Atheism is on the rise in America. The Pew Research Center recently found that about 6 percent of Americans identify as atheist or agnostic, while an additional 14 percent have no religious affiliation. One-third of adults under the age of 30 have no religious affiliation; these young adults espouse more liberal views on a host of human rights issues and are more likely to question the logic of corporatism and militarism. It’s surprising that few books have explored the correlation between nonbelief and the bedrock values of civil society. Imagine There’s No Heaven: How Atheism Helped Create the Modern World is a provocative, deeply researched and enlightening look at a wide range of historical figures—some fairly well-known, many not—whose battles against religion helped propel the tide of history as much as any mainstream church.

Although many readers might be familiar with the work and arguments of Sam Harris, Christopher Hitchens or Richard Dawkins, those writers generally have not focused on the origins of atheism. Stephens, a historian, journalist and professor of media studies at New York University, began his research for the book in 2003 and described it as challenging and fulfilling. “I wanted to show how moving beyond belief in a god contributed to what arguably were humankind’s two greatest accomplishments: the expansion of human learning and of human liberty,” says Stephens.

The book’s cast of characters, ranging over the course of centuries, is compelling. Among them: Jean Meslier, a village priest in 17th-century France who left behind four copies of a lengthy handwritten manuscript attacking all religion, and Charles Bradlaugh, elected to represent the largely working-class residents of Northampton, England, in 1880. Percy Bysshe Shelley, Simone de Beauviour and Charles Darwin are also thoughtfully discussed. Stephens writes primarily (though not exclusively) about European and American atheists, which left this reader more curious about the historical contributions of non-white atheists. “Had I had room for more discussion of contemporary atheist leaders, I would certainly have mentioned, for example, Jamila Bay, an outspoken African-American atheist,” Stephens says.

Still, he is able to cull some of the best and most intelligent scholarship on nonbelief. For instance, here’s a portion of an 1861 speech given by Ernestine Rose, a rabbi’s daughter from Poland who became one of America’s leading atheists in the 19th century:

The Atheist says to the honest, conscientious believer: Though I cannot believe in your God whom you have failed to demonstrate, I believe in man; if I have no faith in your religion, I have faith, unbounded, unshaken faith in the principles of right, of justice and humanity. Whatever good you are willing to do for the sake of your God, I am full as willing to do for the sake of man.

One of the book’s many strengths is its explanation of secularism. That word has come to mean more than just a rejection of religion and the separation stephens_cover of religion from the institution of government. “Early on in my research I came upon the philosopher Charles Taylor’s notion of a third kind of secularism,” says Stephens. “He defines it as the very modern condition in which it is difficult to believe naïvely in anything. This third secularism really helped me understand a situation—our situation—where most people have not entirely surrendered their belief in God, but the strength, the explanatory power and the demands of that belief have weakened to the point where it would hardly be recognized as religion by many of our ancestors.”

As someone who was raised by parents who encouraged him to question everything, Stephens is the ideal person to write a book that tries to answer some of humanity’s most vexing questions: In a more secular time, what determines our ethical code? In America, why do we still require our political leaders to be demonstrative in their public religiosity? Will we ever shed our Puritanical past?

“I hope the book also questions some of the easier answers to the problem of how we live without God,” Stephens says.

Christopher Carbone is a New York City-based writer. Follow him on Twitter.