After reading some discussion on lemmygrad about veganism, I felt the need to share my thoughts in a separate thread, as comments weren't appropriate for the wall of text I'm about to throw.
Before we start, very important precision. This is not about environmental veganism, only about animal-liberation veganism. Consuming less animal products will be a lifestyle change we must anticipate to limit environmental destruction. This is about the moral philosophy of veganism and its contradictions with materialism.
Intro
Veganism is often rationalised under the form of a syllogism : it is immortal to kill and exploit humans, and non-human animals are equal to humans, therefore, it is immoral to kill and exploit non-human animals.
Now, I must say, if one is to contest the validity of this syllogism as a basis for veganism I encourage them to provide one since it could drastically change my point of view.
Like many syllogisms, there is appeal and validity to it until you question the premises. Let's review them under a materialistic lens.
Morality and materialism
The first premise is that it is immortal to kill and exploit humans. As leftists, we tend to wholeheartedly agree with such a statement, as it encapsulates our ambitions and dreams, however this cannot be pursued for a political manifest beyond utopian wishful thinking. Historically, killing has been justified as a high moral act whenever the one being killed was deemed worthy of death. The reason it is generally considered immoral to interrupt one's life is because humans simply have to collaborate to survive, therefore every society has developed a social construct that allows us to live as a social productive species. But whenever a war enemy, criminal, or dissident person is being killed under certain circumstances, the killing becomes justified, morally right.
As materialists, we don't base our interpretation of morality on a notion of some metaphysical, reality-transcending rule, and even less in relation to an afterlife. Morality is a human construct that evolves with material conditions. In that case, the relationship of human morality with non-human animals becomes more complicated than it seems. Humans do have empathy for other species but are also able to consume their flesh and products, a contradiction that has defined the construction of morality around non-human animals through history. This explains why it seems desirable for a lot of people to stop unnecessary animal cruelty while still wanting to consume their flesh, there is an act of balancing between empathy and appetite.
Equality of species and violence
Now you might have noticed that this framework is definitely human-centric. That brings us to the second premise, which is the equality of all species. By all means, it is absolutely outdated to maintain the idea of "human superiority" on all non-human species in the current times. As materialists, we should realise that humans evolved at the same time as other species, are dependent on the ecosystem, and that there is no fundamental variable that we have to consider as a criteria for ranking in an abstract "order of things".
That said, the equality of all species doesn't automatically mean the disappearance of inter-species violence. Firstly, we cannot stop unnecessary violence between fellow living beings that don't share our means of communication (unless we exerce physical control over them, but that's even worse). Secondly, there is an assumption that only humans possess the ability to choose to follow a vegan diet, which is extremely strange considering that it makes humans the only specie to have the capacity to be moral. Either non-human animals are excused for their chauvinistic violence against other species because they are seen as too limited, determined by their instinct, but it makes humans actually morally superior to other species. Or the animals must be held accountable for inter-species violence, which no vegan upholds, thankfully. Last option would be to consider that inter-species violence is part of life, which I agree with and think is the materialistic approach, but that means there is no reason to adopt a vegan diet.
Conclusion
So what does that let us with? Morality being a social construct with a material use in a human society, and humans being fundamentally empathetic, it is completely understandable that society will be progressing towards diminishing meat consumption to allow the minimization of animal suffering. But the exploitation of animals as means of food production doesn't have a materialistic reason to go away (unless we're talking about climate change, of course). The inter-species violence of humans against cattle and prey is part of nature, because we simply are a productive omnivorous specie just like any other.
This is mostly why I would discourage pushing people to abandon all animal products in the name of ethics. What should be encouraged is acceptance of every specific diet, be it religious diets, or animal-liberation diets. Strict vegetarianism must be a choice of heart that is based on profound empathy, not a superior moral choice or, worse, a moral imperative.
So, I'd like to preface this by saying I myself am vegetarian, and I respect anyone's choice to be vegan, or to be neither vegan nor vegetarian.
With that out of the way, I do have to disagree with the idea that harvesting animal products such as eggs and milk is inherently exploitive and that it can be a mutually beneficial relationship for both humans and livestock animals.
We must understand that in no way are livestock animals such as cattle, pigs, sheep, chickens, etc. a product of natural selection. The modern versions of these animals are the descendants of thousands of years of guided evolution by humanity. These animals cannot be returned to the wild, for they have not been wild animals in tens of thousands of years.
I bring this up to first illustrate that these animals' very existence is intertwined with ours. With this in mind, I'd like to conjecture that livestock animals have far better lives than most wild animals. They have access to guaranteed food, modern medicine, shelter, and protection from predation by other species. In return for these things, we receive products such as eggs, milk, wool, and more.
Secondly, many of these animals produce extra products as a result of the genetic manipulation. Cows make more milk than they need to nurse their young, hens produce eggs even when they are not making chicks, sheep grow wool to the point it needs to be removed to prevent complications.
I don't disagree that farming these animals on the scale we do today leads to a lot of unneeded suffering on their part, and tons of animal product getting dumped simply because it would be unprofitable to sell it. I'd like to think that in the process of scaling back production of these products, we can offer all of our livestock animals much more humane living conditions. The US doesn't need to produce 23.5 billion gallons of milk a year, especially considering how many cannot even consume dairy products.
Again, I respect anyone's dietary choices for whatever reasons they may have, and I do think there is much productive discourse to be had in regards to how we approach our livestock friends.
I would argue that breeding these animals to produce more than they need is a form of exploitation. Sure, on an individual level you can look at a modern cow and say she doesn't need all the milk she produces. But zooming out, you see a millennia old process of exploiting animals to produce more than they need. Breeding of defects is a thing that exists on a spectrum. Sure, we can't let these animals into the wilderness, but we can stopp breeding them.