Haven’t you watched people arm themselves to the teeth just to stick a few pansies in the ground? Or avoid the great outdoors entirely, with a wrinkled nose, because it’s muddy? Certainly, avoidance of dirt is the central obsession in approximately 100 million American kitchens, and the supermarket shelves are groaning with products designed not just to clean our persons and houses, but to well-nigh sterilize them.
There are costs to being too clean. Not only are you unlikely to garden, one of the theories behind the rise in allergic diseases like asthma is the "hygiene" theory: our houses are so sanitary that our immune systems are never properly primed in childhood by real germs and instead wind up over-reacting to harmless allergens.
So why are we so obsessed with cleanliness? My favorite explanation comes from Adrian Forty’s terrific book Objects of Desire: Design and Society Since 1750. We dislike dirt in part because advertising agencies sold us on the idea that we should dislike it. It was their job in the early years of the 20th century to market the first electric appliances, which were a lot more expensive than elbow grease and not a whole lot more efficient. So, some marketing geniuses hit upon this idea: emphasize the superiority of the cleaning job they do. Scare houseswives by telling them their houses are "haunted" by germs that can only be gotten rid of by purchasing an electric vacuum and a jug of Lysol. Convince them to replace their comfy, woody Edwardian kitchens and baths with gleaming white tiles, not because the tiles are easier to keep clean–the opposite in fact–but because they show the dirt and encourage one to scrub.
So, here we are, "haunted" people who can’t tell the difference between loam and disease and who don’t recognize that good health resides in working the soil. And that fear of the soil makes us both sick and silly.