 Yet Hume raises radical skeptical doubts about this very principle. It has no foundation in reasoning: neither in demonstrative reasoning nor (on pain of circularity) in inductive reasoning itself. Nevertheless, as firmly based in custom or habit, it is a universal principle of the human mind. Moreover, it is also the foundation for the best available science of matters of fact—Newtonian inductive science—and for Hume’s own inductive science (self-consciously following Newton) of human  nature.[23]  Thus, when Hume sets his radical skeptical doubts aside, the application of our foremost empirical scientific method (based on uniform constant conjunction) has normative force, and it thereby leads to the articulation of universal, exceptionless laws of nature which, as such, we are compelled to treat as necessary until experience teaches us otherwise (in accordance with Newton’s Rule 4 in Book 3 of the Principia: see  note 19  above).[24] It is because the idea of necessary connection, for Hume, arises from the application of the Newtonian inductive method that our projection of an inner feeling of determination onto nature does not merely reduce to a blind instinctual disposition, but amounts to a normative methodological standard in our best scientific understanding of  nature.[25]