Should Vegans Eat Meat to Kill Fewer Animals?

By Angus Taylor | May 19, 2019

Pieter Bruegel the Elder, “The Harvesters,” 1565.

It is an unfortunate fact that no way of life, and no form of diet, can be entirely free of inflicting harm on others. Even veganism involves harm to animals – something that is implicitly recognized in the Vegan Society’s injunction to exclude exploitation and cruelty “as far as is possible and practicable.” Some sceptics claim that veganism is bad for the environment and bad for animal populations.1 A few have gone further and claimed that a vegan diet actually results in more animal deaths than some omnivorous diets.2

In a 2003 article,3 Steven L. Davis quotes Tom Regan as saying: “Whenever we find ourselves in a situation where all the options at hand will produce some harm to those who are innocent, we must choose that option that will result in the least total sum of harm” – which Regan calls the “minimize harm principle.” Based on a couple of empirical studies, Davis argues that, because of the large numbers of field animals killed in the production of crops, a commitment to this principle may require us to reject abstention from meat in favour of an omnivorous diet that includes grass-fed herbivores raised in “pasture-forage” systems. (Andy Lamey labels Davis’s position “burger veganism”.4)

In fact, Davis badly misreads Regan. Regan only mentions the “minimize harm principle” in order immediately to reject it.5 A utilitarian calculation of aggregate harm is incompatible with Regan’s own view, which centres on respecting the rights of individual subjects-of-a-life. Even so, Davis’s error is not fatal to his basic claim about harm, since it may still be the case, as he suggests, that an all-plant diet typically results in more animal deaths and more harm to them in general than some particular kind of omnivorous diet does.

Gaverick Matheny finds a large hole in Davis’s arithmetic.6 Davis has failed to take into account that much less land is required to feed a given number of people on an all-plant diet. When this miscalculation is rectified, says Matheny, a vegan diet is seen to result in significantly fewer animal deaths. Also, animals like mice killed by harvesters arguably suffer less harm before their untimely deaths than even grass-fed cattle, who are subject to various negative experiences over the course of their lives at the hands of humans.

In his 2007 article, Lamey takes a close look at the two studies upon which Davis relies.7 He finds, among other things, that Davis has greatly over-estimated the number of mice killed directly by harvesters; it turns out that most mice mortality results from predation by other animals after crop harvesting. The other study, involving Hawaiian sugarcane, where very different production methods are employed, does not seem to have much relevance outside the sugarcane industry. And all this does not factor in the human cost of animal agriculture, including the spread of disease, farm accidents, the toll on slaughterhouse workers, environmental degradation, and climate change.

Much of this is nicely summarized at one website, Animal Visuals, that also provides an interactive chart on estimated numbers of animals killed to produce the same amount of calories in different food categories.8

But can we really be confident about any of these estimates? Recently, Lamey and Bob Fischer have undertaken a broader look at the empirical and philosophical issues attending animal deaths in plant agriculture.9 They explain how difficult it is to arrive at accurate estimates of the numbers of animals killed; they also show that there are complex philosophical issues involved in deciding the extent to which we are morally implicated in these deaths.

A couple of studies they look at indicate that changes in animal populations in cultivated areas are the result of migration in and out of these areas and not the result of higher mortality in cultivated areas. But the fact that different species have different patterns of behaviour means it is not possible to simply extrapolate on the basis of data about one or two species.

The moral import of empirical evidence about animal deaths, difficult as such evidence is to come by, depends on answers to questions that are largely philosophical. Are we morally responsible for the death of a mouse killed by an owl after a harvester has removed the crop from a field? What if the mouse would not have existed in the first place if not for the shelter for mice provided by the crop? Is the short life of the average wild mouse on balance positive or negative in terms of experiences, and how does that affect our assessment of how harmful its death is? Should we factor in the benefit to the owl of feasting on the mouse? What about the mouse’s level of self-awareness and ability to plan for the future? Do some animals count more than others because of their greater cognitive capacities? Do insects count at all? Do we have an obligation to police the natural world in order to minimize suffering?

