A problem for Van Inwagen's life condition for composition

Van Inwagen thinks that a plurality of xs composes something if and only if either there is only one thing among the xs or the xs have a life together.

He also agrees that the fundamental particles making up a cell in a multicellural organism have a life together, and so there are cells.

Here is a problem. The following seem true:

1. It is possible to have two overlapping cells in a multicellular organism neither of which is a part of the other.

2. The cells of a multicellular organism together with any intercellular fundamental particles have a life together.

Why think (1)? Because, first, conjoint twins show that multicellular organisms can have “proper overlap”: i.e., they have a part in common but neither is a part of the other, and it seems hard to deny that cells, too, could in principle be like that. Second, it seems plausible that mid-way through a process of mitosis we have two cells that properly overlap.

It seems hard to deny (2), assuming there are cells.

But now consider a multicellular organism which happens to have two overlapping cells. Its cells, together with any intercellular fundamental particles, have a life together. Hence, by van Inwagen’s famous account of composition, the cells and the intercellular fundamental particles compose something. But van Inwagen’s definition of composition includes a no-overlap condition: if the xs compose y, no two xs overlap. And yet in our case we have life and overlap.

What should van Inwagen do? One move would be to weaken the Special Composition Question. Instead of asking when the xs compose something, he could ask when non-overlapping xs compose something. But that makes his view rather less informative than we might think, if overlap between cells is fairly common. Presumably in a body of my size, at any given time, mitosis is occuring in a number of cells (I haven’t done the math, but it seems likely).

Does it follow from van Inwagen's answer to the Special Composition Question that all complex things are alive?

The view that all objects are either living or simple appears to be a consequence of van Inwagen’s answer to the special composition question, namely that a proper plurality only composes a whole when the parts have a life together, where a proper plurality is a plurality of two or more things.

But this does not follow. Van Inwagen defines:

1. The xs compose y if and only if “the xs are all parts of y and no two of the xs overlap and every part of y overlaps at least one of the xs”.

Now the view that all non-simples are alive follows from van Inwagen’s answer to the special composition question (SCQ) provided that we have to have:

2. Anything that has proper parts is composed of some proper plurality of its proper parts.

3. Whenever something is composed of a plurality of things that have a life together, it is alive.

Indeed, if we have 2 and 3, then anything that has proper parts is composed of proper plurality by 2, which thus have a life together by van Inwagen’s answer to SCQ, and hence the thing composed of them is alive by 3. On the other hand, if there can be something that has proper parts but isn’t composed of a proper plurality of proper parts, then there is no way to use van Inwagen’s answer to SCQ to argue that it’s alive. Furthermore, if there is something that is composed of a proper plurality of proper parts that have a life together but isn’t alive, then we have another counterexample to van Inwagen.

Neither 2 nor 3 is completely obvious. You might, for instance, think that where you are, there is also a heap of atoms shaped just like you. If, further, you are a presentist and a materialist, you will think the atoms compose you and compose the heap. Moreover, the atoms have a life together. But the heap of atoms is not alive, unlike you. So (3) on that view is false.

For a view on which (2) is false, imagine a world consisting of four objects, A, B, C and D. Object A has B, C and D as proper parts. Object B has D as a proper part. Object C has D as a proper part. There are no other instances of proper parthood. This is a world where the company axiom of mereology fails (since B and C have D as a proper part and no other proper parts). It would be interesting to characterize in some non-trivial way the mereological theories where (2) is true. A sufficient condition is to assume atomism (Gemini Pro noted this). We can define this by saying every object has a simple part. For then if an object has a proper part, it is easily seen to be composed by its proper parts. But atomism is not a necessary condition. Consider a gunky mereological model whose domain is infinite sets of natural numbers and parthood is inclusion—then (2) is true.

We could also escape this worry by weakening the definition of composition by dropping the requirement that no two of the xs overlap. That makes van Inwagen’s answer to the SCQ put a more stringer requirement on reality, and it becomes trivial that everything that has proper parts is composed of them, and (2) becomes a matter of logic. We still need an argument for (3), however.

The five-five trolley

The standard trolley case is where a trolley is heading to a track with five people, and you can redirect it to a track with one person. It seems permissible to do so.

But now imagine that a trolley is heading to a track with five people, and you can redirect it to another track also with five people. Why would you bother? Well, suppose that you enjoy turning the steering wheel on the trolley, and you reason that there is no overall harm in your redirecting the trolley.

This seems callous.

Yet we are in cases like the five-five trolley all the time. By the butterfly effect, many minor actions of ours affect the timings of human mating (you have a short conversation with someone as they are leaving work; this affects traffic patterns, and changes the timing of sexual acts for a number of people in the traffic), which then changes which sperm reaches an ovum, and hence affects which human beings exist in the next generation, and the changes balloon, and pretty soon there are major differences as to who is in the path of a hurricane, and so on.

But of course there is still a difference between the five-five trolley and the butterfly effect cases. In the five-five trolley, you know some of the details of the effects of your action: you know that these five will die if you don’t redirect and those five if you do. But note that these details are not much. You still may not know any of the ten people from Adam. In the butterfly effect cases, you can say a fair amount about the sort of effects your minor action has, but not much more than that.

What’s going on? I am inclined to think that here we should invoke something about the symbolic meaning of one’s actions. In the case where one turns the steering wheel on the trolley for fun, while knowing epistemically close effects, one exhibits a callous disregard for the sanctity of human life. But when one has a conversation with someone after work, given the epistemic distance, one does not exhibit the same callous disregard.

It is not surprising if callousness and regard for sacredness should depend on fine details of epistemic and other distance. Think of the phenomenon of jokes that come “too soon” after a terrible event: they show a callous disregard for evil. But similar jokes about temporally, personally and/or epistemically distant events may be acceptable.

Life, simulations and AI

1. An amoeba is alive but an accurate simulation of an amoeba wouldn’t be alive.

2. If (1), then an accurate simulation of a human wouldn’t be alive.

3. So, an accurate simulation of a human wouldn’t be alive.

4. Something that isn’t alive wouldn’t think.

5. So, an accurate simulation of a human wouldn’t think.

6. If an accurate simulation of a human wouldn’t think, Strong AI is false.

7. Strong AI is false.

Behind (2) is the idea that the best explanation of (1) is that computer simulations of living things aren’t alive. I think (4) is perhaps the most controversial of the premises.

Megavalue

In my previous post, I glibly talked of the infinite value of persons. I forgot that such talk was discredited by this argument. Instead, one should talk of relatively infinite value: being infinitely more times valuable than.

I think the argument of that post can be rescued. And while I am at it, I can modify the argument to avoid another objection, that higher animals like dogs and dolphins are not infinitely less valuable than persons. I do not know if the objection is sound, but it won't matter.

1. Definition: A thing has megavalue if and only if it is infinitely more times valuable than every portion of non-living reality in the universe.

2. The sum total of life in the universe has megavalue.

3. Nothing can cause something that has infinitely more value than itself.

4. If the sum total of life in the universe has a cause and that cause is wholly within the universe, then the cause is a portion of the non-living reality in the universe.

5. There is a cause of the sum total of life in the universe.

6. A cause of the sum total of life in the universe is not wholly within the universe.

Yet another account of life

I think a really interesting philosophical question is the definition of life. Standard biological accounts fail to work for God and angels.

Here is a suggestion:

• x has life if and only if it has a well-being.

For living things, one can talk meaningfully of how well or poorly off they are. And that’s what makes them be living.

I think this is a simple and attractive account. I don’t like it myself, because I am inclined to think that everything has a well-being—even fundamental particles. But for those who do not have such a crazy view, I think it is an attractively simple solution to a deep philosophical puzzle.

The General Composition Question

Peter van Inwagen distinguishes the General Composition Question (GCQ), which is to give necessary and sufficient conditions for the claim that the xs compose y without mereological vocabulary, from the Special Composition Question (SCQ), which is to give non-mereological necessary and sufficient conditions for the claim that there is a y such that the xs compose y again without mereological vocabulary. He thinks that he can answer the SCQ as:

1. The xs compose something iff there is exactly one x or the activity of the xs constitutes a life.

But he doesn’t try to give an answer to the GCQ, and suspects an answer can’t be given.

It is now seeming to me that van Inwagen should give a parallel answer to GCQ as well:

2. The x compose y iff the xs compose* y.

3. The xs compose* y iff every one of the xs is a part* of y and everything that overlaps* y overlaps* at least one of the xs.

4. x overlaps* y iff x and y have a part* in common.

5. x is a part* of y iff x = y or x’s activity constitutes engagement in the life of y.

Here, (3) and (4) mirror the standard mereological definition of composition and overlap, but with asterisks added. The asterisked concepts, however, bottom out in non-mereological concepts.

One might worry that constitution is a mereological concept. But if it is, then van Inwagen’s answer to the SCQ is also unsatisfactory because it uses constitution.

I feel that (2)–(5) might have some simple counterexample, but I can’t see one (or at least not one that isn't also a counterexample to van Inwagen's answer to the SCQ).

By the way, there is a cheekier answer to the GCQ:

6. The xs compose y iff the xs and y satisfy the predicate “composes” of the actual world’s late 20th century philosophical English language.

Note that here the response does not make any use of mereological vocabulary, since “‘composes’” (unlike “composes”) is not a piece of mereological vocabulary, but a piece of metalinguistic vocabulary.

A technical problem for organicism

Van Inwagen’s account of composition is that

1. the xs compose a whole if and only if their activity constitutes a life.

Here is a possible problem that just occurred to me. Let x₁ be me and let x₂ be one of my particles. Then x₁ and x₂ compose me.

Now when a plurality of things have an activity, that activity is a joint activity. However, just as it is ridiculous to say that I and my right leg have walking as a joint activity, it seems incorrect to say that I and my particle have a joint activity that constitutes a life. Thus, it seems incorrect to say that x₁ and x₂ have an activity that constitutes a life. Of course, x₁ by itself has an activity ϕ that constitutes a life, and x₂ participates in ϕ. But given that ϕ is the activity of x₁ by itself, it seems incorrect to say that ϕ is a joint activity of x₁ and x₂.

One might try to define a more technical concept of engaging in an activity that implies that whenever x₁ engages in an activity ϕ with the help of a part x₂, that always counts as x₁ and x₂ engaging in ϕ. Here is an attempt:

2. The xs engage in an activity ϕ if and only if each of the xs contributes to ϕ and together they accomplish all of ϕ.

But it seems wrong to say that I and my particle x₂ together accomplish a life. That would once again sound like we have a joint activity, which we don’t.

This is better:

3. The xs engage in an activity ϕ if and only if each of the xs contributes to ϕ and anything that is a part of something that contributes to ϕ overlaps one of the xs.

But this falls afoul of van Inwagen’s requirement that an answer to the special composition question make no reference to mereological concepts like parthood or overlap.

But perhaps I am needlessly fastidious about the use of language. Maybe I and my heart, or I and my topmost particle, do engage in life. We do sometimes use this locution about a government body: "x, with y at the helm, ϕed." Maybe if that's true, we can say that "x and y ϕed", despite y being a part of x. But it still sounds wrong.

Van Inwagen's ear

Van Inwagen holds that:

1. All and only things whose activity constitutes a life (properly) compose a whole.

2. Whether a plurality of things composes a whole depends only on their internal relations.

He considers a counterexample to (1) and (2) of the following sort. Let the xs be the particles in van Inwagen outside the right ear.

3. If van Inwagen were to have lost the right ear, the activity of the xs would have constituted a life (his life) and composed a whole (namely, van Inwagen).

4. But in fact, the activity of the xs does not constitute a life, but only partly does so, along with the activity of the right ear particles.

5. However, the internal relations between the xs were he to have lost his right ear would have been the same as they are now.

This is a problem: for by (4) and (1), the xs do not compose a whole, but by (3) they would have had he lost his right ear, and by (5) they would have had the same internal relations then, which contradicts (2).

Van Inwagen attempts to escape this problem by denying (5), saying that the internal relations between the particles in his body in the vicinity of the right ear would be affected by the ear not being there. For they would no longer experience forces from the ear particles.

But let d be the closest distance between a right-ear particle and a van Inwagen particle not in the right ear (i.e., one of the xs). But now if God were to suddenly annihilate the right ear, then it seems that none of the xs would be in any way affected until influences traveling at the speed of light could bridge the distance d. I.e., until d/c (where c is the speed of light) had passed, the xs would be without the ear just as they are with the ear. Hence, if we specify that the time of severance in (3) is less than d/c ago, van Inwagen’s response seems to fail.

One might try to get out of this by invoking (non-Bohmian) quantum mechanics, and saying that all particles have fuzzy positions, and the ear particles overlap positionally with the non-ear particles, so that the disappearance of the ear particles affects the non-ear particles instantly. But the instant part of the effect is slight. We can imagine that the disappearance of the ear is so orchestrated as to never split any molecules or atoms. But particles in different molecules are fairly localized to their respective molecules, and the effect of the tails of the wavefunction on what is going on in a neighboring molecule will presumably be negligible.

Of course, a negligible effect is still an effect. But we could imagine a third scenario: van Inwagen loses his ear, and God miraculously tweaks the movements of the xs in a slight and biologically negligible way during the d/c period so that they behave just as they do in the actual world where the ear is attached. In that scenario, the xs would compose van Inwagen, but they would have exactly the same internal relations as they do in the actual world.

An argument for theism from certain values

Some things, such as human life, love, the arts and humor, are very valuable. An interesting question to ask is why they are so valuable?

A potential answer is that they have their value because we value (desire, prefer, etc.) them. While some things may be valuable because we value them, neither life, love, the arts nor humor seem to be such. People who fail to value these things is insensitive: they are failing to recognize the great value that is there. (In general, I suspect that nothing of high value has the value it does because we value it: our ability to make things valuable by valuing them is limited to things of low and moderate value.)

A different answer is that these things are necessarily valuable. However, while this may be true, it shifts the explanatory burden to asking why they are necessarily valuable. For simplicity, I’ll thus ignore the necessity answer.

It may be that there are things that are fundamentally valuable, whose value is self-explanatory. Perhaps life and love are like that: maybe there is no more a mystery as to why life or love is valuable than as to why 1=1. Maybe.

But the arts at least do not seem to be like this. It is puzzling why arranging a sequence of typically false sentences into a narrative can make for something with great value. It is puzzling why representing aspects of the world—either of the concrete or the abstract world—in paint on canvas can so often be valuable. The value of the arts is not self-explanatory.

Theism can provide an explanation of this puzzling value: Artistic activity reflects God’s creative activity, and God is the ultimate good. Given theism it is not surprising that the arts are of great value. There is something divine about them.

Humor is, I think, even more puzzling. Humor deflates our pretensions. Why is this so valuable? Here, I think, the theist has a nice answer: We are infinitely less than God, so deflating our pretensions puts us human beings in the right place in reality.

There is much more to be said about arts and humor. The above is meant to be very sketchy. My interest here is not to defend the specific arguments from the value of the arts and humor, but to illustrate arguments from value that appear to be a newish kind of theistic argument.

These arguments are like design arguments in that their focus is on explaining good features of the world. But while design arguments, such as the argument from beauty or the fine-tuning argument, seek an explanation of why various very good features occur, these kinds of value arguments seek an explanation of why certain features are in fact as good as they are.

The moral argument for theism is closely akin. While in the above arguments, one seeks to explain why some things have the degree of value they do, the moral argument can be put as asking for an explanation of why some things (more precisely, some actions) have the kind of value they do, namely deontic value.

Closing remarks

1. Just as in the moral case, there is a natural law story that shifts the argument’s focus without destroying the argument for theism. In the moral case, the natural law story explains why some actions are obligatory by saying that they violate the prescriptions for action in our nature. But one can still ask why there are beings with a nature with these prescriptions and not others. Why is it that, as far as we can tell, there are rational beings whose nature prescribes love for neighbor and none whose nature prescribes hatred for neighbor? Similarly, we can say that humor is highly valuable for us because our nature specifies humor as one of the things that significantly fulfills us. (Variant: Humor is highly valuable for us because it is our nature to highly value it.) But we can still ask why there are rational beings whose nature is fulfilled by the arts and humor, and, as far as we can tell, none whose nature is harmed by the arts or humor. And in both the deontic and non-deontic cases, there is a theistic answer. For instance, God creates rational beings with a nature that calls on them to laugh because any beings that he would create will be infinitely less than God and hence their sensor humor will help put them in the right place, thereby counteracting the self-aggrandizement that reflection on one’s own rationality would otherwise lead to.

