I think that humans are part of nature.
The basis of the idea of unnatural
is a bit of a pickle, but I think it comes from analysis.
The sanction against murder is part of a complex of laws partly reflecting ideals of virtue, and partly pragmatic concerns about what order is required for a society to function as a tool for the expression of the human potential.
We tend to be concerned for our own survival, and figure the rest of life on earth is doing the same.
Our incredible power over nonhuman species is a fairly recent situation. I think we're still struggling to come to terms with it. Native Americans previously had no such power. They do now because they're Reebok wearing, Chevy truck driving consumers.
But before I finally condemn my own species, there's always some little thing that makes me hesitate. Wasn't it part of the old Jewish law that when you kill an animal, you must do it so the animal doesn't suffer unnecessarily? To me, that shows respect for life, and acceptance of the part we omnivores play in it.
Stuff has been posted on the this forum condemning the taking of animal life. To me, plants are just as alive, and just as worthy of respect when we take their lives to remake our own bodies. I don't know where the idea comes from, but it's with me: when I eat a carrot, the carrot's life becomes part of me. I'm part carrot.