Politicians want their votes, pollsters seek their opinions and preachers love to speak for them all - the Protestant evangelicals of America. Yet not only is this Bible-believing force of 40 million to 60 million Americans hard to define from without, evangelicals have struggled for a half-century to define themselves from within.
This is the theme of Jon R. Stone's "On the Boundaries of American Evangelicalism," which eschews old metaphors about the evangelical "family," "mosaic" or "kaleidoscope" as useless in pinning down this dynamic social group. Mr. Stone applies instead an analytical tool called "boundaries," used by sociologists to explain how a group defines itself in terms of insiders and outsiders. The approach, which may seem like yet another academic whimsy, is helpful in getting a grip on groups that have shifting relations with close social neighbors.
"Evangelicals have a stake in defining their label, since by it they likewise define the boundaries of their own community," Mr. Stone writes. As long as their boundaries with both "modernity and rival religious communities" are intact, he goes on to show, the content of evangelicalism can change. In laying out this framework, the author generally succeeds in retaining enough storytelling, as any good history demands, to keep the book flowing. It is a story of internal conflict, hope of national unity and a modern-day breakup.
The conflict began when, in the 1920s, Protestantism split between liberals who worked with modern society and fundamentalists who condemned "the world" and retreated to save souls. From this fundamentalist family emerged a group that disliked the negativity and isolation of their brethren, and they took on the moniker "evangelicals." They harked back to the previous century, when evangelical meant fundamentalist beliefs but also efforts to reform society and serious scholarship. Even today, "evangelical" is synonymous with being historic, orthodox, centrist -in effect, the good guys.
Modern evangelical identity was born, Mr. Stone says, to draw a boundary against the negative fundamentalists on one side and the modernist Protestants on the other. This central path was staked out by people like Carl Henry, the first editor of Christianity Today, and evangelist Billy Graham, as well as organizations such as the National Association of Evangelicals, formed in 1942.
Mr. Stone uses Christian press editorials and speeches as his …