If materialism is true, we can't die in constant pain

Here is an unfortunate fact:

1. The last minute of your life can consist of constant conscious pain.

Of course, I think all pain is conscious, but I might as well spell it out. The modality of the “can” in this post will be something fairly ordinary, like some sort of nomic possibility.

Now say that a reference frame is “ordinary for you” provided that it is a reference frame corresponding to something moving no more than 100 miles per hour relative to your center of mass.

Next, note that switching between reference frames should not turn pain into non-pain: consciousness is not reference-frame relative. Thus:

2. If the last minute of your life consists of constant conscious pain, then in every reference frame that is ordinary for you, in the last half-minute of your life you are in constant conscious pain.

Relativistic time-dilation effects of differences between “ordinary” frames will very slightly affect how long your final pre-death segment of pain is, but will not shorten that segment by even one second, and certainly not by 30 seconds.

Next add:

3. If materialism is true, then you cannot have a conscious state when you are the size of a handful of atoms.

Such a small piece of the human body is not enough for consciousness.

But now (1)–(3) yield an argument against materialism. I have shown here that, given the simplifying assumption of special relativity, in almost every reference frame, and in particular in some ordinary frames, your life will end with you being the size of a handful of atoms. If materialism is true, in those frames towards the very end of your life you will have to exist without consciousness by (3), and in particular you won’t be able to have constant conscious pain (or any other conscious state) for your last half-minute.

Our sharp existence

This argument is fairly well trodden, but I still have to say that I find it quite compelling:

1. If physicalism is true, then there was no sharp time at which I came into existence.

2. There was a sharp time at which I came into existence.

3. So, physicalism is false.

Why think (1) is true? Well, if physicalism is true, there is nothing more to me than an arrangement of particles. And which exact arrangements count as sufficient for my existence seems quite vague. And why think (2) is true? Well, if there is no sharp time at which I came into existence, then there will be worlds where it is vague whether I ever exist at all. For instance, if it is vague whether I already existed by time t₁, then imagine a world just like ours up to t₁, but where immediately thereafter everything is annihilated. If it is vague whether I existed by time t₁ in our world, then it that world it will be vague whether I ever exist. But it can’t be vague whether I ever exist—vague existence is an impossibility.

Objection 1: There are many entities very much like me, each of which comes into existence at a sharp time, sharing most of their particles, and I am one of them. None of these entities is privileged, but as it happens I am only one of them. The entities differ in fine details of persistence and existence conditions.

Response: If none are privileged, then all these entities are persons. And so in my armchair there are many persons, and likewise wherever any human being is, there are many persons. Now, notice that there is more room for such “slight variation” when an individual is physically larger (i.e., has more particles). So it follows from the view that where there is a larger person, there are more persons. All the persons co-located with me have presumably the same experiences and the same rights (since none are privileged). So it follows that if you have a choice between benefiting a larger and a smaller person, you should benefit the larger. This sizeism is clearly absurd.

Objection 2: A Markosian-style view on which there are brute facts about composition can say that there is only entity where I am, and the other clouds of particles do not compose an entity.

Response: Yes, but while that counts as materialism, it doesn’t count as physicalism. It adds to the fundamental ontology something beyond what physical science talks about, namely entities that are brutely composed. Moreover, presumably persons are causes. So the story adds to physicalism additional causes.

Objection 3: Nobody can say that there was a sharp time at which I came into existence.

Response: It’s easy for the dualist to say it. I come into existence when my soul comes into existence, joined to some bit of matter. There is no vagueness as to when this happens, but of course the details are not empirically knowable.

Are we finite?

Here’s a valid argument with plausible premises:

1. A finite being has finite value.

2. Any being with finite value may be permissibly sacrificed for a sufficiently large finite benefit.

3. It is wrong to sacrifice a human for any finite benefit.

4. So, a human has infinite value. (2 and 3)

5. So, a human is an infinite being. (1 and 4)

That conclusion itself is interesting. But also:

6. Any purely material being made of a finite amount of matter is a finite being.

7. If human beings are purely material, they are made of a finite amount of matter.

8. So, human beings are not purely material. (5, 6 and 7)

I am not sure, all that said, whether I buy (2). I think a deontology might provide a way of denying it.

