Tuesday, December 4, 2007

Do non-human animals feel pain?

Assume some form of dualism--whether hylomorphic, substance or property. What is our reason for thinking that non-human animals feel pain? It is presumably that there are situations similar to those that humans find themselves in where animals both exhibit neurological responses similar to human neurological responses correlated with pain and behavioral responses similar to human behavioral responses correlated with pain. Humans in these situations feel pain, and, hence, so do non-human animals that have the same responses.

The argument has the following form: In animals of kind A, states of type C (having such-and-such neurological and behavioral states in the presence of bodily damage) are correlated with states of type D. Therefore, in every kind of animal that can find itself in a state of type C, states of type C are correlated with states of type D. This is in general a pretty weak argument. Consider: "In bats, movements of forelimb muscles are correlated with flying. Therefore, in every kind of animal that can exhibit movements of forelimb muscles, the movements when unimpeded are correlated with flying. (In particular, pigs fly.)" I do not mean that the argument is useless.   Suppose that we were alien visitors and having just landed the only animals we were able to observe were bats. We observed that movements of forelimb muscles are correlated with flying. We might well form the working hypothesis that in all other animals, forelimb muscle movements are correlated with flying. But this hypothesis would carry only a little epistemic weight.

Suppose we are still the aliens who have only observed bats. We now notice burrows on the ground. Sonar reveals that the burrows are being made by small animals--moles--that dig lots of tunnels in the ground, and further sonar observation shows that there is sufficient food for them underground. We conclude as a working hypothesis that these animals spend much of their lives underground. Sonar observations suggest that the animals indeed do have forelimbs. But--and I realize this is a bit unlikely--we cannot tell from the sonar whether or not there are wings (they might be folded back over the body). By the earlier working hypothesis we could conclude that if the moles' forelimbs were to move unimpeded (i.e., in an open space), the moles would fly. But this would be unjustified. For given what we have seen of the moles' lifestyle, we see that flying would be of little if any use to them.

Thus, a defeater to generalizing claims of the form "Animals when in state C exhibit D" from one natural kind to another is found when exhibiting D in state C has significant usefulness in the case of the former kind but has little or no usefulness in the case of the latter kind. And if dualism is true, this seems to be how it is in the case of pain. Conscious pain seems to be of no use to non-human animals. One might say that pain is useful for getting an animal to avoid certain situations. But that may well be incorrect in the case of non-human animals: neural states may well be sufficient to cause the behavior of these animals. It seems plausible that if we could do all the impossibly difficult physics calculations, we could predict what the animals will do based their physical states and the states of the environment. But if dualism is true, the pain is something over and beyond the physical states.

Humans have free will and make decisions through a process that goes beyond the physical functioning of the body. Or so at least hylomorphic and substance dualists are going to say. It is plausible that pain--which according to the dualist goes beyond the physical--is needed in order to inform this non-physical process. But this kind of a use won't be there in the case of non-human animals. Moreover, knowledge has non-instrumental value in the case of humans, and the kind of knowledge that pain conveys thus may have non-instrumental value in the case of humans. It does not seem that plausible that this kind of knowledge has much non-instrumental value for non-human animals.

I am not saying animals don't feel pain. I am simply saying that dualists have good reason to find the argument for animals having pain to be evidentially weak.

An objection to the above is that God exists, and we would be deceived in seeing animals apparently feel pain, and God would not allow for such deception. This objection has some force, but we had better not take the claim that God would not allow deception to imply that in all cases of something seeming a certain way, it is in fact that way. We already know that some animal behaviors seem humanlike but in fact have a different significance in non-humans, so we know to be cautious in inferences from humans to other animals. (Interestingly, the deception argument does not apply in the case of animals who lived before human beings came on the scene. Thus, someone impressed by this argument could hold that before the Fall, there was no animal pain.)

As an application, what I have said implies that the argument for the non-existence of God from the evil in animals' suffering pain is quite weak for dualists. It is weak first of all because the argument for animals' suffering pain will be rightly judged weak by dualists. But it is even weaker than that. For the main reason that could remain, after the above arguments, for a dualist to keep on presuming that animals feel pain is that perhaps something of the non-instrumental value that pain has in human life could be there in animals--maybe truth about the state of one's body is innately valuable. But if that is the argument, then the pain is not an evil, at least not in itself.


