Appointed by President Obama as the White House “Green Jobs Czar” in March of 2009, Van Jones spoke at Yale Law School that spring. Somewhat sheepishly, in front of a packed auditorium of hopeful and bright-eyed law students, Jones admitted to bearing some bad news: The law degree, he noted, is in some ways a degree of the 20th century. The civic battles of the twenty-first century, he predicted, would be fought by those with MBAs.

Seventeen months later — that is, last week — when the CEO of General Electric criticized the United States for its failure to develop comprehensive energy policy and for the “stupid” structure of the electric industry, Van Jones’s prophecy appeared closer than ever to truth. The term “environmentalist” has certainly broadened from its once narrow euphemistic substitute for tree-hugger. Business leaders are now environmentalists — or they would be, if regulation were structured properly, if incentives were arranged as they ought to be, if externalities were only internalized. This is the logic underpinning a fourth major phase in U.S. environmentalism, and we had better hope it is sound logic.

Broadly and crudely, three phases define the U.S. environmental movement up until this point. First came John Muir, Thoreau and other like-minded transcendentalists and romantics with their slim tracts of florid prose. Then came the activists of the 1960s, inspired by passionate and compassionate scientists like Rachel Carson. Finally, a host of lawyers arrived on the scene for a protracted border delineation through legal and policy battles, kick-started by Richard Nixon in 1970 with the founding of the Environmental Protection Agency and a raft of today’s most progressive, well-known and effective environmental legislation.

Strangely, the maturation of the environmental movement parallels the maturation of a person: From the lofty and unbridled ideals of Muir and cohort, to a reactionary and rebellious adolescence, to a steady settle into legal pragmatism and political jockeying.

We are now entering a fourth phase of U.S. environmentalism, and it is the most pragmatic phase of all.

Many of the major nonprofit environmental groups focused on legal skirmishes over the past 40 years have become dismayed with a stagnant congress. Advocates feel stymied. A friend of mine who works in Washington, D.C. with a national environmental organization commented ruefully on the atmosphere after the failure of this year’s major climate legislation: “A lot of the people down here have basically given up. They don’t even come into work very often these days.” The hope that powerful legal victories might serve to orient the political compass and insulate it from false poles has faded.

But in its place is rising the celebrated collaboration between environmental and business groups. Jeff Immelt is replacing Gus Speth.

It’s no longer law time — it’s business time.

This is an understandable shift, and it is a pragmatic shift. If businesses are driving or exacerbating environmental problems, which they are, then partnership and incentives could help to minimize, stop or even reverse environmental degradation. But we must be careful not to feed the hand that bites us. That environmentalism and business interests are compatible, sometimes even complementary, is easy to discern. That environmentalists and business must work together is indisputable. But that streamlined, green and properly placed incentives will shift the thrust of corporations toward environmental stewardship does not readily follow from the first two concessions. Such efforts are laudable and worthy of pursuit, but they must be anchored by, drawn to a transcendental set of ideals. Efforts toward environmental protection can and should be pragmatic, but the motivation behind these efforts must be more than just pragmatic.

If the U.S. is to move to a more sustainable course, serious changes must be made very quickly. In recent years, environmental groups have been betting on business with the hope that proper market design will encourage proper behavior. This year’s Clinton Global Initiative, for example, has targeted the issue with panels like “Supply Chains of Opportunity” and “Market-based Solutions for Protecting the Environment.” (At this latter panel, the Lead Scientist of The Nature Conservancy talked alongside Walmart’s senior vice president of marketing.)

This is not an unjustifiable wager, but it is a delicate one. Vigilance is demanded to push business not simply toward something better, but toward something good.