My reply to a person who brought up the Native Americans to justify eating meat:
American, or other people groups, ate and are eating animal products
because of cultural indoctrination, following the eating habits of our
ancestors and society.
a group of people, or a society, has done something for thousands of
years, does not in any way show whether something is morally right or
all agree that “unnecessary” animal suffering and death are morally
wrong. If that means anything at all, it must mean that we cannot
justify animal suffering and death by reasons of pleasure or
convenience. But what is our best justification for imposing suffering
and death on the 58 billion animals (excluding fish) we eat annually?
So the only justification we have is that which we agree cannot suffice. This is moral schizophrenia.
a vegan is easy, better for your health, and the most powerful way that
you, as an individual, can say “no” to animal exploitation.
Last sentences was a quote from Law professor Gary Francione, who also has written this excellent article: http://articles.philly.com/2009-08-14/news/24986151_1_atlanta-falcons-quarterback-vick-illegal-dog-dog-fights