2. Just as in the moral case there is a compelling argument from knowledge—theism provides a particularly attractive explanation of how we know moral truths—so too in the value cases there is a similar compelling argument.

Life and self-representation

Here’s another try at an account of life. Maybe:

1. x is alive if and only if x has a non-derivative self-representation.

Consider: Anything that engages in reproduction must represent itself in order to reproduce (note: the growth of a crystal is not reproduction, however, because it does not make another crystal in the image of its own self-representation). Indeed, (1) covers all the organisms we are confident are organisms. And whether a virus represents itself non-derivatively or only derivatively in relation to the transcription mechanisms of a host is unclear, and (1) rightly thus rules that it is unclear whether a virus is alive.

Moreover, God and angels know themselves, and do so non-derivatively, so they count as alive according to (1).

It could be that (1) is a necessary truth, but nonetheless does not capture the concept of life. For there seems to be something more to life than just non-derivative self-representation, even if it turns out that necessarily all and only the non-derivative self-representers are alive. Aquinas thinks life needs operation or activity.

Here is a suggestion that expands on (1):

2. x is alive if and only if x pursues an end for itself in the light of a non-derivative self-representation.

Thus something that merely thinks of itself, without having any ends, won’t be alive. On the other hand, anything that intentionally pursues ends that it non-derivatively represents itself as having satisfies (2). So, once again, God and angels count as alive. And so does any organism, since pursuit of reproduction always satisfies (2).

Yet another life-based argument against thinking machines

Here’s yet another variant on a life-based argument against machine consciousness. All of these arguments depend on related intuitions about life. I am not super convinced by them, but they have some evidential force I think.

1. Only harm to a living thing can be a great intrinsic evil.

2. If machines can be conscious, then a harm to a machine can be a great intrinsic evil.

3. Machines cannot be alive.

4. So, harm to a machine cannot be a great intrinsic evil. (1 and 3)

5. So, machines cannot be conscious. (2 and 4)

Life, thought and artificial intelligence

I have an empirical hypothesis that one of the main reasons why a lot of ordinary people think a machine can’t be conscious is that they think life is a necessary condition for consciousness and machines can’t be alive.

The thesis that life is a necessary condition for consciousness generalizes to the thesis that life is a necessary condition for mental activity. And while the latter thesis is logically stronger, it seems to have exactly the same plausibility.

Now, the claim that life is a necessary condition for mental activity (I keep on wanting to say that life is a necessary condition for mental life, but that introduces the confusing false appearance of tautology!) can be understood in two ways:

1. Life is a prerequisite for mental activity.

2. Mental activity is in itself a form of life.

On 1, I think we have an argument that computers can’t have mental activity. For imagine that we’re setting up a computer that has mental activity, but we stop short of making it engage in the computations that would make it engage in mental activity. I think it’s very plausible that the resulting computer doesn’t have any life. The only thing that would make us think that a computer has life is the computational activity that underlies supposed mental activity. But that would be a case of 2, rather than 1: life wouldn’t be a prerequisite for mental activity, but mental activity would constitute life.

All that said, while I find the thesis that life is a necessary condition for mental activity, I am more drawn to 2 than to 1. It seems intuitively correct to say that angels are alive, but it is not clear that we need anything more than mental activity on the part of angels to make them be alive. And from 2, it is much harder to argue that computers can’t think.

Disconnected bodies and lives

We can imagine what it is like for a living to have a spatially disconnected body. First, if we are made of point particles, we all are spatially disconnected. Second, when a gecko is attacked, it can shed a tail. That tail then continues wiggling for a while in order to distract the pursuer. A good case can be made that the gecko’s shed tail remains a part of the gecko’s body while it is wiggling. After all, it continues to be biologically active in support of the gecko’s survival. Third, there is the metaphysical theory on which sperm remains a part of the male even after it is emitted.

But even if all these theories are wrong, we should have very little difficulty in understanding what it would mean for a living thing to have a spatially disconnected body.