And, of course, work needs to be done to reconcile (5) with the tradition that holds that all creatures are finite, and only God is infinite. Off-hand, I think one would need to distinguish between senses of being “infinite”. Famously, Augustine said that the numbers are finite because they are contained in the mind of God. There is, thus, an absolute sense of the infinite, where only God is infinite, and anything full contained in the divine mind is absolutely finite. But surely there is also a sense in which there are infinitely many numbers! So there must another sense of the infinite, and that might be a sense in which humans might be infinite.

Nor do I really know what it means to say that a human is infinite.

Lots of room for further research if one doesn’t just reject the whole line of thought.

Materialism and incompleteness

It is sometimes thought that Goedel’s incompleteness theorems yield an argument against materialism, on something like the grounds that we can see that the Goedel sentence for any recursively axiomatizable system of arithmetic is true, and hence our minds cannot operate algorithmically.

In this post, I want to note that materialism is quite compatible with being able to correctly decide the truth value of all sentences of arithmetic. For imagine that we live in an infinite universe which contains infinitely many brass plaques with a sentence of arithmetic followed by the word “true” or “false”, such that every sentence of arithmetic is found on exactly one brass plaque. There is nothing contrary to materialsim in this assumption. Now add the further assumption that the word “true” is found on all and only the plaques containing a true sentence of arithmetic. Again, there is nothing contradicting materialism here. It could happen that way simply by chance movements of atoms! Next, imagine a machine where you type in a sentence of arithmetic, and the machine starts traveling outward in the universe in a spiral pattern until it arrives at a plaque with that sentence, reads whether the sentence is true or false, and comes back to you with the result. This could all be implemented in a materialist system, and yet you could then correctly decide the truth value of every sentence of arithmetic.

Note that we should not think of this as an algorithmic process. So the way that this example challenges the argument at the beginning of this post is by showing that materialism does not imply algorithmism.

Objection 1: The plaques are a part of the mechanism for deciding arithmetic, and so the argument only shows that an infinite materialistic machine could decide arithmetic. But our brains are finite.

Response: While our brains are finite, they are analog devices. An analog system contains an infinite amount of information. For instance, suppose that my brain particles have completely precise positions (e.g., on a Bohmian quantum mechanics). Then the diameter of my brain expressed in units of Planck length at some specific time t is some decimal number with infinitely many significant figures. It could turn out that this infinitely long decimal number encodes the truth values of all the sentences of arithmetic, and a machine that measures the diameter of my brain to arbitrary precision could then determine the truth value of every arithmetical statement. Of course, this might turn out not to be compatible with the details of our laws of nature—it may be that arbitrary precision is unachievable—but it is not incompatible with materialism as such.

Objection 2: In these kinds of scenarios, we wouldn’t know that the plaques are right.

Response: After verifying a large number of plaques to be correct, and finding none that we could tell are incorrect, it would be reasonable to conclude by induction that they are all right. However, if the plaques are in fact due to random processes, this inductive conclusion wouldn’t constitute knowledge, except on some versions of reliabilism (which seem implausible to me). But it could be a law of nature that the plaques are right—that’s compatible with materialism. In any case, here the discussion gets complicated.

Human worth and materialism

1. A typical human being has much more intrinsic value than any 80 kg arrangement of atoms.

2. If materialism is true, a typical human being is an 80 kg arrangement of atoms.

3. So, materialism is not true.

Animalist functionalism

The only really plausible hope for a materialist theory of mind is functionalism. But the best theory of our identity, materialist or not, is animalism—we are animals.

Can we fit these two theories together? On its face, I think so. The thing we need to do is to make the functions defining mental life be functions of the animal, not of the brain as such. Here are three approaches:

1. Adopt a van Inwagen style ontology on which organisms exist but brains do not. If brains don’t exist, they don’t have functions.

2. Insist that some of the functions defining mental life are such that they are had by the animal as a whole and not by the brain. Probably the best bet here are the external inputs (senses) and outputs (muscles).

3. Modify functionalism by saying that mental properties are properties of an organism with such-and-such functional roles.

