other, I say. But that's an abstraction from what I actually remember, perhaps—I remember lying on my back—this back—with a pressure sensation in my hand—this hand—from the phone that I am holding in it while checking my email. That's the memory.

Is this fatal to psychological theories of personal identity? Maybe not: maybe only to ones that are focused on autobiographical memories.

I am not entirely convinced by this argument, but I think it has some force.

A fun argument for dualism

I'm told that a version of the following argument is somewhere in C.S. Lewis:

1. (Premise) Our embodiment is universally seen as funny.
2. (Premise, justified inductively by 1) Our embodiment is objectively funny.
3. (Premise) The essence of the funny is incongruity.
4. (Premise) If materialism is true, there is no incongruity in our embodiment.
5. (Premise) If materialism is false, then dualism is true.
6. There is incongruity in our embodiment. (2 and 3)
7. Materialism is false. (4 and 6)
8. Dualism is true. (5 and 7)

Using body parts and other natural human systems

While I'm inclined to agree that

1. it's wrong to use a natural human system (body part, aspect of the soul, naturally grounded activity, etc.) contrary to one of its natural purposes,

I am less sure about the stronger thesis that

2. it's wrong to use a natural human system in a way that isn't contrary to any of its natural purposes, but is also not in accord with any of its natural purposes.

I've been thinking about (2) today, and thought of an argument in favor of it. The human person is a closely unified whole (I actually do not think the human person has any actual proper parts). To use a part is to use the whole in respect of that system. Likewise, the telos of the system is a telos of the whole in respect of that system. Thus, to use one's system in a way that is not in accord with any telos that it has is to use oneself as a mere means, unless somehow one can create a new telos for one's own natural systems. Therefore if we keep the Kantian thesis that we shouldn't use ourselves as mere means, and supplement it with the metaphysical thesis that we cannot create a new telos for a natural system (this thesis seems anti-Kantian in spirit, but I think the historical Kant might well be friendly to it, given the Natural Law components in his ethics—say, his discussion of euthanasia or the solitary vice), we have an argument for (2). This would be a Kantian theory with a significant injection of Natural Law. Perhaps this kind of injection of Natural Law also helps with the problem of Kantianism being too formal to apply to concrete situations.

I wonder if (2) could be defended in the case of non-human natural systems. On the face of it, not: after all, it's perfectly acceptable to ride a horse, and carrying a burden doesn't seem to be a natural telos of its back. But I am inclined to think that it may be a telos of every non-human living creature on earth to serve human beings (maybe with some proportionality constraint built in). That may be why we may kill and eat at least some of them (it's uncontroversial that we may kill and eat edible plants and fungi). If this is right, then if one uses an animal for a purpose that is not a good, say by riding out on a horse to an unjust war, one not only does wrong by pursuing something that isn't a good, but one also does wrong by misusing the animal.

Why do we need bodies?

The following scenario is adapted from Keith Laumer's story "The Body Builders": Technology reaches the point that our brains, while still in our natural bodies, can be remotely connected to a synthetic body, which would be as manipulable and would provide as much and as good sensory input as our real bodies. The natural bodies, with brains in their skulls, can be kept in municipal storage, where they will be carefully maintained, exercised and kept trim and healthy, without us being aware of it, because the sensory connections between the brain and the rest of the natural body are severed. It seems the synthetic body could do all the tasks that the natural body could, but would provide two advantages: (a) it could technologically improve on the capabilities of the natural body, say, by providing more strength, agility or sensory data, and (b) one will avoid danger, since one's brain and natural body are safe in municipal storage while the synthetic body goes out into the world of whizzing cars, disease, and all that. Very quickly, one starts to feel about the synthetic body as if one were there, in it—as if it were one's own body.

Question: In a scenario like this, what would we lose? What couldn't we do in this scenario if we did everything through the synthetic body?

One class of activities that we would lose out on are various hobby and sport activities where the contingent limitations of our bodies are important. If various drugs are contrary to good sportsmanship (though, on the other hand, consider the case of Oscar Pistorius), obviously this will be. There can be sports that are played with synthetic bodies. They would in some way akin to remote control car racing. But they would, indisputably, be essentially different sports from the ones we have. (That's part of the point of the Laumer story.)

A second class of acitvities that we would lose out on are ones where physical danger appears to be central to meaning of the activity. Climbing Mt. Everest is a paradigm example. I am inclined to think activities where danger is courted are contrary to the virtue of prudence, since danger is a bad thing. If one could climb Mt. Everest while ensuring safety (e.g., by having a button which, if pressed, would teleport one to a medical facility), one should.

But both of the above classes of activities are pretty much optional to human life. We could get along pretty much fine without bodily sports or mountain climbing: we could still have video games, and cases where non-physical courage is exercised. We would lose out, but we would not lose out on all that much.

In thinking about this, the only cases of activities crucial to the good of humanity that I can think of which could not be done through the synthetic bodies would be:

1. Basic survival functions. (Those would need to be done in municipal storage.)
2. (a) Sexual union and (b) reproduction.
3. The sacraments of baptism, confirmation, Eucharist, ordination and annointing of the sick.

One might think (2a) could be done remotely, and (2b) could be done technologically in municipal storage (extracting sperm and egg, combining them, etc.) But this is mistaken. Sexual union is essentially embodied: the remote "union" would only illusorily be a physical union. And doing (2b) apart from (2a) is immoral—human beings should be the fruit of marital union.

It's interesting that apart from basic survival functions, all of the activities that are both crucial to the good of humanity and that require the natural body are sacraments or closely tied to sacraments ((2) is obviously closely tied to the sacrament of matrimony, as its consummation). It's also interesting that two sacraments are left off the list in (3): reconciliation and matrimony. While currently reconciliation is normally done through in-person confession, I do not think this is essential to the sacrament—I think the Church could change this (I am not saying it would be wise to change it) to confession, say, by telephone. (If general absolution is valid, remote absolution would probably be valid, too, if the Church allowed it.) And while matrimony essentially requires the exchange of consent, this consent need not be given in spoken words (Canon 1104.2), and it is permissible for the two parties to be present only by proxy (Canons 1104.1 and 1105). Still, the consummation must be happen in person for the marriage to be indissoluble.

That, apart from basic survival, all the most important non-survival functions for which a natural body is essential are religious ones or closely tied to religious ones neatly refutes the popular idea that the Christian Church thinks poorly of the human body.

The importance of the body

While my philosophical views attach a great deal of importance to the body, my feeelings often do not go along with that. I used to be a Cartesian, and I still have a hard time thinking of myself as this enmattered six-foot-tall entity.

That was why I was particularly struck by Episode 3.24 of Star Trek, now legally available online (at least in the US), along with the rest of the original three series. There, Dr. Janice Lester switches bodies with Captain Kirk, for revenge and in order to achieve her ambitions. What I found striking was how hard it was for me to feel that the person inhabiting Lester's body was Kirk and the person inhabiting Kirk's body was Lester. The best I could really do was to feel that the person inhabiting Lester's body was someone other than Lester (but not necessarily Kirk), and the person inhabiting Kirk's body was someone other than Kirk, in light of the severe personality changes. (A complicating factor is that Lester pretends to actually be Kirk. But that only mixes up one of the two.)

The body does matter. Wittgenstein is right: "The human body is the best picture of the human soul."