What about a living thing having a temporally disconnected life? Again, I think it is not so difficult. It could be the case that when an insect is frozen, it ceases to live (or exist), but then comes back to life when defrosted. And even if that’s not the case, we understand what it would mean for this to be the case.

But so far this regarded external space and external time. What about internally spatially disconnected bodies and internally temporally disconnected lives? The gecko’s tail and sperm examples work just as well for internal as well as external space. So there is no conceptual difficulty about a living thing having a disconnected body in its inner space.

But it is much more difficult to imagine how an organism could have an internal-time disconnect in its life. Suppose the organism ceases to exist and then comes back into existence. It seems that its internal time is uninterrupted by the external-time interval of non-existence. An external-time interval of non-existence seems to be simply a case of forward time-travel, and time-travel does not induce disconnectes in internal time. Granted, the organism may have some different properties when it comes back into existence—for instance, its neural system might be damaged. But that’s just a matter of an instantaneous change in the neural system rather than of a disconnect in internal time. (Note that internal time is different from subjective time. When we go under general anesthesia, internal time keeps on flowing, but subjective time pauses. Plants have internal time but don’t have subjective time.)

This suggests an interesting apparent difference between internal time and internal space: spatial discontinuities are possible but temporal ones are not.

This way of formulating the difference is misleading, however, if some version of four-dimensionalism is correct. The gecko’s tail in my story is four-dimensional. This four-dimensional thing is connected to the four-dimensional thing that is the rest of the gecko’s body. There is no disconnection in the gecko from a four-dimensional perspective. (The point particle case is more complicated. Topologically, the internal space will be disconnected, but I think that’s not the relevant notion of disconnection.)

This suggests an interesting pair of hypotheses:

• If three-dimensionalism is true, there is a disanalogy between internal time and internal space with respect to living things at least, in that internal spatial disconnection of a living thing is possible but internal temporal disconnection of a living thing is not possible.

• If four-dimensionalism is true, then living things are always internally spatiotemporally connected.

But maybe these are just contingent truths Terry Pratchett has a character who is a witch with two spatially disconnected bodies. As far as the book says, she’s always been that way. And that seems possible to me. So maybe the four-dimensional hypothesis is only contingently true.

And maybe God could make a being that lives two lives, each in a different century, with no internal temporal connection between them? If so, then the three-dimensional hypothesis is also only contingently true.

I am not going anywhere with this. Just thinking about the options. And not sure what to think.

Life and non-life

Assume a particle-based fundamental physics. Then the non-living things in the universe outnumber the living by many orders of magnitude. But here is a striking fact given a restricted compositionality like van Inwagen’s, Toner’s or mine on which all there are is in the universe are particles and organisms: the number of kinds of living things outnumbers the number of kinds of non-living things by several orders of magnitude. The number of kinds of particles is of the order of 100, but there are millions of biological species (they may not all correspond to metaphysical species, of course).

Counting by individuals, living things are exceptional. But counting by kinds, physical things are exceptional. Only a tiny portion of the universe is occupied by life. But on the other hand, only a tiny portion of the space of kinds of entities is occupied by non-life.

I am not sure what to make of these observations. Maybe it is gives some credence to an Aristotelian rather than Humean way of seeing the world by putting the the kinds of features as teleology that are found in living things at the center of metaphysics.

More on life

God is alive, angels are alive, people are alive, dogs are alive, worms are alive and trees are alive. What is it that makes them all be alive, while the Milky Way, the Sun, Etna, a car, a Roomba, and an electron are not? I raised a version of this question recently, and since then have had discussions about it with a number of our graduate students, most extensively with Alli Thornton and Hilary Yancey, to whom I am very grateful.

We could say that they are all alive in an analogical sense. But that doesn’t solve the problem, but simply puts a constraint on the shape of a solution. For to solve the problem, we still have to say something about how this particular analogy works.

Here is the best answer I have right now, but it still has some difficulties I will discuss:

• A living thing is one that can act in pursuit of its own ends.

