 It is rarely so. Therefore, inquiry into moral matters is just as open-ended as inquiry into natural matters, and the cure is the same here as there, pretty much as Newton envisaged: it is in further enquiry (Smith 2002: 160–161). So, for Hume experimental findings can and need to be further refined by methods that rightly belong to the family of Newtonian successive approximations: by exploring exceptions and limitations, or by eliminating superfluous conditions in order to identify the efficacious one (Demeter 2019b). One could see this feature of Hume’s method as anticipating Mill’s method of difference as much as resembling Newton of Opticks (see  Section 3.3 of the entry on John Stuart Mill).