Sep 20, 2010

Is our world better off without carnivores?

Jeff McMahan has a nice piece in the NYT philosophy blog arguing that we’d have a better world if could eliminate (in some suitably humane fashion, like clever genetic engineering) the carnivores. I’ve heard arguments like this before, from non-philosophers, but this is the first time I’ve heard a philosopher making it. I think the line of thought has some intuitive appeal. If eating meat is morally bad because of the animal suffering that goes along with it, then isn’t that true whether or not it’s humans doing the eating? Isn’t a lion eating a gazelle morally on par with my eating a hamburger, since both involve causing an animal to suffer? If we grant this parity, moral arguments against vegetarianism amount to moral arguments against the existence of carnivores. We should take steps to reduce meat-eating by humans, as well as by non-human animals, because doing so means reducing animal suffering. That, anyway, is the line of argument McMahan is proposing.

I’m not quite sure that the argument goes through. It seems to require as a premise that a world with no carnivores at all contains less animal suffering than a world that has non-human carnivores but no human carnivores. That is, eliminating carnivores from the animal kingdom would result in a world with less animal suffering.

I find this implausible. There isn’t much difference in suffering, and thus, in moral badness, between an herbivore being eaten by a carnivore, and an herbivore being out-competed by another herbivore, or dying a natural death due to disease, injury, etc. In fact, we might think there’s less suffering involved in being eaten than in slowly starving by being out-competed, or in freezing to death in a cold winter. And, if the suffering from predation isn’t greater than the suffering without predation for a given animal, then McMahan has to show that fewer animals suffer in a world without predation. But that seems false, given plausible assumptions about population dynamics.

Let me end on a positive note. McMahan’s piece is rich and challenging, raising a lot of important issues. He questions, for example, whether ‘species’ is a morally relevant category: “The claim that existing animal species are sacred or irreplaceable is subverted by the moral irrelevance of the criteria for individuating animal species.” With this, I agree; we talk about animal species as a convenient way of carving up nature and organizing our biological knowledge, but it doesn’t seem terribly important to morality. (This isn’t to deny anything about human exceptionalism; I would think that if anything makes humans special morally, it’s not something that depends essentially on our species membership. That is, you can still think humans have intrinsic dignity even if you don’t think that that dignity depends on our being a member of Homo sapiens.) I heartily recommend reading McMahan's rewarding article. 


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  2. I think you're right about the crucial premise, but doesn't McMahan consider this and build it into his argument that we would need to work this out before the plan would be feasible?

  3. Anonymous, I'm not so much talking about feasibility here (which McMahan does consider) as about the inherent limitations, regardless of how clever we are. Simply put, the life of an herbivore in a world without predators does not contain any less suffering than in a world with predators. If anything, it contains more, even if we're not in a Malthusian population crash scenario.

  4. Matt,
    Again, that sounds like feasibility to me. You seem to claim that it is impossible, in principle, to prevent an overpopulation problem. Really? Controlled breeding wouldn't do the trick? Again, McMahan is certainly in sci-fi land, but he will admit as much.

  5. Anonymous, thanks for your comments. Let me put the point this way to see if it helps. Let's assume that the number of herbivores in the world is currently X; and let's assume that in McMahan's envisioned world without human or non-human predation, the number of herbivores is also X. He assumes that the second world contains less herbivore suffering. That seems false, as herbivores will still be mortal, will still get sick and die from natural causes, etc. None of this depends on overpopulation, as I've stipulated that the herbivore population is unchanged.

  6. I imagine there might even be more "suffering" in a sense. You might end up with more herbivores than before, and if the amount of suffering is roughly proportional to the number of animals, then you could end up with more suffering.

    I find the ethical goal of reducing or eliminating suffering to be an odd one. For one thing, it's not very well defined. Is a person running a marathon suffering? Should I try to prevent him from doing so? Wouldn't the surest way to reduce suffering be to gradually eliminate all life on earth (e.g. through population control), since presumably to live is to suffer?

    It seems that suffering often serves a purpose. We actually deliberately inflict suffering in order to bring about a good end, in many cases. E.g. we punish wrongdoers (whether it be "time-out" or capital punishment, there will be some suffering involved.) There's even the saying "no pain, no gain."

    What if we changed the word "suffering" to "unpleasantness"? Eliminating unpleasantness sounds a little too much like Brave New World for my tastes.

    The vegetarians and suffering minimizers should meet Paul Simon: "I have no need for friendship. Friendship causes pain."


  7. McMahan agrees that suffering can be instrumentally good, if it leads to the right kind of positive outcome, though he thinks even in those cases it's intrinsically bad. I find this a strange combination (one thing being at once intrinsically bad and instrumentally good). Also, for independent reasons, I tend to think of pain and suffering as, at least in some cases, not intrinsically bad. I might post something about this in the future.

  8. Matt,
    "I find this a strange combination (one thing being at once intrinsically bad and instrumentally good)."
    I'd like to hear more about this. This doesn't seem controversial at all. Even Plato recognized the possibility. Think of going to the dentist. It hurts--intrinsically bad. But it prevents much more pain the future--instrumentally good.

  9. Anonymous,

    I have suspicions about thinking that there can be intrinsically harmful experiences or events. I tend to think of harm as a matter of how something fits into the whole scheme of one's life; there won't be much sense in talking about the value or disvalue of something to an individual in isolation from the broad context of his life. That's why I find intrinsic badness and instrumental goodness a strange combination. There's a lot more to be said about this, of course, and I appreciate your comment.

  10. Thanks for this post. I'd just like to point out that this is an issue that is getting growing attention. Here are some other papers that have dealt with it:

    Yew-Kwang Ng, 1995, "Towards welfare biology: Evolutionary economics of animal consciousness and suffering", Biology and Philosophy, available with subscription here:

    Tyler Cowen, 2003, "Policing nature", Environmental Ethics, available here:

    Charles Fink, 2005, "The predation argument", Between the Species, available here:

    Alan Dawrst, 2009, "The Predominance of Wild-Animal Suff ering over Happiness: An Open Problem", Essays on Reducing Suffering, available here:

    Oscar Horta, 2010, "Disvalue in nature and intervention", Pensata Animal, available here:

    The argument is also presented in Steve Sapontzis, 1987, Morals, Reason and Animals, Philadelphia: Temple University Press.

  11. Thanks for the references, Oscar.