This indeed covers God, angels, people, dogs, worms and trees. Moreover, it produces a gradation of life in respect of the degree and quality with which the thing can act in pursuit of its own ends and the degree of ownership the thing has over its ends. For instance, God is omnipotent and perfectly rational, and he is his own end, so he is most fully alive. All the living creatures, on the other hand, have ultimate ends imposed on them by their nature, to the realization of which end their activity are ordered. However, angels and people additionally make a rational choice of ways to realize their ultimate ends, adopting which ways involves setting themselves intermediate ends. Higher non-human animals like dogs do something that approximates this. Moreover, angels, people and dogs have a wide variety of ways of pursuing that end. On the other hand, trees only pursue a limited variety of ends with a limited variety of means.

A bonus of this definition is that we get the conclusion, which seems intuitively correct, that anything that thinks is alive. For thinking is an end-directed activity—it is directed at action and/or truth. So if we ever make an artificial intelligence system that really thinks, it will be alive.

The Milky Way, the Sun, Mount Etna, a car and a Roomba do not pursue their own ends, I think, if only because they are not substances, and only substances own their ends.

But electrons… This is what troubles me. I think that the fundamental constituents of physical reality, be they particles or fields, are substances. And I think all substances have a teleology, and hence have an end. The distinction I would like to be able to make, however, is between activity in pursuit of an end and teleological activity more generally. Electrons in their characteristic activity are acting teleologically. But their action is not in pursuit of an end. Rather their end is simply to engage in this very activity and nothing more. The activity is teleological, but it does not pursue a telos.

But what if it turns out that electrons do genuinely act in pursuit of an end? Then, perhaps, we will have learned that electrons are a very primitive form of life.

What about God, given divine simplicity, though? God = God’s telos = God’s activity. Well, I think that even if God’s activity is identical with God’s telos, one can make a conceptual distinction that allows one to say that God acts for the sake of that telos, a distinction that perhaps is not there in the case of the electron.

As you can see, I am still not very happy with the account. But it’s the best I have right now.

Life

Accounts of biological life characterize it by lists of features such as “reproduction, metabolism, functional organization, growth, responsiveness to the environment, movement, and short- and long-term adaptations” (SEP s.v. life). But Jewish, Christian and Muslim theists have reason to worry about such accounts of life in the light of the fact that our scriptures present God as the paradigm of a living being.

Here are some options:

Option 1: Modify one’s theology to make God fit with something pretty close to one of the biological accounts of life. Mormonism is a fairly radical example of this. A more moderate version might be some version of process theology, though one may need to jettison some features, like metabolism and growth.

Option 2: Trinitarians have this option available: The Son proceeds from the Father and the Spirit from the Father and/through the Son and these processions could count as reproduction. Moreover, because Trinitarian processions multiply persons but the resulting persons are one God, Trinitarian reproduction has an internality that might count as a kind of growth—not that the divine essence grows, but that the number of persons of the one God grows. This solution would have the important consequence that the Old Testament texts that present God as living are proto-Trinitarian. Obviously, this solution is unlikely to be attractive to Jews and Muslims, though there may be some Kabbalistic analogue that might appeal to some Jews. Moreover, unless one adopts some version of process theology, this solution still requires one to drop a number of the features in traditional accounts of biological life, such as metabolism, movement and adaptation.

Option 3: Replace the biological accounts of life with something radically different which makes God a paradigm instance of life. Here are three such possibilities for characterizing life:

A. Living things are ones that have some mental property like consciousness or purposefulness.

B. Living things have teleology.

C. Living things are ones that have a well-being, that are capable of being well.

Suboption A is pretty radical: it requires either saying that plants have a mental life or that plants aren’t alive. I think it’s not that crazy to say that plants have something like mental life. Maybe they are aware of their environment in a way that goes robustly beyond the mere data processing of a digital thermometer. And it seems plausible that one can ascribe a certain kind of purposefulness to plant processes.

Suboption B is pretty close to the purposefulness variant of suboption A, but teleology is a more general concept than mental purposefulness. For me, the main difficulty with suboption B is that I think all substances have teleology. And I don’t want to extend life to elementary particles. But those who do not think that teleology extends to all substances might like Suboption B.

Suboption C is, of course, related to Suboption B. I have the same worry about C as about B: I think all substances that have teleology have a well-being. Elementary particles have well-being—the only difference between them and organic substances is that as far as we can tell, elementary particles are always well. This is of course very controversial, and those who do not accept it may like C.

