Known as one of the founders of the “Chicago School” in Religious Studies, which defined the field's central path of scholarship during the last half of the twentieth century, Joachim Wach (1898–1955) was a German-born scholar of religion whose primary contribution to the field was the promotion of a method called Religionswissenschaft (literally, “the science of religion”). This method claimed that religion has an important socio-historical component that should be studied apart from theological or reductionistic explanations. Although the “scientific” study of religion has come to mean something different in contemporary scholarship—namely, questioning certain assumptions about the sui generis, or unique and irreducible, nature of religion often descriptive of older models of religion like Wach's—his work in the mid-twentieth century represented an attempt to move away from overtly normative demands and toward what was then considered a more empirical endeavor.

Wach taught at the University of Leipzig from 1924 to 1935 when he was driven from his university post by a then-growing Nazi influence. He emigrated to the United States, teaching at Brown University until 1945, and ended his career at the University of Chicago, where he also spent the last ten years of his life. Over the course of his career, Wach published numerous works, all of which were underpinned by the Religionswissenschaft method. These include Sociology of Religion (1944); The Comparative Study of Religions (1961); Types of Religious Experience: Christian and Non-Christian (1965); and Understanding and Believing: Essays by Joachim Wach (1968).