Most people’s reasons for veganism fall into three categories: animal ethics, environmentalism and personal health. I will consider the basics known, and look at some more exciting ideas. They’re all minor reasons, but each of these has been my proclaimed reason for veganism at some point in time.
To annoy other people
There, I said it. I became vegan to annoy people. Some of my friends thought veganism was ridiculous, so this was the perfect reason to become vegan. 10/10 would recommend.
Not being able to argue why we eat animals but not people
Once I was eating vegan, I felt like I should only go back to eating animal product if I could convincingly argue why it is morally permissible to eat animals but not humans from the out-group. Moreover, the argument should not sound like it was made up after the fact. A reason that would convince somebody who had only 5 minutes earlier learned about the existence of the practice of eating animals.
[edit: I am aware of issues surrounding comparisons of human versus non-human slavery and oppression. Check back later for a post in which I attempt to responsibly summarize and review Aph and Syl Ko’s book Aphro-ism. Though if you are actually interested in this discourse, don’t take my white opinion on the book and read it yourself instead. The book is not very long and filled to the brim with perspectives you have never heard before.]
Moral gift economy
This is so much better than moral trade. You know that some people consider eating meat to be morally wrong, even if you don’t know anyone personally. As a gift to them, be vegan. Hopefully, this is a first step in establishing a moral gift economy, and people will at some point reciprocate by doing something you think is morally good but that they see no reason for.
Clean meat is coming soon
Veganism is low-hanging fruit for moral superiority, but clean meat will make this choice obsolete. For <10 years of effort, you can forever identify as morally superior. Take this last chance to score easy Virtue Points!
Modelling future you
In 30 years everybody has stopped eating slaughtered meat, and the first adults have grown up without ever eating a dead animal. Will people then consider eating meat to be as ghastly as we now think of slavery? I think they might. But then, will I be one of those people? In that case, it is smart to start being vegan right now. If you already know what you will think in the future, better start acting on it right now.
Choice under uncertainty
I am 98% sure that farm animals can’t suffer. But, supposing that they can, their lives would inevitably contain much more than 50 times as much suffering per pound of meat than how much enjoyment I get from eating meat per pound. In expectation, I consider eating animals to be a shitty thing to do.
Veganism as a computationally viable Schelling point
Is eating meat wrong even if the animals lived happy lives? Is it wrong to eat dairy and eggs? Even in small amounts? What about honey? What about animal byproducts?
You can put thought into each of these questions, and separately consider every bit of animal-derived food you might eat. But is that worth your precious thoughts, of which you have only 80 years of thinking to spend? I don’t think so. Veganism is easy to implement and communicate.