I think option 2 has some special difficulties, in that it is going to be difficult to define “external” in such a way that the brain’s connections to the rest of the body don’t count as external inputs and outputs and yet we allow enough multiple realizability to make very alien intelligent life possible. One way to fix these difficulties with option 2 is to move it closer to option 3 by specifying that the external inputs and outputs must be inputs and outputs of an organism.

Options 1 and 3, as well as option 2 if the above fix is used, have the consequence that strong AI is only possible if it is embedded in a synthetic organism.

All that said, animalist functionalism is in tension with an intuition I have about an odd thought experiment. Imagine that after I got too many x-rays, my kidney mutated to allow me exhibit the kinds of functions that are involved in consciousness through the kidney (if organism-external inputs and outputs are required, we can suppose that the kidney gets some external senses, such as a temperature sense, and some external outputs, maybe by producing radio waves, which help me in some way) in addition to the usual way through the brain, and without any significant interaction with the brain’s computation. So I am now doing sophisticated computation in my kidney of a sort that should yield consciousness. On animalist functionalism, I should now have two streams of consciousness: one because of how I function via the brain and another because of how I function via the mutant kidney. But my intuition is that in fact I would not be conscious via the kidney. If there were two streams of consciousness in this situation (which I am not confident of), only one would be mine. And that doesn’t fit with animalist functionalism (though it fits fine with non-animalist functionalism, as well as with animalist dualism, since the dualist can say that the kidney’s functioning is zombie-like).

Given that functionalism is the only really good hope we have right now for a materialist theory of mind, if my intuition about the mutant kidney is correct, this suggests that animalism provides evidence against materialism.

Antiexplanation

If an explanation is a truth or hypothesis that removes or would remove mystery from the proposition to be explained, then an antiexplanation is a truth or hypothesis that adds or would add mystery to the proposition to be explained. Like in the case of explanations, we need to be sensitive to context with antiexplanations. That Alice dislikes bananas is, in typical contexts, antiexplanatory of why Alice ate the banana. But if we add to the background that it’s Lent and Alice wishes to do penance, then Alice’s dislike of bananas becomes explanatory.

It is widely held, though still moderately controversial, that:

1. The fact that a hypothesis p is explanatory of some known truth is evidence for p.

A parallel claim about antiexplanations would:

2. The fact that a hypothesis p is antiexplanatory of some known truth is evidence against p.

This sounds even more plausible than (1). In a typical context, the antiexplanatoriness of a dislike of bananas to actual consumption of a banana provides evidence that Alice who ate a banana does not dislike bananas. Similarly, the fact that Bob is in perfect health is antiexplanatory of Bob’s death, and hence if Bob has died, we have evidence that Bob’s health was imperfect.

There are lots of explanatory arguments in philosophy based on (1). But it would be worth exploring whether one can’t also give antiexplanatory arguments based on (2).

In fact, I think some fairly intuitive arguments can be rephrased as antiexplanatory arguments. For instance:

3. Materialism is antiexplanatory of consciousness.

4. Consciousness is a known fact.

5. So, we have evidence against materialism.

The thought behind (3) is simply that there is intuitively something particularly mysterious about a purely material thing having a conscious point of view.

C. S. Lewis’s version of the moral argument for theism can be taken to be in part an antiexplanatory argument.

6. Atheism is antiexplanatory of moral law.

7. Moral law is a known fact.

8. So, we have evidence against atheism.

Further evaluation of such arguments would call for a deeper philosophical analysis of antiexplanation and an examination of (2). This is a task worth doing. Someone should do it.

An argument against naturalism from the concept of the numinous

1. If naturalism about our minds is true, then the correct account of intentionality is causal.

2. On a causal account of intentionality, our possession of an irreducible concept is caused by something which falls under that concept.

3. The concept of the numinous is irreducible.

4. Therefore, if naturalism about our minds is true, our possession of the concept of the numinous is caused by something numinous. (1–3)

5. If there is anything numinous, then naturalism in general is false.

6. If naturalism about our minds is not true, then naturalism in general is false.

7. So, naturalism in general is false. (4–6)

What do I mean by “the numinous”? Since I claim it to be irreducible, I had better not try to define it. But I can point to it by means of our experiences of the holy, the uncanny, etc.: see Rudolf Otto’s book on the holy.

