Should a Modern Stoic be Vegetarian? by Massimo Pigliucci

Vegetarianism is a big deal, ethically speaking. It was put on the map in terms of public philosophy by utilitarian Peter Singer, with his landmark Animal Liberation, published back in 1975. In truth, utilitarians have been very clear on the subject from the beginning. The founder of the approach, Jeremy Bentham, famously said that when it comes to the treatment of animals “the question is not, Can they reason? nor, Can they talk? but, Can they suffer?” (in: Introduction to the Principles of Morals and Legislation, 1789).

What about Stoicism? A recent article by Jeremy Corter in Stoicism Today summarizes the situation as far as the ancient texts are concerned. I will not repeat Jeremy’s points here, since he does a superb job of it. After parsing several quotes from Zeno, Chrysippus, Seneca, Musonius Rufus, Epictetus, and Marcus Aurelius, he concludes (correctly, in my view): “Stoicism and vegetarianism are two separate philosophies. Stoic teachings never denounced eating animals and, in fact, often stated that animals were there for us to use. Musonius and Seneca are the only two Stoics we know of that were vegetarians, but neither cite any Stoic arguments for being so. Seneca cites Pythagoras and it would be safe to think that Musonius would have been aware of the same reasons.”

So why am I not ending the post here? Because of this, one of my favorite quotes from Seneca:

Will I not walk in the footsteps of my predecessors? I will indeed use the ancient road — but if I find another route that is more direct and has fewer ups and downs, I will stake out that one. Those who advanced these doctrines before us are not our masters but our guides. The truth lies open to all; it has not yet been taken over. Much is left also for those yet to come. (Letters to Lucilius, XXXIII.11)

I think vegetarianism is, in fact, one of those cases where the ancient road is not the best one, and we need to revise it. Full disclosure here: I am not a complete vegetarian, though I heavily lean that way. My eating habits can best be described as vegetarianism with the addition of occasional wild caught fish thrown into the mix (paying attention to whether the species in question is being overfished). I have never considered veganism seriously, even though the ethical argument there is at least as strong as the one for vegetarianism (though it’s not easy to be a healthy vegan, an issue I don’t want to get into here because it would distract from the main point). You could accuse me of hypocrisy, and I will respond that I’m trying to do my best, and that at any rate I’m doing more than a lot of other people. Never claimed to be a sage, never will.

As Corter himself recognizes near the end of his essay, this is of course a variation of the somewhat annoying generic question: “is X Stoic?” He is somewhat dismissive of the question itself, which – to be sure – is often abused on social media. But that doesn’t mean it isn’t a sensible question. Jeremy says “the Stoics don’t ‘approve’ of anything besides virtue … In short, it’s all indifferent.” Well, not exactly.

To begin with, virtue means nothing in a vacuum. Virtue is a propensity to engage in certain behaviors because that’s the right thing to do (as oppose to a vice, which is a propensity to engage in the wrong sort of behavior). One cannot be courageous, or just, or temperate, or prudent (phronesis) in the abstract. Virtue is considered by the Stoics the chief good because it can never, by definition, be used for ill. But it needs to be used for something nonetheless!

For what? Well, for handling the indifferents, which as we know come in two categories: preferred and dispreferred. This means that it is a bit too reductive and glib to say that the Stoics approve only of virtue because the rest is indifferent. The Stoics, for instance, opposed tyranny, and several of them lost their lives fighting it. Clearly, that means they disapproved of it! Seneca even approved of something as apparently neutral as rest and relaxation, as he makes clear in On Tranquillity of Mind, XVII.

So “is vegetarianism Stoic?” is a real question, and we need to find the answer not in the specifics of what the ancient said (since they are our guides, not our masters), but in the resources offered by the Stoic philosophical system as a whole. This approach is not unusual, being the same sort of exercise that modern Buddhists, say, or Christians, or Jews, engage in whenever looking at their own tradition for guidance concerning modern issues.

Indeed, the likely answer (in the affirmative) to the question of whether vegetarianism is Stoic is hinted at by Jeremy himself, near the end of his essay. He writes:

The Stoics felt that animals were there for human use, including for the use of food. This isn’t to say that the Stoics would have been in favor of factory farming or animal abuse. The Stoics thought that animals had souls, not like a human’s, but a soul nonetheless. Maybe I’m overthinking this part, but I’m suspecting that if they truly thought this, a Stoic would lean towards, if not protecting animals, at the very least not abusing and exploiting them.

Corter is not overthinking at all. He just should have pursued that line of thinking a bit further. We know a lot more nowadays about animal suffering than the Stoics did two millennia ago. Moreover, we have developed truly horrific standardized practices for the treatment of animals in quantities that the Stoics could not have imagined.

