 Moreover, there are two connected, important further differences between Hume’s and Newton’s rules. First, Hume never quite endorses the universal reach implied by Newton’s third rule. For Newton we extend the known qualities of bodies within our experimental reach to all bodies in the universe. While it could be compatible with Newton’s third rule, Hume’s fourth rule does not go that far. There is one instance where Hume appears to accept an implication of Newton’s rule: “The production of motion by impulse and gravity is an universal law, which has hitherto admitted of no exception” (EHU 6.4). Leaving aside the fact that this would a very puzzling way to express the inverse-square law, the context makes clear that Hume has in mind causes that “are entirely uniform and constant” on Earth, not their universal reach; this is why in context his other examples involve the burning of fire and the suffocation of every human creature by water. There is textual support to suspect that Hume would deny the universal scope implied by Newton’s third rule. Hume states a “maxim” in a footnote to section XI of EHU which argues against inferring new effects from any cause only “known only by its particular effects”. This denies Newton’s strategy of making ever more audacious inferences (about planetary motions, the tides, the shape of the Earth, comets, etc) based on the acceptance of universal gravity (recall Hume’s treatment of Newton’s methodology in HE, VI, 542, discussed in  section 3).[8]  The argument in favor of the “maxim” reveals the tension with Newton’s third rule: