The Effective Altruism Foundation provides the following as the 'Strongest Argument for Veganism'.

(1) We shouldn’t be cruel to animals, i.e. we shouldn’t harm animals unnecessarily.

(2) The consumption of animal products harms animals.

(3) The consumption of animal products is unnecessary.

(4) We shouldn’t consume animal products.

An obvious point of attack would be the notion of necessity.

a) It seems plausible that much if not most of the third world might not currently have sufficient access to an adequately nourishing vegan diet. The above argument would not seem to apply to such populations, other than perhaps in an aspirational sense; by suggesting it might be valuable/a moral obligation to enable such countries to reach a point at which consuming animal products becomes unnecessary.

b) 'Necessary' might encompass concepts other than nutrition/the sustenance of human life. For some people, the taste pleasure of meat and/or dairy may be deemed 'necessary'. Another person might deem that the pleasure of killing itself (such as via the hunt) might be deemed necessary, or that the hunt constitutes a sacred practice. However, the acceptance of such views might lead to a situation under which any subjective notion of necessity might be sufficient to render cruelty acceptable, including towards humans.

Are there any philosophers/philosophical works which address subjective notions of ethical/moral necessity, including perhaps how we decide what necessity entails? Does libertarianism deal with this topic in any detail? I'm particularly interested in any who explore this area in relation to animal welfare and in any who present robust philosophical justifications for speciesism, and more specifically for the cruelty we routinely inflict on animals for the purpose of obtaining animal products.

A determinist might state that our attitudes and actions are inevitable and that therefore so is cruelty; that cruelty is in a way 'necessary' as the product of all prior circumstances to date. This view (whilst persuasive) is perhaps of little value to the intricacies of this particular ethical discussion however or, (if it is wrong), might lead to inaction where action might in fact be the result of true agency.

Evolutionary psychologists might also have insight; I suspect not too dissimilar from that of determinists, in the sense that our lingering desire to eat meat and drink milk and wear skin is inevitable given the length of time for which these things have been necessary. More interesting however than the inevitability of such desire - and more pertinent to this stack - is why, given unnecessary cruelty to one another as humans is typically deemed undesirable, 'necessary' cruelty to animals might be afforded a lower threshold.

More succinctly:

'Are there any philosophical positions which seek to justify speciesism, in particular as it pertains to the 'unnecessary' cruelty we inflict on other animals?.

(Wikipedia summarises some arguments for and against speciesism - including those of Cohen, Williams, Staudenmaier, Scruton, Peikoff and Noddings - but these 'for' arguments don't tend to grapple with the 'unnecessary' aspect of human cruelty to animals, and the 'unnecessary' component of Effective Altruism's argument contributes greatly to its weight).

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    There's no point whatsoever in debating it. We just need people to develop non-animal foods, the same way we developed non-animal prime movers a hundred years ago, so that we don't have to sit behind horses' rear ends when we travel. It is an Engineering problem, so someone needs to get going on the solution instead of talking. Same with exploitive work, crummy housing, etc. That's the story the last 10 millennia, and I see no end to it. We'll tackle happiness when the other problems are solved. (Yes, completely dismissive statement. Your turn.)
    – Scott Rowe
    Commented Jul 27, 2022 at 14:02
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    I agree that it's an ancient issue, and that moving to a vegan lifestyle is a long way off for even the west, although there are very encouraging recent signs about the rising popularity of the vegan diet. As for there being no point in debating it though... sure it's largely debate (internal and external) which has led to the current gradual shift towards veganism. Debate will continue to play an important role as people question their choices more and more. I asked this question in order to try to steelman opposing perspectives so that they might be better engaged with.... Commented Jul 27, 2022 at 14:13
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    The fact that so many people continue to consume animal products despite likely agreeing with the argument in the OP hints at what a complex psychological issue it is (if not a philosophical one). Commented Jul 27, 2022 at 14:16
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    Ok. But I wouldn't call it veganism, or even a 'lifestyle'. I don't currently know anyone else (besides myself) who has saddled a horse or used a sailboat. Not doing those things is not a lifestyle. Its just... not needing "outworn buried age" (to quote an old guy) any more. It goes away when conditions change. Be the change you want to see in the world: be the person who creates appealing, affordable factory protein. If you build it, they will eat. No persuasion required.
    – Scott Rowe
    Commented Jul 27, 2022 at 14:19
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    I'm sure many people thought that using animals for labor was cruel, but until our buddy Henry Ford gave them an alternative, what were they supposed to do? Forget about talk. Act.
    – Scott Rowe
    Commented Jul 27, 2022 at 14:21

1 Answer 1


Necessity implies a goal. In ethics, a thing is never merely "necessary" — it's necessary in order or so that something be accomplished. It ISN'T necessary that you go to work. It's necessary that you go to work in order to get paid and to keep your job, itself necessary to getting paid. It ISN'T necessary that you keep breathing. It's necessary that you keep breathing so that you get oxygen to your brain and to the rest of your body. Getting paid, keeping your job, and keeping the oxygen coming to your brain are all goals.

In veganism, the limits of vegan practice are described as the limits of what is practicable, which is just another word for "necessary". "practicable" has an additional vague connotation for remaining in the realm of pragmatism and practicality, which "necessity" doesn't.

  • "What is necessary is never unwise." -Sarek
    – Scott Rowe
    Commented Sep 17, 2023 at 2:26

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