Just to give you an idea, these are the USDA statistics of slaughtered animals for the year 2008, obviously limited to the USA only:

Cattle: 35,507,500
Pigs: 116,558,900
Chickens: 9,075,261,000
Layer hens: 69,683,000
Turkeys: 271,245,000

I strongly suggest these numbers ought to disturb you, especially if you know anything about how all of this is actually done. And that’s without bringing into consideration additional factors that the ancient Stoics were not concerned with, like labor practices (generally speaking, horrible) and environmental impact (not at all good, to put it very mildly).

Given all this, I strongly suggest that modern Stoics should lean heavily toward vegetarianism, or at the very least endorse only humane practices of raising and killing animals, as it is done in a number of small, independently owned farms. The problem is that that model simply does not scale up to feeding billions of human beings, which means that, for practical purposes, Stoics should indeed be vegetarian.

But what about the idea – which the ancient Stoics surely did have – that animals and plants are here to satisfy human needs? That idea stemmed from the Stoic concept of a providential universe, understood as a living organism itself, endowed with the Logos, the capacity for rationality.

The problem is that modern science very clearly tells us that that’s not the kind of universe we exist in. Plants and other animals are the product of billions of years of evolution, just like ourselves, and so in no rational way can they be said to be here “for” us. Seneca, above, said that the truth lies open to all; it has not yet been taken over, as much is left for those yet to come. Well, two thousand years later we are still searching for a lot of truths, but we have found out a few more than in Seneca’s time. It is our ethical duty, therefore, to update our practices accordingly. Remember that one of the pillars of Stoic philosophy is precisely that the “physics” (i.e., all of natural science) should inform our ethics, so better knowledge of biology in particular should redirect the way we think about what is right and what is wrong when it comes to eating habits.

Jeremy argues that vegetarianism is an indifferent, and that “like any indifferent, it doesn’t make you a good or bad person.” I think that’s not the right way to look at it. Our diet is more properly referred to as the indifferent, but deciding what we eat and why is very much a reflection of our character, and therefore a function of how we exercise the virtues. As Epictetus put it in a different context:

What decides whether a sum of money is good? The money is not going to tell you; it must be the faculty that makes use of such impressions – reason. (Discourses I, 1.5)

Substitute “diet” for “money” and you can answer in the same way: reason. And reason – given contemporary scientific knowledge – very much tells us that we, as Stoics, ought to be vegetarians. Therefore, I’m going to redouble my personal efforts to follow this path and further reduce my intake of other foodstuff. I hope you will join me, to reduce both suffering in the world and our carbon footprint as a species. And Seneca adds, you’ll also feel better and think more clearly.


P.S.: very likely, there will be people who will read the above and argue the facts. I have neither time nor inclination to debate the science, so I will not respond. I have looked long and hard, as a biologist, into the various issues surrounding vegetarianism, and I have concluded to my own satisfaction that a vegetarian diet is: (i) better in terms of the ethics of animal suffering (though not as good as a vegan one); (ii) better for the environment; (iii) not supportive of horrible labor practices that are commonly engaged in by large agricultural corporations; and (iv) better for your health. If you are not convinced, that’s your prerogative, and clearly outside my control.


Massimo Pigliucci has a PhD in evolutionary biology from the University of Connecticut and one in philosophy from the University of Tennessee. He teaches philosophy at the City College of New York, and his latest book is How to Be a Stoic: Using Ancient Philosophy to Live a Modern Life. He blogs at How To Be A Stoic.

Author: Gregory Sadler

Editor of Stoicism Today

3 thoughts on “Should a Modern Stoic be Vegetarian? by Massimo Pigliucci”

  1. El vegetarianismo, y aún más el veganismo responden perfectamente a la ética estoica de “seguir la naturaleza”, y está demostrado, por sus características fisiológicas, que el humano es un animal de naturaleza frugívora. Por otra parte, la Stoa es panteísta y uno de sus principios fundamentales es la empatía universal, no solo la empatía hacia la propia especie, sino hacia TODAS las especies, consideradas como hermanas en el Ser, en la Mente cósmica o divina.
    (Se sabe que Marco Aurelio también era vegetariano). El tema está más desarrollado en mi libro “La Stoa, siglo XXIV”

    1. I embraced vegetarianism as a teenager with the motivating factor that our digestive system and molar structure was not designed to consume animal flesh but has accommodated the consumption of meat at a physical cost to our overall health. The suffering of animals, the planetary cost and implications regarding the environment are other factors that I have come to embrace. In addition trusting the commercial meat enterprise will be at your peril notwithstanding the unsanitary and inspection conditions at abattoirs . Vegetarianism seems like a reasoned and virtuous choice to make.

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