An honest appraisal of historical geology must recognize that interpretations of earth history include elements other than scientific investigation. These interpretations are more properly evaluated by primary, formal tests for internal consistency between their extrascientific foundational principles (axioms) and conclusions. Failure of these formal tests automatically invalidates any system of interpretation, prior to empirical evidence. Success in passing formal tests does not guarantee success in field interpretation; it only provides the framework within which successful models of earth history may be constructed. The application of this method to the underlying naturalist-uniformitarian paradigm of modern historical geology shows it to be invalid because it fails tests of internal consistency when comparing its conclusions to its axioms in the following areas: the nature of the cosmos, of man, and of history. Thus, a valid model of geologic history cannot be generated within the naturalist-uniformitarian system.