Heath White said...

Here is an argument to the contrary.

1. It is wrong to treat animals cruelly, to torture them, etc. (Among other sources for this claim is a very long Judeo-Christian religious tradition.)
2. The (main) reason it is wrong is that it inflicts unwarranted pain on animals.
3. Therefore, animals feel pain.

Alexander R Pruss said...

I am not sure we know (2) to be true. There are other reasons available.

a. Paradigmatic cases of mistreatment of animals are not only painful, but damage the organism. To damage a complex organism is prima facie wrong.
b. It is wrong to do what might well inflict significant pain on an animal without sufficient reason.
c. It is prima facie wrong to do what looks like the causing of pain because it is bad for us. If we made a doll that engaged in extremely realistic pain behaviors, "cruel" treatment and "torture" of the doll would be wrong for virtue ethics reasons.

Moreover, opposed to your argument is the following.
4. We have a prima facie duty to prevent animals from feeling pain.
5. If animals feel pain at all, then mammals do so when they are being preyed on.
6. Therefore, if animals feel pain at all, we have a prima facie duty to prevent mammals from being preyed on.

But I am skeptical of the consequent of (6).

todd buras said...

Dear Alex, I think the most interesting point here is that neural states are sufficient to account for the behavior of animals. This is also true of us. But because we actually experience human pain, first hand, we can establish the correlation of bodily states with pain. Just looking at the behavior and the firing of neurons, etc., gives us no reason to think anything mental is going on "inside" some excitable chunk of meat.

But can't we know something mental is going on (in any other case than our own) by means of testimony, as well as analogy? I wonder if we could skirt the analogical argument by thinking of the chirping, barking, moaning, etc., of non-human animals in pain as a sort of testimonial evidence. They are saying: "That hurts!" Perhaps they are even entreating the stimulus of their pain: "Please stop!" I certainly treat their sounds in this way when I am the cause of their pain. Analogical thinking doesn't really come in. I simply hear what they are saying to me, and trust them for the same reasons I trust other human beings, and would trust aliens who were capable of linguistic communication.

Perhaps I "hear what they are saying" only because of an underlying analogy between their behavior and that of humans. So maybe the appeal to tesitmonial evidence is not independent of the analogy after all. What do you think?

todd buras said...

Dear Alex, here is an additional thought that Mike Murray once used in conversation in order to test my intuitions. It doesn't really engage your post, but it does get to the heart of the matter.

Suppose you are submitting your dog to a surgical procedure. As far as the procedure goes, the only medically important thing is for the dog to be immobile. The vet says there are two ways to make the dog immobile. The expensive way is to give the dog an anesthetic. The cheap way is to strap the dog down very thoroughly and give it no anesthetic. Medically speaking the two procedures are equivalent. The only difference is whether the dog will be conscious. Would you spend the money? What would you think of someone who didn't? The intuitive answers seem clear enough, don't they?

Alexander R Pruss said...


Thanks for some very helpful comments.

1. I don't actually believe that neural states are sufficient to account for human behavior. I think the will--a faculty of the soul--makes a causal contribution. In any case, pain is sometimes non-instrumentally good for us if we take a view of pain as a perceptual state that, in veridical cases, communicates the truth.

2. Here's a way of thinking about my argument. Suppose after a lot of investigation we find in every human brain a tiny black cube (maybe it's the size of a virus, so we missed it previously). We don't have any good story as to how the cube got there or how it causally interacts with the rest of the brain. Further investigation reveals that inside the cube there is a tiny light that glows when and only when the neurological correlate of pain is occurring in the brain and pain behavior is exhibited in the body. How much reason would we have to suppose such cubes are also present in other animals and that there, too, the light glows when the neurological correlate of pain occurs in the brain and pain behavior occurs in the body? I think we would have some reason to think this. It might make a fine working hypothesis. But the evidence would be weak. And if we were able to show a disanalogy between the human and non-human animal (NHA) case, e.g., by showing that there is some useful function played by the light in the human brain but such a light would play no such role in the brains of NHAs, then our confidence that their brains contain such cubes would decrease. If, further, it were shown that the cubes did not originate from humans' organic development--they were not coded for in the DNA--then the confidence that we'd find such a cube in the brain of a NHA would be even lower, I think. Consciousness is, arguably, such a cube.

