Most of us believe that eating meat is natural because humans have hunted and consumed animals for millennia. And it is true that we have been eating meat as part of an omnivorous diet for at least two million years (though for the majority of this time our diet was still primarily vegetarian). But to be fair, we must acknowledge that infanticide, murder, rape, and cannibalism are at least as old as meat eating, and are therefore arguably as 'natural'--and yet we don't invoke the history of these acts as justification for them. As with other acts of violence, when it comes to eating meat, we must differentiate between and