Bellah's "magnum opus", "Religion in Human Evolution" (2011), traces the biological and cultural origins of religion and the interplay between the two. The sociologist and philosopher Jürgen Habermas wrote of the work: "This great book is the intellectual harvest of the rich academic life of a leading social theorist who has assimilated a vast range of biological, anthropological, and historical literature in the pursuit of a breathtaking project ... In this field I do not know of an equally ambitious and comprehensive study." The book won the Distinguished Book Award of the American Sociological Association's Section on Sociology of Religion.