Colleges and universities have long offered majors in religion or theology. But with more and more people now saying they have no religion, one college has decided to be the first to offer a major in secularism.

Starting this fall, Pitzer College, a small liberal arts institution in Southern California, will inaugurate a department of secular studies. Professors from other departments, including history, philosophy, religion, science and sociology, will teach courses like “God, Darwin and Design in America,” “Anxiety in the Age of Reason” and “Bible as Literature.”

The department was proposed by Phil Zuckerman, a sociologist of religion, who describes himself as “culturally Jewish, but agnostic-atheist on questions of deep mystery.” Over the years he grew increasingly intrigued by the growth of secularism in the United States and around the world. He studied and taught in Denmark, one of the world’s most secular countries, and has written several books about atheism.

Studying nonbelief is as valid as studying belief, Mr. Zuckerman said, and the new major will make that very clear.