I think the best objection to the argument is to say that numinous can be reduced to the negation of the natural. But that objection seems to me to be mistaken. Imagine some simple particle-like thing that doesn’t interact with anything else in a way that is governed by the laws of nature. That thing wouldn’t be numinous. Likewise, not all magic is numinous: quite a bit of the magic in the Harry Potter stories is not numinous at all (there is nothing numinous about the chocolate frogs).

If materialism is true, God exists

Causal finitism is the doctrine that backwards infinite causal histories are impossible.

1. If the xs compose y, then y cannot have caused all of the xs.

2. If materialism is true and causal finitism is false, then it is possible to have a human being that (a) is composed of cells and (b) caused each of its cells via a backwards infinite regress.

3. So, if materialism is true, causal finitism is true. (1, 2)

4. If causal finitism is true, then God exists.

5. So, if materialism is true, God exists. (3, 4)

6. If God exists, the materialism is false.

7. So, materialism is false. (5, 6)

Premise (1) is a strengthening of a plausible principle banning self-causation.

Premise (2) follows from the fact that we are causes of all our present cells. If presentism is true, that completes the argument against materialism as in my previous post. But if eternalism or growing block are true, then we may also be composed of our past cells. And we didn’t cause our first cells. However if causal finitism is false, then it’s very plausible that backwards infinite causal regresses are possible, and so we could have existed from eternity, continually producing new cells, with the old ones dying.

Premise (4) is backed by a version of the kalaam argument.

Premise (6) is definitional if we understand materialism strongly enough to apply not just to us but to all reality. If we understand materialism more weakly, then the argument “only” yields the conclusion (5) that if materialism is true, God exists.

If presentism is true, materialism is false

1. If the xs compose y, then y cannot have caused all of the xs.

2. I caused all my present cells.

3. If presentism is true, then all my cells are present cells.

4. So, if presentism is true, then I caused all my cells. (2, 3)

5. If materialism is true, then I am composed of my cells.

6. If materialism is true, then I did not cause all of my cells. (1, 5)

7. So, if presentism is true, materialism is not true. (4, 6)

Synchronization and the unity of consciousness

The problem of the unity of consciousness for materialists is what makes activity in different areas of the physical mind come together into a single phenomenally unified state rather than multiple disconnected phenomenal states. If my auditory center active in the perception of a middle C and my visual center is active in the perception of red, what makes it be the case that there is a single entity that both hears a middle C and sees red?

We can imagine a solution to this problem in a computer. Let’s say that one part of the computer has and representation of red in one part (of the right sort for consciousness) and a representation of middle C in another part. We could unify the two by means of a periodic synchronizing clock signal sent to all the parts of the computer. And we could then say that what it is for the computer to perceive red and middle C at the same time is for an electrical signal originating in the same tick of the clock to reach a part that is representing red (in the way needed for consciousness) and to reach a part that is representing middle C.

On this view, there is no separate consciousness of red (say), because the conscious state is constituted not just by the representation of red (say) in the computer’s “visual system”, but by everything that is reached by the signals emanating from the clock tick. And that includes the representation of middle C in the “auditory system”.

The unification of consciousness, then, would be the product of the synchronization system, which of course could be more complex than just a clock signal.

This line of thought shows that in principle the problem of the unity of consciousness is soluble for materialists if the problem of consciousness is (which I doubt). This will, of course, only be a Pyrrhic victory if it turns out that no similar pervasive synchronization system is found in the brain. The neuroscience literature talks of synchronization in the brain. Whether that synchronization is sufficient for solving the unity problem may be an empirical question.

The above line of thought also strongly suggests that if materialism is true, then our internal phenomenal timeline is not the same as objective physical time, but rather is constructed out of the synchronization processes. It need not be the case for this that the representation of red and the representation of middle C happen at the same physical time. A part further from the clock will receive the synchronizing signal later than a part closer to the clock, and so the synchronization process may make two events that are not simultaneous in physical time be simultaneous in computer time. I suspect that a similar divide between mental time and physical time is true even if dualism is (as I think) true, but for other reasons.

