Prospect Magazine has published a series of letters between Richard Swinburne and Daniel Dennett regarding the existence of God and the historical origin of religious belief, following the publication of Dennett's new book Breaking the Spell: Religion as a Natural Phenomenon. Dennett's book argues that an evolutionary explanation for religious belief exists, and that religion can and should be examined empirically by science with the initial presumption of "methodological naturalism" (i.e. we must assume for the sake of argument that God does not exist in order to take on this investigation). Swinburne argues that no such investigation can be adequately undertaken without first determining whether the evidence supports belief in the existence of God and his activity in the world, especially with regard to the formation of religious belief. "Methodological naturalism," Swinburne claims, must first be justified by an argument showing that such a method leads to truth, and this will only be the case if its naturalistic assumptions are, in fact, correct.