Since you said you welcomed discussion, I have a few questions. I've been thinking about this topic occasionally, with some curiosity and some (mild) moral concern.
To prevent animals from suffering or dying.
It's not clear to me that my deciding to switch to a purely vegetarian diet would have the consequence of preventing the suffering or delaying the death of even one animal. (I can even think of relatively likely scenarios where it would make matters worse.)
How did you arrive at your decision? (To put it somewhat bluntly, did you first decide for emotional reasons to stop eating meat, and later rationalized it on grounds of alleviating the suffering of animals, or did you first work out that the decision would have effects of this kind and then implement it?)
I am horrified, when I think about it (which is not too often), by the conditions in which some "factory farm" animals are bred, raised and slaughtered. The suffering inflicted on e.g. pigs seems uncalled for, and other things equal I would prefer that they not suffer as much. I do try to buy free range when that choice is available, so to some extent that knowledge does affect my behaviour.
On the other hand, I suspect that "bringing my behaviour in line with my values" would call, if I really cared, for something more than only a change in my own dietary preferences. If I carefully worked out all the actions available to me that might have an effect on the situation, and ranked them by effectiveness, I'd be surprised if a change of diet came first.
Do you see that as the only option, or are there other things you do, besides not eating meat, directed at alleviating the suffering of animals?
How did you arrive at your decision?
The actual story: I was talking to a friend about the fact that meat eating, as a practice, inevitably causes animal suffering, and I realized that the benefit to humanity can't possibly outweigh the suffering caused, so I decided to stop participating in the practice.
I didn't do either of the two things you asked (act on emotion or on expected-utility calculation from my direct action), instead I tried to defend animal consumption as a general practice, failed, and concluded that I should stop.
Vegetarianism (if you s...
I have noticed that among philosophers, vegetarianism of one form or another is quite common. In fact, I became a vegetarian (technically a pescetarian) myself partly out of respect for an undergraduate philosophy professor. I am interested in finding out if there is a similar disproportion in the Less Wrong community.
I didn't request that this go into Yvain's survey because I want more information than just what animal products you do or don't eat; I'd also like to see nuances of the reasons behind your diet. There are a lot more shades than carnivore/vegetarian/vegan - if you want to be a vegetarian but are allergic to soy and gluten, that's a compelling reason to diversify protein sources, for instance. I'd also like to hear about if you avoid any plant foods (if you think they're farmed in a way that's environmentally destructive or that hurts people or if you have warm fuzzy feelings for plants, maybe). Here are some questions that come to mind: