I can’t remember where I picked up this metaphor, though I’m quite sure I didn’t invent it: the free market as a natural ecology, totalitarian economies as machines.
I would add that today’s mixed, national economy attempts to be a walled garden, fertilized with the artificial nutrient of state-controlled money. And every time I read today’s headlines, I get the image of President Obama cruising around the garden in an enormous bulldozer, pruning its fruit trees with awkward swipes of the machine’s gaping bucket, weeding the just-budding perennials by gouging up great chunks of earth.