Should we rid the world of carnivores if we could?
by Alexandre Erler
In a provocative piece for the New York Times, Jeff McMahan remarks that cruelty pervades the natural world: he stresses the vast amount of suffering and the violent deaths inflicted by predators on their innocent victims. He then invites us to consider a daring way of preventing such suffering and deaths: “Suppose that we could arrange the gradual extinction of carnivorous species, replacing them with new herbivorous ones. Or suppose that we could intervene genetically, so that currently carnivorous species would gradually evolve into herbivorous ones, thereby fulfilling Isaiah’s prophecy. If we could bring about the end of predation by one or the other of these means at little cost to ourselves, ought we to do it?” McMahan’s conclusion, which he describes himself as “heretical”, is that we do have a moral reason to desire the extinction of carnivorous species, and that it would be good to bring about their extinction if this could be done “without ecological upheaval involving more harm than would be prevented by the end of predation”.
As McMahan had anticipated, his piece has attracted quite a number of outraged comments. However, few of these can be said to offer objections that (excuse the pun) have any meat to them. Many actually raise points that McMahan himself considers, and replies to, in his essay. Among the weakest of these are the idea that implementing his proposal – even with the specific provisos he gives – would mean “playing God”, or acting “against nature”. Such lines of argument have a host of absurd implications: for instance, one might just as well use them to condemn morally innocuous practices like contraception or vaccination. They are therefore quite easily dismissed.
A slightly more plausible line would question whether McMahan’s proposal would really achieve its purpose: would we really reduce the total amount of suffering among nonhuman animals by abolishing predation? Would death after years of decay due to ageing really involve less pain for the animals concerned than the admittedly violent but comparatively short-lived attack of a predator? One might hesitate to give an answer here, though it still seems likely, in view of the multiple years that would be added to the lives of potential preys by the disappearance of their predators, that bringing about such an outcome would overall be in the interest of the former.
Yet another, more plausible objection, which McMahan himself considers, would appeal to the loss, both in terms of intrinsic and instrumental value, that the extinction of carnivorous species would represent. Wouldn’t his proposal mean depriving us of the joys of keeping cats and dogs as pets? (Dogs can admittedly survive without meat, but it's not clear that they can be strong and healthy without it.) And independently of the impact on our own well-being, wouldn’t the natural world be greatly impoverished and “watered down” if we brought about the extinction of carnivorous species to benefit the more “peaceable” ones?
I think there is something to this line of argument, and that McMahan dismisses it too quickly when he argues that the criteria for individuating species are largely arbitrary and that this casts doubt on the idea that species can have intrinsic value. Surely, if beautiful animals such as tigers or lions were to disappear completely, this would be a significant loss for the planet. Still, it is true that the badness of such a loss would have to be weighed against the benefit derived from the disappearance of predatory acts. And we might well conclude
that the interests of their potential victims outweighed the value, both intrinsic and instrumental, of having lions and tigers around. However, I think this objection still shows that if we could choose between the two alternatives presented by McMahan at the beginning of his essay (which he doesn’t make much
use of later on), we should choose to genetically modify carnivorous species to make them evolve into herbivorous ones, rather than causing their extinction, as at least most of the value under discussion would thereby be preserved. Assuming the idea of a vegetarian lion or tiger is by definition impossible, we
could at least produce very similar animals (“vions” and “vigers”?) that would have the beauty and majesty of lions and tigers without the cruelty. (I am not a utilitarian, but it seems to me that utilitarians can agree with this
suggestion, if only for the sake of promoting the well-being of people who love tigers and lions.) Furthermore, the complete disappearance of carnivores might actually not be necessary to put an end to the suffering and death caused by predation. Indeed, in vitro meat, an ethical alternative to meat grown in the lab, might soon be a reality, which would at least allow us to keep some of our favorite meat-eating pets – Doberman Pinschers and Rottweilers included. More generally, we could still have carnivorous species around provided that they did not need to hunt other sentient creatures.
Obviously, as McMahan is well aware, the most formidable obstacle to realizing his idea lies in the huge ecological imbalance that this might produce. Were we to sterilize all predators (which would already pose a major technical challenge), the population of herbivores would likely soon explode unless we could embark on a
large-scale program of population control that would be very difficult to carry out to say the least. At the level of concrete action, it seems much more urgent and realistic to focus on reducing the huge amount of needless suffering and death that we are inflicting ourselves on animals. Nevertheless, McMahan’s essay is a thought-provoking one, and makes a surprisingly plausible case for the desirability, if not of the complete extinction of carnivorous species, at least of a drastic reduction in their numbers together with the “conversion” of most of them into herbivorous, or at least non-hunting alternatives. The reactions to McMahan’s piece also reveal how deeply rooted the prejudice that we shouldn’t go “against nature” seems to be – a prejudice that arguably thwarts progress in a number of different domains of research today, such as the fight against ageing.