3. The testimony suggestion is really intriguing. I don't think all pain behavior is like that. It seems to me to be essential to the nature of testimony that it be a communicative act directed at the epistemic agent. If I were to overhear your conversation with Jon, what you said to Jon would not be testimony for me, though it would be evidence. (You could, for instance, with no dishonesty have agreed with Jon that some word in your conversation has a non-standard meaning. I would misunderstand that, and you would have no responsibility for avoiding such misunderstanding.) Likewise, talking in one's sleep is not testimony, though it is evidence.

So the typical case of an animal engaging in pain behaviors is not at all testimony. It is not communicative in intent. On the other hand, a dog coming up to its owner and whimpering while licking the owner's hand is much more like testimony. But the content of the testimony may be ambiguous between being in pain and being in need. But I don't have enough experience with NHAs to tell whether there is such an ambiguity.

4. It seems likely to me that the correlates of pain are in many ways not conducive to the proper functioning of the organism (though in one way they are: they involve the organism moving away from the source of the pain). They put a strain on the organism, say. This is sufficient reason to anesthetize. Moreover, the fact that there is some probability (say 1/2) that animals feel pain is sufficient to make the use of anesthesia in surgery a prima facie duty.

Vlastimil Vohánka said...

Dear Alex,

Thank you very much for this intriguing post, also the comments are fascinating.

1. My only problem is that I can't help and just believe that non-human animals do feel pain, or at least presently do feel pain; the proposition has too high prior probability (or, say, plausibility) for me, though I am not able to argue it out clearly.

I'm like the man in Chesterton's Orthodoxy who was asked for the justification of civilization: "It is very hard for a man to defend anything of which he is entirely convinced. It is comparatively easy when he is only partially convinced. He is partially convinced because he has found this or that proof of the thing, and he can expound it. But a man is not really convinced of a philosophic theory when he finds that something proves it. He is only really convinced when he finds that everything proves it. And the more converging reasons he finds pointing to this conviction, the more bewildered he is if asked suddenly to sum them up. Thus, if one asked an ordinary intelligent man, on the spur of the moment, "Why do you prefer civilization to savagery?" he would look wildly round at object after object, and would only be able to answer vaguely, "Why, there is that bookcase . . . and the coals in the coal-scuttle . . . and pianos . . . and policemen." The whole case for civilization is that the case for it is complex."

2. But I like the hypothesis that before the Fall of humans, there was no animal pain (though there was animal death and mutual killing, as the fossil record suggests).

3. Granted, pain has a good aspect: it typically communicates the truth (about the damage).

Still, 3.1, given there was significant animal pain long before humans, is this positive aspect a morally sufficient reason for God's permitting this pain? I doubt that. Would not be the negative aspect of this animal pain an undefeated moral defeater of the goals the condition of which the pain woud be?

3.2. What could be God's morally sufficient reason for permitting savage natural processes before humans? Significant free will of creatures, soul building, simplicity and elegance of laws, virtues that are logically dependent on evils, overall aesthetic considerations, non-coerciveness of the truth of God's existence or the truth of Christianity (esteemed by Pascal)? But nothing mentioned seems to be a viable candidate.

3.3. It seems there is a possible world W which is exactly like the actual world except that all (and not just some) pre-human animals or animal-like creatures are vegetarians (and except that there is no theological problem of significant animal pain before humans, whereas the non-coerciveness of God's existence or Christianity is sufficiently supplied by other problems). So, what would be the point of the pervasive pre-human animal pain?


Alexander R Pruss said...


All very good questions. I, too, find it close to impossible not to believe that animals feel pain. But, you know, if I had a robot that exhibited very realistic pain behavior when it suffered a malfunction, I would probably find it hard not to think of it as in pain. The phenomenon where patients under general anesthesia exhibit pain behavior is also relevant.

Anyway, here are some options towards answering you.

