Changes

1) "I have found that such an object has always been attended with such an effect..."

2) "I foresee, that other objects, which are in appearance, similar, will be attended with similar effects." [[CiteRef:: Hume (1975) |p. 114]]

Newton supposed that the use of such inductive arguments could be justified by an appeal to the uniformity of nature. [[CiteRef::De Pierris (2006)]] Hume however, found a fundamental problem in rationally justifying inductive arguments. Consider the following argument, which might seem to justify our reliance on induction:

But this argument itself relies on induction, the very mode of argument it seeks to justify. As Hume put it: "According to my account, all arguments about existence are based on the relation of cause and effect; our knowledge of that relation is derived entirely from experience; and in drawing conclusions from experience we assume that the future will be like the past. So if we try to prove this assumption by probable arguments, i.e. arguments regarding existence, we shall obviously be going in a circle, taking for granted the very point that is in question." [[CiteRef::Hume (1748)| p. 16]] He concluded that "the conclusions we draw from experience are not based on reasoning or on any process of understanding". [[CiteRef:: Hume (1748) |p. 15]] But induction is necessary for the conclusions that we draw, not only in Newtonian science, but also in our daily lives, which would not be possible without it. Hume concludes that we are compelled to use induction by a powerful natural instinct, or more specifically his principles of association. "All these operations" he wrote, "are species of natural instincts, which no reasoning… is able either to produce or prevent". [[CiteRef::Hume (1975)| p. 46-47]] Humans must, Hume concludes, rely on "the ordinary wisdom of nature", which insures that we form beliefs "by some instinct or mechanical tendency", rather than trusting "the fallacious deductions of our reason". [[CiteRef::Hume (1975) |p. 55]] In keeping with this naturalistic conclusion, Hume devotes an entire section of the ''Enquiry'' to an argument that non-human animals also learn by induction. He writes that "it seems evident that animals, like men, learn many things from experience, and infer that the same outcomes will always follow the same causes". [[CiteRef::Hume (1748)| p. 53]] Hume’s conclusion was a radical challenge to the central role assigned by rationalists like Descartes and Leibniz to reason in the production of our knowledge, and is seen today as a step towards modern ideas in cognitive science and neuroscience.