It is well-documented that certain animals will eat other members of their species, and other creatures will not. Few higher species actually hunt and kill their own kind for food, but some will consume dead brethren when given the chance. (There is one notable exception: quite a number of terrestrial creatures will, without a moment's moral quavering, consume the children of a rival genetic clan. From the standpoint of natural selection, the reduction in overall numbers of individuals is outweighed by the tendency for weaker members of the species to be weeded out early in their lives. Naturally, devouring the progeny of dissimilar genetic group is a handy way to eliminate the competition for one's own offspring while getting a good meal in the process.)

There is good reason to believe that most creatures possess a hardwired genetic tendency to avoid consuming the flesh of their own species. In humans, this tends to manifest itself through cultural mores that excoriate cannibalism. While you might argue that cultural rules are entirely separate from genetic impulses (often created in an attempt to control our genetic animal heritage, rather than codify it), the fact that the overwhelming majority of human societies discourage cannibalism suggests that there is an underlying external factor that facilitates this common belief. Perhaps, the religious person might argue, this is not the effect of a gene but the voice of the soul, crying out against the abomination of eating human flesh.

Some anthropologists have contended that there are no truly cannibalistic societies. They claim that every supposed example of sustained cannibalism by a group of people has turned out to be a myth. Such images are indeed powerful and enduring. Vampires and their many variants show up in the traditions of many diverse cultures. In Senegal, there were spiritual cannibals who devoured people from the inside out, eating up little bits of their soul until the afflicted individual lost their will, sickened, and died. Some anthropologists believe that cannibalism is just a label that has historically been applied to one's enemies to show how inhuman they really are.

Friends who have lived in certain parts of the world disagree.

It is not unheard-of for humans to consume other humans, although it is typically done at the margins of society. In one movied example, survivors of a plane crash high in snowcapped mountains ate their dead fellow travelers in order to stay alive. A few serial killers in recent history turned their nations' collective stomachs by eating the bodies of their victims. Amateur vampires get together on a Saturday night to lap up a little blood vented by a willing member and talk about the latest Ann Rice book.

I am researching an article about human cannibalism for Omline. Specifically, I've being poking around in search of people who eat cast-off body parts: amputated digits, surgically extracted organs, placentae, and so forth. The underlying moral question for me is whether, as a vegetarian, it is morally justified for me to eat the flesh of a consenting adult who was not killed for food. More soon.