As indicated by the above characterization of the mid-twentieth-century American movement, naturalism can be separated into an ontological and a methodological component. The ontological component is concerned with the contents of reality, asserting that reality has no place for “supernatural” or other “spooky” kinds of entity. By contrast, the methodological component is concerned with ways of investigating reality, and claims some kind of general authority for the scientific method. Correspondingly, this entry will have two main sections, the first devoted to ontological naturalism, the second to methodological naturalism.