1. The argument that it is unlikely that God would create a world that contains animal pain is only a good argument against theism if it is not unlikely that there would be animal pain on the alternate hypotheses. The main alternate hypothesis is, presumably, atheism plus unguided evolution. But it is unlikely that there be pain on that hypothesis. (This is an argument Todd Buras told me, which he got from C. Stephen Layman's Letters to Doubting Thomas.) Why? Well, I think the evidence for dualism is very strong. And the likelihood that non-physical states that confer no selective advantage on the organisms associated with them should evolve, and remain in the species, is very low indeed. So animal pain is a problem for both main alternate hypotheses.

2. If dualism is true, and if we know that animals feel pain, then we can use this to mount a transcendental argument for the existence of God. My arguments that we don't have knowledge that animals feel pain have exactly one weakness: my discussion of the question whether God would allow us to be deceived about animals in this respect. I could see how one might go both ways on this. Apart from a theistic view on which God wouldn't allow there to be very widespread quasi-testimony (cf. Todd Buras' comments) for something false, there is no way we can know NHAs feel pain. Hence, if we know that non-human animals feel pain, theism is true. (Moreover, God has to be good. For if he's not, then he might be deceiving us.) Note that this argument does not apply before humans came on the scene.

3. Suppose that before the Fall there was no animal pain. Is predation, red in tooth and claw, in itself a problem? I am not sure. An herbivore kills lots of organisms to survive (think how many wheat organisms are killed for a slice of bread). Granted, the organisms that are killed by carnivores are more complex--they are animals--and hence their death is presumably worse. But, remember, we're working on the hypothesis that the more complex organisms do not feel pain. Moreover, if we're going to have the great diachronic variety of life that we've had, and have it all on one planet, then death may have to be a part of the picture. So the organisms being preyed on would, arguably, die anyway.

Is there anything wrong with an interdependence on which some organisms are there for the nutrition of others? Consider the following possible world: Rabbits run to foxes in order to offer themselves up to the foxes to eat. Would the rabbit-fox relationship be an evil one then? I doubt it--it would be a part of interdependence and biological self-giving. Suppose now that rabbits are there for the benefit of foxes, but the rabbits try to run away from the foxes, as it is in this world. Does the mere fact that rabbits try to run away from the foxes make this particular dependence situation worse than it would otherwise be? Not much, and maybe not at all.

4. If the nature of pain is the perception of damage, then pain, when it is veridical, is intrinsically good. Not just good in some respect, but good simpliciter. For it is good to perceive the truth as it is. Now one might wonder why this particular perception is so, well, distressing. Maybe the nature of damage and perception is such that a vivid perception of damage logically must be distressing. On this view, the evil of distress is a necessary concommitant of the good of perception and this goes some way towards a theodicy.

Suppose, on the other hand, that distress is only contingently tied to the vivid perception of damage. The existence of masochists suggests this, though inconclusively (maybe the masochist doesn't actually feel pain). This could happen in one of two ways. Either the distress is an essential part of pain (so that pain is more than just the vivid perception of damage: it is perception plus distress) or the distress is something over and beyond the pain. In the latter case, it is possible that NHAs feel pain without being distressed in any sense in which distress is an evil. Or at least it might have been so before the fall. In the case where distress is an essential part of pain, it still could be that before the Fall (or even now!) animals instead of having pain had quasi-pain, which is the vivid perception of damage without the distress.

5. It may be that a justification can be given in terms of the value of natural creation participating in the formation of the species through evolution. Evolution is likely to lead, perhaps, to pain and the like. (If evolution doesn't lead to pain, then pain is just as much a problem for the atheist--see point (1).) It may be that something similar to what we see about the value of free will can be said about the value of evolution. It's not soul-building, but it's nature-building. (This is compatible with God from time to time intervening, say to create the human soul.)

6. And then one can always bring in free will. It could well be that the suffering of animals before the Fall was due to the free will of demons or the free will of Adam (acting backwards in time--there is nothing absurd about backwards causation).

Alexander R Pruss said...

Another relevant thought. Most of us believe that the reason not to inflict pain on NHAs is only prima facie. It is perfectly OK to kill innocent NHAs if this is necessary to survival (almost nobody thinks it's wrong to kill a lion that is attacking one; but the lion is innocent; likewise, it is surely right to kill a rabbit if the alternative is one's child starving). This means that the kind of value that animals have is a value that can be traded off against other values, such as scientific knowledge or saving human lives. Humans are ends, but NHAs exist for others (for humans and for other animals). This lowers the bar for theodicy quite a lot.

