More thoughts on animal suffering

My recent article “Not just intelligence: Why humans deserve to be treated better than animals” elicited many thoughtful comments and plenty of debate, both on this blog and in Reddit. In this new post I have compiled some new thoughts that came up during the debate. To view the full discussion, please follow the hyperlinks.

Do animals have the ability to suffer?

I think that, strictly speaking, most animals species do not have the ability to suffer. These will include animals like corals, jellyfish, starfish, worms, clams, snails and insects that comprise millions of species with nervous systems so small that cannot possibly endow them with enough consciousness to suffer. In comparison, the species of chordates that can be said to suffer are a tiny minority. My work is in pain neuroscience, where we make quite nuanced distinctions between suffering, distress, pain and nociception. We know that many species have nociception, but we cannot infer from that that they feel pain, and even less that they suffer. Other show the same physiological signs of distress that we have (elevated levels of cortisol in the blood), but this doesn’t necessarily mean that they suffer. There are animals that clearly do not have nociception, pain, distress or suffering, like sponges. On the other end of the cognitive scale, it is clear that humans do suffer. At what point in the evolutionary tree the ability to suffer appears is not an easy question to answer.


Philosophers have been speaking of suffering as an absolute, something that exist in itself. In fact, neuroscience points out that suffering cannot exist without consciousness and is not independent of certain cognitive abilities like emotions and memory. An animal can only be said to be suffering inasmuch as it is conscious of this suffering, which links the problem of suffering with the “hard problem” of consciousness. This is because an unconscious animal would be just an automaton, something that responds to stimuli without having a subjective experience of those stimuli. As long as a being is self-conscious, including having extended consciousness, the life of that being has value of its own. So, like it often happens when we look at the living world, there is a gradient of minds between complete automatons and fully conscious human beings. Consciousness, and its attending capacities to suffer and be happy, develops gradually with evolution. So suffering, like consciousness, had to develop gradually during evolution. I doubt that there is a threshold, a hard line, with suffering on one side and not suffering on the other, so we have to wrap our minds around the fact that some animals have more capacity for suffering than others. Therefore, different species should be treated according to their mental capacities, which is, if you want, a hard form of speciesism. But it is what we do all the time, for example, when we kill the fleas that afflict our dog. Clearly, the dog has more moral standing in our eyes than the fleas.

In addition to consciousness, I think that suffering requires the presence of a self because otherwise the existence of the subjective experience of suffering doesn’t make sense. This is a variant of the problem of consciousness: do non-human animals have a self? That’s doubtful. Maybe apes and dolphins do, rats and mice probably don’t. But, again, that is highly speculative. Hence, there has to be a scale of suffering. In that scale, humans are capable of much deeper suffering (and much deeper happiness) because we can see ourselves as selves with an existence extending in time, so we not only suffer in the present, but we can see that we have suffered in the past and that we will suffer in the future. Without episodic memory and extended consciousness, animals do not have selves with that continuity in time.

An endangered fox in the California Channel Islands
An endangered fox in the California Channel Islands

Questioning the ability of animals to suffer doesn’t mean that scientists are looking for a justification to inflict pain on animals. Rather, here scientists face two different moral imperatives. The first is the fundamental dictate of science of looking for the truth unhindered by cultural and societal biases. This leads us to examine the questions of animal pain and suffering in an objective way. The second moral imperative is not to be cruel to animals that can potentially suffer. It is because of this and the cautionary principle that we treat animals like rats and mice as if they can suffer, even when we don’t know for sure that they can. However, we do know with absolute certitude that humans can suffer, which is an additional argument to put human suffering before putative animal suffering. Therefore, it is morally justifiable to use animals in biomedical research to alleviate human suffering, while at the same time taking all possible measures to minimize the distress of animals involved in research.