There are, no doubt, other options and suboptions. I am attracted to Options 2 and 3A.

Life science and physical science

I've been thinking that in a nutshell one could put much of the distinctiveness of Aristotelian philosophy as follows: life science is at least as fundamental as physical science.

The cause of a living thing is alive

1. Every known cause of a living thing includes a living thing.
2. Therefore, probably, every cause of a living thing includes a living thing. (Induction)
3. Therefore, either there is (a) an infinite regress of living things, (b) circular causation among living things, or (c) an uncaused living thing.
4. But (a) and (b) are false.
5. So there is an uncaused living thing.

(Et hoc dicimus deum.)

Why is marriage sacred?

Many religions that disagree on many other things treat marriage as something sacred, not just a contract. Moreover, many non-religious people—though not all—have intuitions that point in that direction. Let's take all these intuitions at face value. Marriage is sacred.

Why?

Well, a paradigm of the uncontroversially sacred—something that we except to see connected to rituals across religions—is life. We are not surprised to see funerals or baptisms in a religion. Maybe at some deep level it is puzzling why human life is sacred (if materialism is true, this may be especially puzzling), but that human life is treated as sacred is not puzzling.

A student pointed out to me this morning that we can attempt to account for the sacredness of marriage by pointing to the sacredness of the new joint life of the couple. They become one flesh after all. Indeed, it is as if a new human life came into existence. And if the analogy is tight enough, that makes sense of its as being sacred.

But while I think this is all true, I suspect that the reason why marriage has been so widely treated as sacred may be a more literal connection to new life: it is a relationship tied to literal new human life, to procreation. Literal new human life is sacred. The sacred infects what is related to it. The message of a book is sacred, so the volume it's in is treated as a holy book. Marriage, on this picture, is tied to procreation.

But of course we and our ancestors know that not every marriage results in procreation and that procreation can happen outside of marriage. So the tie between marriage and procreation has to be carefully formulated. I don't think we want to say it's just a statistical tie. That would undermine the reason for taking marriage to be sacred. Rather, I suspect it's a normative tie. There is more than one way one could expand on this tie.

One option is to say that marriage is a relationship that normally results in children. One would expect a relationship that normally results in something sacred to have something sacred about it.

However, this option has the consequence that a marriage without children is lacking something normal to it, like a three-legged sheep lacks a leg. But is it right to say that a couple who got married in their 60s has a defective relationship? Well, the phrase "defective relationship" leads astray. It suggests that there is something wrong with what the people are doing. And in that sense, the couple who got married in their 60s don't have a defective relationship just because they don't have children. But if we think of it as a defect in the same way that a sheep having three legs is a defect, then that phrase may not be incorrect. A couple who gets married late in life may well have a quite appropriate sadness that they were unable share a larger portion of their life, and in particular a sadness that they were unable to share their fertility. So I don't think the case of elderly couples is a serious problem for the view that the tie between marriage and procreation is that children normally result from marriage. And the view explains why it can feel so tragic to be infertile.

Another option would be that marriage is a relationship that makes having children morally permissible. It is a relationship that licenses procreation. One shouldn't here have a picture of the state or the church giving one a license to procreate: marriage comes from an exchange of vows between the future spouses, and it is their giving themselves in marriage to one another—something that in principle can happen without a state or a church being involved—is what morally licenses the procreation on this view. It is only with the kind of commitment that is found in marriage that a couple could permissibly tie themselves to each other by having a child together. But it makes some sense that taking up the commitment which makes the production of human life permissible would be infected with the sacredness of human life. Still, in the end this doesn't seem quite to get the full story. For instance, if a married unemployed couple is so poor that they cannot adequately care for their children, then it could be morally impermissible for them to procreate. Getting a job could then render procreation morally permissible. But that doesn't make the job be a sacred thing, at least not in the way marriage is.

In the end, I suspect that all three stories—the story of the new joint life of the couple, of marriage normally resulting in children, and of marriage in principle morally permitting a couple to have children—are a part of the truth. And, as a colleague reminded me, there is the mirroring of the life of the Trinity.