The economic system that won the great ideological battle of the 20th century is facing a renewed challenge in the 21st. You can hear it in the passionate rhetoric of Pope Francis in Bolivia and see it in the crowds cheering socialist Bernie Sanders in New Hampshire. It even made its way to the privileged heights of Aspen this summer, where the New York Times’ David Brooks reports that columnist Anand Giridharadas accused NGO leaders of praising the rich “for all the good they do with their philanthropy” while never challenging them “for the harm they do in their businesses.”

The Friedmanites and Randians among us will dismiss such attacks as another misguided mutiny from the loopy left. The past two decades, they correctly point out, have delivered the greatest demonstration of capitalism’s benefits in the history of man. A billion people were lifted from poverty, largely because Chinese leaders abandoned the straitjacket of equality and allowed free markets to bloom.

But many smart business leaders sense that something bigger is afoot, and recognize that they ignore such public currents at their peril. Technology and globalization, for all their benefits, have widened the wedge between rich and poor. The financial crisis of 2007–08 has underscored the system’s roughest edges. The rising tide that once lifted all boats has caused a leak.

Prodded by socially conscious customers and idealistic employees, as well as a skeptical public, businesses are searching for new ways to prove capitalism’s power to rectify social ills. Whether it is John Mackey’s “conscious capitalism,” the “just capital” of Paul Tudor Jones, Michael Porter’s “shared value capitalism,” Lynn Forester de Rothschild’s “inclusive capitalism,” or Marc Benioff’s “compassionate capitalism,” the collective message is unambiguous: Your father’s capitalism needs some modification.

Fortune’s new Change the World list is our contribution to this trend. It is meant to shine a spotlight on companies that have made significant progress in addressing major social problems as a part of their core business strategy. It is based on our belief that capitalism should be not just tolerated but celebrated for its power to do good. At a time when governments are flailing, its powers are needed more than ever.

In doing this, we have enlisted the help of a small army of Fortune’s friends and mentors. The list includes some of the most thoughtful leaders we know in the corporate and nonprofit realms, as well as a number of scholars who bring both perspective and insight to the public discourse on business.

We are particularly indebted to FSG, a nonprofit think tank led by Mark Kramer and guided by Harvard professor Michael Porter, for investing many hours of their valuable time collecting and vetting nominations for the list. They have been pioneers in this effort, and we are lucky to have their assistance. While the editors of Fortune are ultimately responsible for the final list, we couldn’t have done it without their expertise and effort.

A couple of caveats: We have made no effort here to rate companies on their overall “goodness” or “social responsibility.” That’s a task beyond our competence. We recognize that these are large global companies with complex operations that may be ameliorating one great global problem even as they contribute to another (and we will continue to encourage our reporters to uncover the latter). Moreover, we acknowledge that some of these companies have undertaken the actions highlighted here in part to counter public criticism for past actions that are less than laudable.

Our point is simply this: Business in pursuit of profit still offers the best hope of addressing many of mankind’s most deeply rooted problems. Companies that are making genuine efforts to change the world for the better should be encouraged. The future of capitalism—and the future of mankind—depends on it.

To see the full Change the World list, visit fortune.com/change-the-world.

A version of this article appears in the September 1, 2015 issue of Fortune magazine with the headline “Doing well by doing good.”