We need a definition of suffering for many practical matters and not just for animal research. Of course, we should treat animals, and even plants, with respect and not harm less for frivolous reason. But sometimes it is necessary to harm animals. There are many cases in which is necessary to kill animals to protect the environment – the case of pigs and goats in the California Channel Islands comes to mind. In those cases we need to balance two wrongs against each other: the suffering caused to the animals and the destruction of the environment produced by them, possibly including the extinction of some species. Animal research is another example: we need to use animals to find the cure for human diseases. When we look at the ethics involved in those cases, we need to carefully consider whether the animals involved do suffer or not, and how much weight we put on that suffering.

Feral pigs are an invasive species in the California Channel Islands
Feral pigs are an invasive species in the California Channel Islands

Suffering is not the only relevant issue in the animal research debate

Some animal rights proponents argue that mental abilities are a red herring because the only question that is relevant in the animal rights debate is whether animals can suffer. This is not true for two reasons.

First, this is in direct contradiction to what other animal rights proponents say: that animal rights go beyond the right to life and the right not to suffer, and also include the right to be free, the right not to be used for somebody’s else goals, etc. Then the question of whether animals have the mental capacities that enables them to know whether they are free or to care about whether they are being used are completely relevant.

Second, the way we treat a being is also determined by the intrinsic value we give to that being. For example, a species has an intrinsic value, so when a species goes extinct this means a terrible loss, and a deep moral wrong. Humans deserve respect not just because they suffer, but because of their intrinsic value. And that intrinsic value is based on our rich mental lives, our ability not just to suffer but also to be happy, to enjoy beauty, to find meaning in our lives. Therefore, mental capacities beyond the ability to suffer or to think intelligently are fundamental. It’s not just about humans, the same reasoning is used to give a dog more intrinsic value than the fleas that it carries in its fur.

But even if we accept the narrow framing that suffering is the only relevant question, suffering does not exist in isolation of all other mental functions. In particular, there cannot be suffering without consciousness because if there is no subjective awareness of the suffering, then it is not really taking place. Also, suffering, like happiness, acquires a deeper meaning for beings like us that can put it in a context of a life with a past and a future, in the middle of a society and a culture that creates a much richer context for any of our experiences.

Ultimately, the thing that worries me the most about the whole animal rights movement is how it has come to degrade the idea of what it means to be human by denying our rich mental abilities and making us equals to animals. Instead of elevating animals to human status, it degrades humans to animal status. Therefore, the animal rights movement is really a form of misanthropy, a radical anti-Humanism.

by Juan Carlos Marvizon

8 thoughts on “More thoughts on animal suffering

  1. Also, imagine some man is a serial brutal rapist, sadist and murderer. He is very intelligent, no doubts he has a rich mental life, he is able to enjoy life (and one of his greatest joys is degrading and killing people), he even has more complicted feelings and pleasures than you ever had, than you could ever imagine.

    Does his life has as much or more of intrinsic value than, for example, the life of your innocent child? If you measure the value of life by the mental richness.

    Would you save from a fire (if you can save just one person) him or some stranger who never killed any human? Given that this stranger is quite stupid compared to the serial killer?

    Let me guess, you will not save a person who is intellectual, but doesn’t value the suffering of others or enjoys it. Because the ability to value other’s lives and suffering is what really matters when you measure the value of a human.
    That’s one more your lie.

  2. Ok, then what about heavily mentally retarded or defected humans, that are not able to have mental lives richer than those of mouse or zebrafish? Do they have less intrinsic value for the author, than, for example, a normally mentally developed dog or monkey?
    If so, why not to use them as experimental objects, rather than monkeys? That would give much more accurate and applicable to other people results, cause experiments were conducted on real human organisms with all the human physiology.

    Would you vote for that use of mentally defected people?

    Let me guess. You will never support this. Because you lie. Because humans matter for you more than any other living beings simply because they are ones of your species. Simply because of speciecism. Simply because of fascism.