Microphysics and philosophy of mind

Much (but not all) contemporary philosophy of mind is written as if microphysics were fundamental physics. But as far as I know, only on those interpretations of quantum mechanics that disallow indeterminacy as to the number of particles can microphysics be fundamental physics. The most prominent such interpretation is Bohmianism. On most other interpretations, the most we can say about the number of particles is that we are in a superposition between states with different numbers of particles. But reality has to have determinate numbers of fundamental entities. The picture of reality we get from both relativity theory and mainstream interpretations of quantum mechanics other than Bohmianism and its close cousins is that fundamental physical reality consists of global entities such as the spacetime manifold or the wavefunction of the universe rather than microscopic entities like particles. (I am attracted to a non-mainstream interpretation on which the fundamental physical entities may include mid-sized things like dogs and trees.)

Sometimes, pretending microphysics is fundamental physics is excusable. For certain discussions, it doesn’t matter what the fundamental physics is—the arguments work equally well for global and local fundamental entities. In other cases, all that matters is relative fundamentality. Thus, facts about chemistry might be held to be more fundamental relative to biology, and facts about microphysics might be fundamental relative to chemistry, even if the microphysics facts themselves are not fundamental simpliciter, being reducible, say, to facts about global fields.

But even when the arguments do not formally rely on fundamental physics being microphysics, it is risky in a field so reliant on intuition to let one’s intuitions be guided by acting as if fundamental physics were microphysics. And doing this is likely to mis-focus one’s critical attention, say focusing one more on the puzzle of why the functioning of various neurons produces a unified consciousness than on the puzzle of how the functioning of a handful of global entities results in the existence of billions of minded persons.

A tale of two universes

Suppose that Mary lives in a universe whose physics is radically different from ours. She loves mathematics and is amazingly good at it. She has very little knowledge of biology, beyond what little superficial information she can glean by turning her eye-stalks on herself while spending all her life suspended in a vortex of Z-force. One day, she is given a complete description of the physical state of the laws of our universe and of the physical arrangement of matter in the Solar System over the past billion ears. She thinks this is really cool mathematically, and thinks through all the mathematico-physical facts involved.

Here is the question: Does Mary have enough information to know that the Solar System contains conscious life?

If not, physicalism seems to be in trouble.

Another variant of the knowledge argument

We don’t have anybody like Mary who knows all of physics and yet has not yet seen color, and as Dennett has pointed out, it is hard to imagine what things look like from the point of view of someone who knows so much more than we do.

But here is a variant that may be easier for us to wrap our minds about: Imagine two people, one a completely colorblind early 21st century neuroscientist specializing in the visual system and the other a completely colorblind ordinary person. Suppose both receive color vision. If physicalism is true, the neuroscientist knows a lot more about what seeing red is like, even though (because we’re still in the early days of neuroscience) they don’t know that much about it overall. Thus, if physicalism is true, the neuroscientist would learn less by seeing red the first time, and should be less surprised. But would we really expect them to learn less and be less surprised than the ordinary person?

This variant is inspired by a remark I heard Brandon Rickabaugh give in a conference talk, that consciousness only seems more mysterious when one knows more neuroscience.

Against anti-interactionist intuitions

1. Fundamental and non-fundamental things are at least as deeply metaphysically different from each other as physical and non-physical things.

2. Fundamental things can cause non-fundamental things and non-fundamental things can cause fundamental things. (E.g., particles can cause a heap, and lab equipment can cause a particle emission.)

3. Therefore, being at least as deeply metaphysically different as physical and non-physical things are cannot be sufficient for making causal relationships impossible.

Normative powers

Consider:

1. Purely physical things have only physical powers.

2. Normative powers (i.e., powers of producing normative effects, such as promises and commands) are not physical powers.

3. We have normative powers.

4. So, we are not purely physical.

I guess what I am not sure about in this argument is whether “power” is used univocally between “physical powers” and “normative powers”.

Shape and parts

Alice is a two-dimensional object. Suppose Alice’s simple parts fill a round region of space. Then Alice is round, right?

Perhaps not! Imagine that Alice started out as an extended simple in the shape of a solid square and inside the space occupied by her there was an extended simple, Barbara, in the shape of a circle. (This requires there to be two things in the same place: that’s not a serious difficulty.) But now suppose that Alice metaphysically ingested Barbara, i.e., a parthood relation came into existence between Barbara and Alice, but without any other changes in Alice or Barbara.