Diachronic diversity might well be a good theodicy for animal death. There is a Jewish story about God every day creating a new choir of angels which sings its song, and then fades into non-existence. Diachronic diversity is good. Especially given eternalism. :-)

Vlastimil Vohánka said...


Your thoughts are really helpful. Thanks!

Let me, please, final, but more general questions.

When thinking about evil, I repeatedly ask:

1. Should it be rationally expected, "prior" to the creation, that our world (or a world similar to our world) will be created? What would you answer?

2. All (or almost all) conceivable sentences are possibly true, at least prima facie. Now, it is conceivable that there is only God and infinite number of good free rational creatures who perform an infinite number of good acts. So, why God did not create such a possible world?

(This is, again, an instructive objection by Q. Smith, http://qsmithwmu.com/
a_sound_logical_argument_from_evil.htm )

3. Plantinga could respond that every creature with significant libertarian free will sins in every possible world in which it exists, or that every possible world with creatures with significantly free libertarian will contains significant evil. However, pace Plantinga, the opposite seems to be the case: a scenario with such creatures, but without sin or significant evil is conceivable, and so possible.

4. Further, it seems that God is necessarily morally good; it is not possible that he sins, thus he does not have libertarian free will with respect to non/sinning. Still, we do not take it as his imperfection or limitation, and we also claim that God is perfectly free, though in another way than humans. So, why God did not create a world containing only God and an infinite number of necessarily good free rational creatures who perform an infinite number of good acts?

5. W.r.t. (2)-(4), it could be replied:

Humans need to endure and strive against evils in order to achieve their highest good.

John Hick, "An Irenaean Theodicy,": "If, then, God's purpose was to create finite persons embodying the most valuable kind of moral goodness, he would have to create them, not as already perfect beings but rather as imperfect creatures who can then attain to the more valuable kind of goodness through their own free choices as in the course of their personal and social history new responses prompt new insights, opening up new moral possibilities, and providing a milieu in which the most valuable kind of moral nature can be developed. "

Also Christ said, "Greater love has no one than this, that one lay down his life for his friends" (John 15:13). Swinburne wrote that without the evil of death, it would be impossible to accomplish this greatest act of love (Providence and the Problem of Evil).

Here's another similar line of thought by you (from our correspondence): Given the existence of humans, it is likely that God wouldn't want them to overestimate how much he loves them. Hence, for any property P that a human ascribes to God's love for us, God's love for us either has P, or has some better property P*. Thus, God either did become incarnate and die for our sins, or did something even better.

6. In response to (5), one could reply: look at God who is infinitely perfect, non-limited and perfectly free, though he is neither material nor has libertarian free will w.r.t. non/sinning. In other words, God has all the perfections of all material beings, though he is not material, and he has all the perfections of libertarian free will w.r.t. non/sinning, though he does not have such libertarian free will. E.g. Descartes would say that God has these perfections "eminently", though not "formally". Why, the reply continues, could not we similarly say that there is a possible world that contains only God and infinite number of good free rational creatures who perform an infinite number of good acts, whereas this world has all the perfections of our world (including the its perfections of suffering because of love, moral heroism, self-sacrifice, etc)? Is not such a scenario conceivable?

Thank you!

Alexander R Pruss said...


Ad 1: Probably not. There probably are infinitely many axiologically incommensurable worlds.

Ad 2: I take it that the claim is that these rational beings don't do any evil acts. For if we allow that they do evil acts, then for aught that we know that world is our world. I also assume that "free" means "significantly free". Given these assumptions, isn't this idea refuted by the various free will defenses? God cannot do what is logically impossible. In particular, he cannot determine someone to freely act a certain way.

Ad 3: Such a scenario is possible, but may not be feasible--the conditionals of free will might not allow it.

Ad 4 & 6: I think at the heart of libertarianism is not the conviction that we can choose otherwise, but that we are not determined to choose by causes outside of us. Now, if we had to choose rightly, then whatever causes we have (genes, environment, God, etc.) would have determined us to choose rightly, which would be contrary to our significant freedom. However, God has no cause, and so although he has to act rightly, he is not deterministically caused to act rightly by any cause outside of himself.

