Thoreau, and his many heirs among contemporary naturalists and radical environmentalists, assume that human culture is the problem, not the solution.  So they urge us to shed our anthropocentrism and learn to live among other species as equals.  This sounds like a fine, ecological idea, until you realize that the earth would be even worse off if we started behaving any more like animals than we already do.  The survival strategy of most species is to extend their dominion as far and as brutally as they can, until they run up against some equally brutal limit that checks their progress.  Isn't this exactly what we've been doing?

For though we may be the Earth's gardeners, we are also its weeds.  And we won't get anywhere until we come to terms with this crucial ambiguity about our role - that we are at once the problem and the only possible solution to the problem.

First class of the year, Mrs. Voight [a biology teacher I had in the eighth grade, another dutiful demystifier, inveterate empiricist, and wearer of sensible shoes] announced, in a smug tone of voice striving for the matter-of-fact, that a human being was nothing more than a collection of chemicals that could be had from a biological supply company for approximately four dollars.  Why so cheap?  Because we were 95 percent water, with the rest consisting of relatively common forms of carbon.  I knew that day that, even if Mrs. Voight was right, she wsa not going to teach me anuthing I needed to know.
Everything that lives is 95 percent water.  Genius is 95 percent perspiration, 5 percent inspiration.  Success is 95 percent hard work.  Okay, I get it, but what about that 5 percent?  Tell me watermelon is 99 percent water and you still haven't told me anything interesting - like, what about the 1 percent?  Because chances are that's where you're going to find the watermelon…
I've had occasion to observe something else in good gardeners, a certain touch, an empathy for their plants, a sense of their soil more subtle and complete than any lab report's.  There are things they know I can't find in books.  It's the difference between the well-trained musician and the maestro, the water and the watermelon.  It's that unaccountable 5 percent.