Now Alice has one simple part, Barbara (or a descendant of Barbara, if objects “lose their identity” upon becoming parts—but for simplicity, I will just call that part Barbara), who is circular. So, Alice’s simple parts fill a circular region of space. But Alice is square: the total region occupied by her is a square. So, it is possible to have one’s simple parts fill a circular region of space without being circular.

It is tempting to say that Alice has two simple parts: a smaller circular one and a larger square one that encompasses the circular one. But that is mistaken. For where would the “larger square part” come from? Alice had no proper parts, being an extended simple, before ingesting Barbara, and the only part she acquired was Barbara.

Maybe the way to describe the story is this: Alice is square directly, in her own right. But she is circular in respect of her proper parts. Maybe Alice is the closest we can have to a square circle?
Here is another apparent possibility. Imagine that Alice started as an immaterial object with no shape. But she acquired a circular part, and came to be circular in respect of her proper parts. So, now, Alice is circular in respect of her proper parts, but has no shape directly, in her own right.

Once these distinctions have been made, we can ask this interesting question:

• Do we human beings have shape directly or merely in respect of our proper parts?

If the answer is “merely in respect of our proper parts”, that would suggest a view on which we are both immaterial and material, a kind of Hegelian synthesis of materialism and simple dualism.

Perdurance, physicalism and mind

According to standard perdurantism, we are four-dimensional beings made out of three-dimensional slices, and properties such as mental ones are primarily had by the slices, and only derivatively by the four-dimensional whole.

Here are two problems with this when conjoined with widely held views.

First, mental states are intrinsic to the entity that has them primarily. But most perdurantists are physicalists. If mental states are intrinsic and had by three-dimensional slices, then it is possible to have a world with just one such three-dimensional slice with mental properties, isolated from other slices. But a single three-dimensional slice, isolated from other slices, does not have the functonal properties that the more plausible physicalist theories of mind require.

Second, it is clearly worse if someone has a constant headache for two hours than for one hour. But if time is continuous, as is widely held, then both the one-hour headache scenario and the two-hour headache scenario have the same infinite number of aching slices that are the primary bearers of the pain. But two scenarios which have the same number of primary painbearers are equally bad. Hence, a two-hour headache is no worse than a one-hour one. Which is absurd.

The perdurantist can escape this by saying that mental states are primarily had by the four-dimensional entity, and the three-dimensional slices, if they have mental states at all, have them derivatively. There are two ways of running this story. One way is that the slices have mental* states: states that aren’t mental states but that ground mental states in the four-dimensional whole. Thus, a four-dimensional entity hurts at time t just in case its slice at t hurts, but hurting isn’t a mental state, and doesn’t have the negative significance of hurting.

A second way is to say that the mental states of the four-dimensional entity reduce to ordinary physical states (positions, shapes, momenta, charges, etc.) of multiple three-dimensional slices.

Another way out of the closure argument

Consider this standard closure of the physical argument for physicalism (Papineau gives one very close to this):

1. Our conscious states have physical effects.

2. All physical effects are fully caused by physical causes.

3. There is (typically) no overdetermination.

4. So, our conscious states are (at least typically) physical.

Many dualists question (2), and epiphenomenalists question (1). But there is another move that seems to me to be promising.

When we say that our conscious states have physical effects, we don’t mean that our conscious states are the full causes of physical effects. Descartes himself would say that the movements of the particles in the pineal gland are partly caused by the conscious choice and partly caused by the prior state of the particles.

In other words, (1) just tells us that our conscious states are partial causes of physical effects. Given this, what (1)–(3) license us in concluding is only:

5. Our conscious states are (at least typically) parts of physical causes.

But to conclude from (5) that our conscious states are physical, it seems we need some premise like:

6. All the parts of physical things are physical.

But (6) is worth questioning. Note first that it is easier to find false than true cases of principles like:

7. All the parts of Fs are Fs

(E.g., electrons are parts of red things, but electrons aren’t red.) So why think (6) is true?

So, it seems that (6) needs some argument.

