 However, it has long been recognized that inductive inferences/arguments are not unproblematic. Hume famously offered the first influential formulation of what became known as “the problem of induction” in his Treatise of Human Nature (see entries on  David Hume  and on  the problem of induction;  Howson 2000). Hume raises the question of what grounds the correctness of inductive inferences/arguments, and posits that there must be an argument establishing the validity of the Uniformity Principle for inductive inferences to be truly justified. He goes on to argue that this argument cannot be deductive, as it is not inconceivable that the course of nature may change. But it cannot be probable either, as probable arguments already presuppose the validity of the Uniformity Principle; circularity would ensue. Since these are the only two options, he concludes that the Uniformity Principle cannot be established by rational argument, and hence that induction cannot be justified.