The first part of this essay discusses what naturalism in the philosophy of religion should entail for one's ontology, considers various proposed criteria for categorizing something as natural, uses an analysis of these proposed criteria to develop theoretical criteria for both the natural and nonnatural, and develops a set of criteria for identifying a potentially supernatural event in practice. The second part of the essay presents a persuasive empirical case for naturalism based on the lack of uncontroversial evidence for any (...) potential instances of supernatural causation, with particular emphasis on the lack of evidence for supernatural causation in our modern scientific account of the history of the universe and in modern parapsychological research. (shrink)