How can you separate them? How can you pick one? I was just down in the Gulf near Tallahassee (the oil hasn't hit yet) where earth, air, water, fire (a.k.a. sun) are so closely interrelated you cannot separate them --- think cypress swamp, salt marshes, rivers and their banks, not to mention gulf and shore. Think heat and humidity. Think creatures from sea grasses to alligators to brine shrimp to herons to longleaf pine. Not one thing exists in isolation. Yes, your mind can focus on one thing (my marine biologist friend down there had at one time been a leading expert on horseshoe crabs) but if you lose track of the relationships on which that one thing depends, you lose everything.