TODAY'S WORLD IS full of Goliaths – big, brutal hulks determined to have things their way – and a bit short on Davids, the slight but doughty figures who accept the long odds and beat them. I speak, of course, not literally of people but of business endeavors – in particular, in this space, of coffee endeavors.

I would never have believed, a decade ago, that Starbucks would succeed in anti-chain San Francisco. But Starbucks did succeed here, so much so that another giant Seattle coffee company, Tully's, soon arrived to join the battle by buying up the locally grown Spinelli Coffee Co. Now there are Starbucks and Tully's all over the place, as if this were Dallas or Omaha: a pair of leviathans struggling for market share. Starbucks' coffee, meanwhile, has become both bland and ubiquitous, with cutesily named categories supplanting the old emphasis on varieties and roasts, and placement in supermarkets and on airplanes. Tully's seems to differ only as a matter of scale, and no doubt its busy marketers are scheming to straighten that out.

And David? That would be NaS, which opened its first two Financial District shops last May, within a few blocks' walking distance of a dozen Starbucks outlets, not to mention some Tully's and a scattering of Peet's. The name stands for "natural and superior," and it means NaS deals only in organic, fair-trade coffee – coffee grown and marketed, in other words, by means that sustain not only the earth but the farmers who work it.

The people behind NaS, Nana Kim and Steve Hahm, believe sound business practices can also be socially responsible. Are they right? We had better hope so, for the alternative is a world eventually laid waste by devouring, short-sighted greed. The young are more concerned about this apocalyptic prospect, on balance, than older people; they will be a part of the world longer, and if only for that reason are more likely to steer a course that will not cause the globe to be despoiled by the time they're 50. Idealism need not be quixotic; the most effective idealism, in fact, reflects enlightened self-interest, a principle even Adam Smith would understand.

The real crunch for NaS is not getting started. Although that is always a difficult business, there is a sizable market for socially responsible consumption in San Francisco. The real crunch will flow from NaS's likely success, when those nearby Goliaths from Seattle either start to co-opt the market by doing what NaS is now doing or one of them offers simply to buy it up. It's hard to say no to Goliath.