Veganism

[Belacqua]

Since you never actually asked the question, your not getting responses that you consider appropriate seems to have you as its proximal cause.

I'll ask now: Is the property of being human what's morally relevant to whether it's impermissible or not to kill and eat a creature?

I think we could lay out the problem in a few steps. It might be clearer then.

1a) What are the traits which make us human beings? 

These might simply be anatomical, like DNA. But I suspect most people would want to include mental and/or behavioral characteristics. For example, natural language acquisition, the ability to imagine counterfactuals, the ability to reject (or attempt to reject) our instincts due to moral laws, the ability to feel empathy for people or animals we don't know (and it's easy enough to switch off this empathy, obviously, but a lot of animals don't have this). 

1b) To what extent do animals share any or all of these characteristics? 

2a) Does the fact that people have these traits make it bad to eat a person? 

2b) If an animal shares one or all of these traits, is it therefore bad to eat that animal? 

I think that vegans will point to certain traits that animals share with humans as a reason not to eat animals. For example we know that cows and pigs are pretty smart, have the ability to suffer, can feel affection, etc. So it's a pretty standard justification for vegans, to say that these traits which humans share with animals are the reason we shouldn't eat them. 

However I don't see any logical objective argument as to why it's bad to treat other people badly, or bad to treat "higher" animals badly. Often people say morality is based on empathy, but, as I said, it's really easy to switch off that empathy. As current events prove. 

At the moment I don't see any objective argument as to why we shouldn't treat "lower" animals badly. The only reason I can give is that I would like to live in a world which does its absolute best to minimize suffering. 

But I'm certainly open to better arguments than that -- it would be nice to find some. 

(By the way, have you ever tried the web site https://www.religiousforums.com/   ?) Several people who used to post here have moved over there, because the moderators encourage discussion, and it's possible to have a conversation that doesn't end in insults. Despite the name there are quite a few atheists posting there. You might give it a try.)