If you and a friend were on an island, there is no food, plenty of water, and a possible chance of rescue. With you, you have a pig. Do you eat the pig, or wait and possibly die of starvation, or is all life equally sacred?
The second scenario, the only other possible food on the (ever so plausible:P) island, are less anthropomorphised, fish. Do you eat the fish, or starve waiting for rescue?
Another possible option of course is eat your friend first, but that's kinda creepy.
I don't mean this post to cause any bad feeling by the way, as vegetarianism, (and possible cannibalism) is an emotive subject for some people.
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Nothing lasts but nothing is lost