As pointed out by Stephen Jay Gould in his first published paper (Gould, 1965), uniformitarianism conflates two different classes of concepts. One, which Gould designated as ‘‘substantive,’’ makes ontological claims about the world, in that presumptions are made about how nature actually is, e.g., its processes change relatively slowly and are uniform over time and space. The other class of claims is methodological, in that injunctions or sugges- tions are made, based on present-day observations, to apply that present-day process understanding to conditions in the past (or future). In their recent paper Knight and Harrison (2014) observe that substantive uniformitarianism, which they define as ‘‘the Principle of Uniformitarianism’’ or as ‘‘the ‘strong’ principle or doctrine developed by Hutton and later by Lyell’’ (Camandi, 1999), has been largely discredited by Gould (1965) and others. They note that the many previous criticisms of uniformitarianism have focused on the research approach rather than on the research object. They define the latter as ‘‘Earth’s physical systems,’’ and they claim that this, ‘‘. . .cannot be meaningfully investigated using a uniformitarian approach. . .’’