Vlastimil Vohánka said...

Thanks, Alex.

Ad 2 and 3. As you wrote, there is a distinction between possible and feasible worlds. God cannot create a sinless and flawles world with free creatures. For if one causes a person to make a specific choice, then the choice is no longer free in the libertarian sense. All God can do is create the circumstances in which a person is able to make a free choice and then, so to speak stand back and let the person make that choice. Now this implies, at least according to Plantinga, that there are worlds which are possible in and of themselves, but which God is incapable of creating.

My objection is the following: OK, I admit that God can't cause every creature to make a good choice. But he knows what any creature would choose in any situation (though, again, he can't cause her to choose freely this or that). So, why God does not create only such situations and such free creatures that all free always, freely and by themselves (not by divine causation) make a good choice?

Maybe my objection is naive and I miss something fundamental about the free will theodicy (like that by Plantinga), however, I haven't found the answer yet, though I've read several relevant texts on the issue.

Vlastimil Vohánka said...

I'm sorry, there's an error in my main question.

... why God does not create only such situations and such free creatures that all free creatures always, freely and by themselves (not by divine causation) make a GOOD choice?

Alexander R Pruss said...


Plantinga argues that it is logically possible that there is no situation in which God could create beings that are significantly free who never sin, because it is logically possible that every possible created person has transworld depravity.

Personally, I think that even if this scenario is possible, it is very unlikely.

Here, I think we can do better without Molinism. For without Molinism, God does not know what people would do in hypothetical circumstances, or if he does know it, he cannot make use of this knowledge on pain of an explanatory loop (cf. Adams' explanatory loop argument against Molinism).

Vlastimil Vohánka said...


The issue of Molinism aside, you wrote that according to Plantinga, "it is logically possible that every possible created person has transworld depravity."

Why not to say the opposite: it is logically possible that some possible created person does not have transworld depravity?

Secondly, why do you think the scenario containing only such significantly free creatures that they never sin is unlikely?

Thirdly, is the sense in which the scenario is unlikely relevant for omnipotent God?

Alexander R Pruss said...


Yes, both scenarios are possible according to Plantinga. But God doesn't determine which one obtains. So it is logically possible that the bad one obtains, and it would be logically impossible for God to do anything about it.

I meant that Plantinga's transworld depravity scenario is unlikely.

Vlastimil Vohánka said...



it IS possible that there is a possible world containing only such significantly free creatures that all their choices are good and made genuinely freely (by themselves, not by divine causation)


we do NOT deny Molinism,


what prevents us from asking: why God did not create only such volitional situations and such free creatures that all free creatures would always, freely and by themselves (not by divine causation) make a good choice?

Why God did not create such circumstances and such creatures? I repeat, even in this scenario he would stand back and let the creatures make their choices, without causing them to make that choice.

Alexander R Pruss said...


I don't understand the question.

Plantinga says that either transworld depravity holds or it does not hold. Whether it holds or not is a contingent fact beyond God's control. Moreover, we don't know whether or not this fact holds. Suppose that God is unlucky and transworld depravity holds. Then God cannot create any world that contains significantly free creatures but no sin. There are no volitional circumstances that God can actualize such that nobody sins, on those assumptions.

Now you may be asking this question instead. Suppose transworld depravity doesn't hold. Why, then, doesn't God create only volitional circumstances in which nobody sins. Well, two answers are possible for Plantinga. First, he might say that if transworld depravity doesn't holds, God would create only volitional circumstances in which nobody sins, but since we don't know that transworld depravity doesn't hold, this does not help the arguer from evil. Second, he might instead say that even if transworld depravity doesn't hold, some weaker condition might contingently hold. See my latest post.

Vlastimil Vohánka said...


"if transworld depravity doesn't holds, God would create only volitional circumstances in which nobody sins, but since we don't know that transworld depravity doesn't hold, this does not help the arguer from evil. Second, he might instead say that even if transworld depravity doesn't hold, some weaker condition might contingently hold."

This (and the post you mention) is really helpful, thank you.