Many of the animal deaths in crop production are unintended. The doctrine of double effect applies to an action that has both a good and a bad effect. In standard form, it holds that the action is morally justified if the good outweighs the bad and if the bad effect – even when foreseen – is neither intended nor a means to the good effect. But some animal deaths in crop production are intended – e.g., through poisoning or trapping. Lukas Tank and Stephanie Thiel employ a version of the doctrine of double effect that distinguishes not only between intended and unintended harms but also between two types of intended harm: that intended to eliminate the difficulty presented by the unwanted presence of the victim and, by contrast, that inflicted in order to benefit from the opportunity presented by the presence of the victim. Unintended harms are normally easier to justify than intended harms, and within the category of intended harms, those aimed at eliminating difficulties are normally easier to justify than harms that are intrinsic to the agent’s goal. (If the crows feeding on a farmer’s crops disappear or are scared away, that’s fine with the farmer. But a pig or cow is a wanted victim; if the animal escapes, that’s a problem.) Tank and Thiel conclude that “producing meat seems to be morally impermissible in most contexts since the vast majority of the current meat production falls into the category of actions that are especially hard to justify.”10

The extent of harm done to animals in order to protect crops is not a given. Joe Wills discusses several ethical distinctions (including the eliminative/opportunistic one) that make killing farm animals for meat harder to defend than intentionally killing field animals to protect crops. Even so, he says, such distinctions cannot justify all current pest-control practices, some of which are excessive. He insists that lethal defensive measures ought to be used only as a last resort.11

Fischer and Lamey note some methods that already are reducing animal mortality, or that hold promise for the future. These include zero tillage or conservation tillage, controlling the height of vegetation between crop rows and in adjacent fields, contraception for pest control, greenhouses, and vertical or floating farms. A commitment to the core idea of veganism must not overlook the costs that attend growing the plants that feed us.

[Download article as PDF]

^ [1] Karin Lindquist, “The Least-Harm Fallacy of Veganism”
^ [2] For example, Mike Archer, “Ordering the Vegetarian Meal? There’s More Animal Blood on Your Hands”, The Conversation, December 15, 2011.
^ [3] Steven L. Davis, “The Least Harm Principle May Require that Humans Consume a Diet Containing Large Herbivores, Not a Vegan Diet”, Journal of Agricultural and Environmental Ethics 16 (2003): 387–394.
^ [4] Andy Lamey, “Food Fight! Davis versus Regan on the Ethics of Eating Beef”, Journal of Social Philosophy 38 (2007): 331–348.
^ [5] Tom Regan, The Case for Animal Rights (Berkeley: University of California Press, 1983), p. 302.
^ [6] Gaverick Matheny, “Least Harm: A Defense of Vegetarianism from Steven Davis’s Omnivorous Proposal”, Journal of Agricultural and Environmental Ethics 16 (2003): 505–511.
^ [7] Lamey, op. cit.
^ [8] Animal Visuals: Number of Animals Killed to Produce One Million Calories in Eight Food Categories
^ [9] Bob Fischer and Andy Lamey, “Field Deaths in Plant Agriculture”, Journal of Agricultural and Environmental Ethics 31 (2018): 409–428.
See also Andy Lamey, Duty and the Beast: Should We Eat Meat in the Name of Animal Rights? (Cambridge: Cambridge University Press, 2019).
^ [10] Lukas Tank and Stefanie Thiel, “The Doctrine of Double Effect and Killing Animals for Food”, Journal of Agricultural and Environmental Ethics (2019).
^ [11] Joe Wills, “The Intentional Killing of Field Animals and Ethical Veganism”, in Andrew Linzey and Clair Linzey (eds.), Ethical Vegetarianism and Veganism (London: Routledge, 2019).