To ask about the relation of science and religion is a fool's errand unless we clarify which science we are discussing, whose religion we are speaking about, and what aspects of each we are comparing. This Element sets the study of science and religion in a global context by examining two ways in which humans have understood the natural world. The first is by reference to observable regularities in the behavior of things; the second is by reference to the work of gods, spirits, and ancestors. Under these headings, this work distinguishes three varieties of science and examines their relation to three kinds of religion along four dimensions: beliefs, goals, organizations, and conceptions of knowledge. It also outlines the emergence of a clear distinction between science and religion and an increase in the autonomy of scientific inquiry. It is these developments that have made conflicts between science and religion possible.