. . . that gets us into trouble. It's the folks who like smoking who are the most likely to get cancer. It's the people who drive way too fast who are most likely to crash. The folks who want more salt on everything who develop high blood pressure. The carbohydrate addicts who get diabetes.

Now, before everyone shouts all at once, let me say that I know that each of those statements is a gross over-simplification. Some of them probably aren't even valid by that relaxed standard. But the point remains that it's not the stuff we don't like that turns out to be problematic, it's the stuff we do. The stuff we do a lot. The stuff we do too much, because we like it.

On an individual level, "like" boils down (in another gross over-simplification) to the good old pleasure principle. On a societal level, "like" translates to expect, or reward, or encourage based on shared precepts and standards. In both cases, what we "like" determines our default behavior pattern. What we do without thinking about it. Like reaching for that cigarette, or those potato chips, or fifth gear.

Two recent experiences brought me to this line of thought. The first was a discussion on the Green Schools listserv, in which an administrator at a boarding school in New Hampshire asked what definition of "sustainability" other schools were using. Most of the responses included variations on the Brundtland Commission wording, but that's not what struck me. What struck me was that after all these years, we're still trying to get people to understand what is, at its heart, a very simple concept: don't consume any resource at a rate faster than you can replace it.

On that basis, what's sustainable is pretty obvious. If you spend money faster than you can earn it, is that sustainable? If you add books faster than you can build bookshelves, is that sustainable? If you rob banks faster than you can spend the money, is that sustainable? The answer is obvious, so why is it so hard to get the underlying concept into people's minds?

The second experience was seeing the blockbuster movie "Avatar". On a cognitive level, it reduces rapidly to "Dances With Wolves meets Ferngully", but the movie isn't really about anything on any cognitive level. (In fact, what most struck me about the screenplay is that James Cameron took credit for writing it. If I'd written it, I'd demand that the fact not be shared with anyone.) Avatar, as an experience, is about the visual. I saw it in 3-D, and the effect was stunning. You know the graphics are computer-generated, and you just don't care. At all.

But back to what passes for a plot, the McGuffin is based on the (obviously Western material) invaders' desire for a resource, the extraction of which will entail destruction of the (clearly colonialized non-Western spiritual) indigenous civilization. The "treehuggers" (yes, that term appears in the dialogue) win, but it's the corporatists' motives we most clearly comprehend.

So Avatar plays, as any good colonialist fantasy will, on the disconnect between our expressed aspirations and our exhibited values. But it's our values which coincide with what we like, and our aspirations which express what we'd like to believe we'd like to like. Anything as abstruse as aspirations isn't likely to get us into trouble. Because if that were what we really liked -- what we were really like -- they wouldn't be aspirations at all. They'd be behavior patterns. Which sustainability clearly is not yet.