And in fact there are serious metaphysical views on which (6) is false. Consider, for instance, bundle theory: substances are bundles of properties. Well, rocks are physical objects, but a part of the bundle that makes up a rock will be the abstract entity of rockiness. But abstract entities aren’t physical.

Or take a reading (perhaps a misreading) of Leibniz on which physical objects are constituted by non-physical monads, and suppose that constituents count as parts.

Or, most promisingly, take Aristotle’s view on which all physical objects have form. Form is immaterial, and plausibly non-physical. Hylomorphism thus escapes the closure argument.

More generally, for all we know, the fundamental structure of reality is such that physically fundamental things are not ontologically fundamental but themselves have parts that are not physical.

Pain and a hybrid privation theory of evil

According to Augustine’s privation theory of evil, evil has no positive reality, but is always a lack of something. It seems that theists are committed to the privation theory of evil. For if evil has a positive reality, then obviously that positive reality is other than God. But according to theism, every positive reality other than God is created by God. But God does not create evil. So theism is incompatible with the idea that evil is a positive reality.

However, that argument doesn’t seem to be quite right, as it assumes that the only two options for evil are that

1. Evil is a positive reality,

and

2. evil is a lack.

But in fact it is more plausible to think that

3. an evil is grounded in both a lack and a positive reality.

Consider Alice’s cowardice when she discovers that her employer is producing defective medication and nonetheless does not report this to the FDA. Alice’s cowardice is only partly grounded in by a lack of courage. It is also partly grounded in Alice’s humanity. After all, Alice’s pencil also lacks courage, but does not therefore count as a coward.

This observation is closely related to the fact that a careful definition of the privation theory of evil will specify that evil isn’t just a lack, but a lack of a due good, of a good that ought to be present. And courage should be present in a human but not in a pencil, so that evil is not constituted merely by a lack but by a lack plus whatever—say, humanity—that grounds the dueness of what is lacking. So perhaps the hybrid theory (3) just is a charitable way of understanding the classic Augustianian theory.

Note, too, that (3) can be reconciled with theism just as (2) can. For we need not say that God creates such things as holes that are constituted by combinations of positive and negative realities. We can say that God makes the positive realities, and the holes, shadows and evils are just a logical consequence of what he has made and what he has not made.

Now, one of the main objections to the privation theory of evil is pain, which sure doesn’t seem to be a lack, or even a lack of something due, but rather seems to be a positive reality. But the hybrid privation theory (3) can be reconciled with the phenomenon of pain.

Here’s how. We don’t know what constitutes pain. Start by imagining that a computer could feel pain (something that seems plausible given materialism). We don’t know what kind of program and data would constitute pain, but it might well be encoded as a sequence of zeroes and ones, or lacks and presences of electrical potential. Well, then, that fits perfectly with (3): the pain is constituted by a combination of negative reality—the zeroes—and positive reality—the ones. If we were to fill in all the negative realities, the pain would disappear, as we would have just a sequence of ones, which, we may suppose, wouldn’t be sufficient to constitute pain.

Similarly, if materialism is true, we don’t know what brain states constitute a pain. It is plausible that the brain states that constitute pains are grounded in both positive and negative neural realities. After all, that’s generally how the material representational states we know of work. As I type this sentence, its inscription on the screen is constituted by a combination of absences and presences of light— the black and white pixels. (Things are more complicated with colored text, but the absence of light of particular wavelength is always going to be crucial.) When I say something, the periodic combination of pressure and lack of pressure (i.e., lower pressure) encodes the sound. So, given materialism, it is plausible that pain is grounded in a hybrid of positive and negative states (and that so is pleasure, for that matter).

Now, if materialism is false, there are multiple options. One option is that pains are simple existences, qualia. If so, that’s incompatible with the hybrid privation theory. But we do not know that that theory of pain is true, even if we know dualism to be true. Just as on materialism, pain is constituted by more fundamental states, so too on dualism, pain could be constituted by more fundamental (but immaterial) states. For all we know it is so, and for all we know the more fundamental states are partly negative in nature.

So, whether materialism or dualism is true, for all we know, pain is consistent with the hybrid privation theory. (I should add that I am not actually confident that pain is an evil in itself.)