One reason for this is the sheer diversity of the entities that make up this complex sector. Many people question whether it is possible to consider small neighborhood associations and well-financed business associations, tiny soup kitchens and massive hospital complexes, elite universities and small day-care centers as parts of a single coherent "sector."

An accurate view of the nonprofit sector has also been clouded by the myth that government and nonprofit organizations are in constant and fundamental conflict. In fact, one of the central realities of the nonprofit sector today is its mutually beneficial involvement with government.

To understand the American nonprofit sector and its role in promoting civil society, it is necessary to sweep away some of this mythology and look carefully at the actual operations of this set of institutions.

That nonprofit organizations play such an important role in American life is due in part to historical accident. American society came into existence before government appeared on the scene. Frontier settlers therefore had to find ways to provide needed public services for themselves, without the aid of a pre-existing governmental apparatus. They did so by joining voluntarily with their neighbors to create schools, raise barns and build public facilities, as well as many other things.

When Alexis de Tocqueville visited America in the early 19th century, he was struck by the proliferation of such voluntary groups. "Wherever at the head of some major undertaking you are sure to find the state in France or a person of wealth in England," he observed, "you will find an association in America." The deep-seated hostility to centralized authority that many immigrants brought with them from their homelands made a virtue out of this necessity, reinforcing the prevailing voluntary spirit and creating a presumption in favor of "do-it-yourself" approaches to solving public problems.

Although historical circumstances have changed considerably in the intervening 150 years, nonprofit organizations continue to play an important role in American life. More specifically, these organizations perform four crucial roles:

• The Service Role. Reluctant as they are to call government in to cope with a public problem until private solutions have been tried first, Americans tend to let nonprofit organizations lead the way in responding to critical public needs.
• The Value Guardian Role. The nonprofit sector functions as a "value guardian" in American society, and exemplar and crucial embodiment of a fundamental national value emphasizing individual initiative for the public good just as private economic enterprises serve as vehicles for promoting individual initiative for the private good. In the process, nonprofits foster pluralism, diversity and freedom.
• The Advocacy/Social Safety-Valve Role. Nonprofit organizations also play a vital role in mobilizing broader public attention to societal problems and needs. Indeed, they are the principal vehicle through which communities can give voice to their concerns.
• The Community Building Role. Finally, nonprofit organizations play a vital role in creating and sustaining what scholars have come to refer to as "social capital," i.e., those bonds of trust and reciprocity that seem to be pivotal for a democratic society and a market economy to function effectively, but that the American ethic of individualism would otherwise make it difficult to sustain.