Ask a hundred people what they think religion is and you'll probably get a hundred different answers. However, to study religion we have bring together more general ideas about what religion is and what it does.  This film, with Professor Eileen Barker of the London School of Economics, explains and illustrates the two dominant sociological approaches to religion: substantive, with a focus on the salient features of religion and functional, where the focus is on what religion does for the individual and society.