Good question...

"If a group of beings from another planet were to land on Earth -- beings who considered themselves as superior to you as you feel yourself to be to other animals -- would you concede them the rights over you that you assume over other animals?"
~ George Bernard Shaw, playwright, Nobel Prize 1925

Basically, would you want someone eating you? haha Thought it was an interesting quote and had to share. 

I found it on this site... http://choices.cs.uiuc.edu/~f-kon/vegetarian.html