My parents are both vegetarian, and have been since I was born. They brought me up to be a vegetarian. I'm still a vegetarian. Clearly I'm on shaky ground, since my beliefs weren't formed from evidence, but purely from nurture.

Interestingly my parents became vegetarian because they perceived the way animals were farmed to be cruel (although they also stopped eating non-farmed animals such as fish), however my rationalization for not eating meat is that it is the killing of animals that is wrong (generalising from the belief that killing humans is worse than mistreating them). Since eating meat is not necessary to live, it must therefore be as bad as hunting for fun, which is much more widely disapproved of. (I'm not a vegan, and I often eat sweets containing gelatine, if asked to explain this, I would rationalise that eating these thing causes the death of many fewer animals than actually eating, like, steak).

But having read all of Eliezer's posts, I now realise that I could have come up with that rationalisation even if eating meat were not wrong, and that I'm now in just a bad a position as a religious believer. I want a crisis of faith, but I have a problem... I don't know where to go back to. There's no objective basis for morality. I don't know what kind of evidence I should condition on (I don't know what would be different about the world if eating meat was good instead of bad). If a religious person realises they have no evidence they should go back to their priors. Because god has a tiny prior, they should immediately stop believing. I don't know exactly what the prior on "killing animals is wrong" is, but I think it has a reasonable size (certainly larger than that for god), and I feel more justified in being vegetarian because of this. What should I do now?

Footnote: I probably don't have to say this, but I don't want arguments for or against vegetarianism, simply advice on how one should challenge one's own moral beliefs. I've used "eating meat" and "killing animals" interchangeably in my post, because I think that they are morally equivalent due to supply and demand.