How would you define “dirt?” One answer is “dirt is stuff out of its proper place.” Soil in your garden isn’t dirt: it becomes dirt when it’s on the living room floor. Saliva in your mouth is not dirt: spit on the ground it’s repulsively dirty. Inside the body, in its proper place, blood is not dirty. Outside the body it’s alarming and unclean. Your fingernails, on the ends of your fingers, are not dirt: fingernail clippings, sitting on the table, are repulsively dirty. They have not changed in any way–same material, same level of germs as when they were on your fingers, but now they’re disgusting. Dirt is matter out of place.
Cultural anthropologists argue that human thought consist mostly of taking the random, amorphous stuff off the world and “placing” it, forming it into categories: “these are vegetables, these are fruits, these are minerals, this is a mammal, that’s a fish.” These categories can appear scientific, as when we assign a species to an animal or plant. Or they can appear moral or religious, as when we say “this is good, that’s bad; this is sacred, that’s profane.” But thinking mostly consists of making categories: clean and unclean, taboo and acceptable, edible and not edible; negro and caucasian and asian.
But no human classification scheme can entirely comprehend the world. There are always things that don’t fit neatly into either category. Anthropologists call these “boundary transgressing animals.”
Imagine a society that has divided the world of animals into three categories; those that walk, those that swim, those that fly. Even though it’s pretty good: it fits most animals.
Then imagine you are walking along the beach one day and a lobster crawls out of the water. The lobster would be, in this society a monster: it walks in the land of the swimming. People who lived in the society I described would be unable to wrap their minds around it–they would have no category for it.
A monster, by definition, is always a boundary transgressing animal. Think of all the great movie monsters–they are always half this and half that, they change their shape, they’re half dead and half alive, half human and half animal. They cross the boundaries that we use to make sense of the world.
Anthropologists argue that boundary transgressing animals are generally either monsters or sacred, magical beings. In some societies, hermaphrodites, people born with ambiguous genitalia, evoke a strong feeling of discomfort and unease: they violate one of our fundamental categories for understanding ourselves, “male” and “female.” In other societies, hermaphrodites are regarded as magical holy beings, because they bridge the worlds of male and female. Jesus Christ, in anthropological terms, is a boundary transgressing animal: both God and human, capable of magic.
We’re not always aware of the fundamental categories we use to make the world sensible. We grow up with them: thought itself is formed around them. When something “creeps you out,” makes you uneasy or disgusted, you are probably looking at something that violates your fundamental categories. Boundary transgressing animals are always the site of intense fascination and controversy. Racially mixed people, for example, are often depicted in film and fiction as evil or magical or tragic. Pop stars can make whole careers out of being boundary transgressing animals: Lady Gaga is a perfect example recent of a career path mapped out earlier by Madonna, Prince, Elvis, Liberace, or Mae West. Ambiguous sexuality, ambiguous race ambiguous gender; disrespect for standard categories of dirty/clean/sacred/taboo. It’s never clear if boundary transgressing animals change the way we think, or if they only make the fundamental categories stronger. Probably it’s both.
Historians like the “boundary transgressing animal” because when you see what disturbs people, what makes them irrationally uneasy, you are probably seeing the fundamental categories they use to make the world sensible and meaningful.