    1. If you see Juan’s original article:

      “An important corollary of the ideas proposed here is to utterly refute the “marginal case” argument. Thus, even when a human brain is damaged by disease, accident or old age, most of the properties that I have listed here remain because they are deeply ingrained in the way the human brain works. Theory of mind and extended consciousness appear early in human life and are the last things to go in a deteriorating brain. It takes coma to deprive us of them. A person may have a reduced intelligence or other cognitive disabilities, but s/he still has theory of mind, empathy, compassion, extended consciousness and all those human emotions. That is why when we encounter those people we recognize them as humans and we know we should treat them as humans. They are not animals and should never be treated as such. Intelligence is just a tiny part of what it means to be human.”

      The question is, why is speciesism wrong? And to equate it with fascism is a nonsense.

  3. Sincerely, cogently, sensitively expressed and reasoned — thank you. You leave open a wide field of debate while defending your position rationally. Ironically, we don’t see that enough in discussions of science.

  4. I think higher animals do have negative feelings due to pain, I mean it makes evolutionary sense to have negative emotions coupled with pain, or else the animal might ignore some serious injury. Perhaps not on such an existential level as humans, but negative emotions none the less. I mean, human babies and toddlers cry when they’re hurt. Cognitively, they’re not much more than animals, babies don’t have self awareness until one or two years, yet we know they feel pain since they’re human. How do we know they suffer in the same way as a mentally aware human? We can’t know exactly what is going on in their mind. We treat them better since they’re human like we are, but analytically, they fit your definition of diminished capacity to suffer, as babies don’t think about past or future pain, nor are they consciously aware of it like you and I. The negative emotions that come with pain are about the here and now, in the moment, but that moment is still unpleasant. I do believe that babies feel pain like you and I, and deserve to not have it callously disregarded, yet mentally, they’re about the same as many higher animals. The only reason people treat them better is because they belong to the species H. sapiens. Indeed, many nonhuman animals can anticipate painful stimuli in the future, look at classical conditioning. Even a slug learns to pull away from a water jet when it pairs it with an electric shock, no higher nervous system required. Many of these arguments get way too philosophical for me. They seem to focus on what one could be, or should be, all about their potential future to be. However, I focus on what one is right now. Make no mistake, I am pro-animal research, but I am also pro- 3 R’s and humane treatment including pain alleviation, not just suffering alleviation. However I still do not value humans over everyone else without solid scientific evidence for their higher capacity to feel pain and suffer than all other animals. If another species feels pain similar to us, and has negative emotions with it, I think they should get the same consideration to alleviating their pain. Think about it, babies don’t “suffer” anymore than the animals you described.

  5. I agree with much of what you write here, Juan. But again, the animal rights movement is not a monolithic entity. Rather it consists of all sorts of people and schools of thinking. It would behoove many among it to consider the points you make here. With others, it’s preaching to the choir. Those among the movement who genuinely think that all animals have exactly the same morally relevant interests as humans are a small minority. Still, it’s true that many lack a willingness to differentiate out of fear that offering one finger will lead to the hand being seized. I think this is understandable, and perhaps not even entirely wrong. Still, personally I value truth above all else, and hence instinctively agree with much of what you are saying.

  6. Hi Juan, the thing is vegans disagree with you that animals dont also have rich mental abilities, which means in there assessment its not degrading to humans to compare us to animals, and so when you say “Therefore, the animal rights movement is really a form of misanthropy, a radical anti-Humanism.” that is really a straw man argument. Vegans dont devalue humans rich mental abilities, they merely appreciate animals mental abilities.

    Now maybe we vegans are mistaken in our assessment animals mental abilities, but I feel your assessment is deeply affected by your speciesist bias, just like the Christians were affected by a similar bias against Darwin when he dared make a similar comparison. You can explain away cognitive bias, episodic like memory and empathy experiments on rats for example using the same behaviorist paradigm that is based on merely your own bias, but when any person sees mammals engaging in play or suffering pain our own theory of mind attributes to them consciousness, that the affective behavior they display really does mean they can feel. You are fighting a losing battle against not only a rational assessment of their abilities but humans intrinsic theory of mind, and one day I think people will look back on your biased and irrational approach that glosses over the cognitive abilities of animals as of something to be ashamed.

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