Robert N. Bellah, a distinguished sociologist of religion who sought nothing less than to map the American soul, in both the sacred and secular senses of the word, died on July 30 in Oakland, Calif. He was 86.

His death, from complications of recent heart surgery, was announced by the University of California, Berkeley, where he was the Elliott professor emeritus of sociology.

Throughout his work, Professor Bellah was concerned with the ways in which faith shapes, and is shaped by, American civic life. He was widely credited with helping usher the study of religion — a historically marginalized subject in the social sciences — into the sociological fold.

“Modern America has a soul, not only a body, and Bellah probed that soul more deeply and subtly than anyone in his field or his time,” Steven M. Tipton, a professor in the Candler School of Theology at Emory University, wrote in an e-mail on Monday....