Mary Claims to be Psychic

Mary is a fraud.

Although both in science and in daily life, we rely heavily on the methods of inductive reasoning, this kind of reasoning raises a number of perplexing problems. The most famous problem concerning the legitimacy of induction was formulated by the eighteenth-century philosopher David Hume, first in his Treatise of Human Nature and then later in his Enquiry Concerning Human Understanding. A simplified version of Hume’s skeptical argument goes as fol- lows: Our inductive generalizations seem to rest on the assumption that unob- served cases will follow the patterns that we discovered in observed cases. That is, our inductive generalizations seem to presuppose that nature operates uni- formly: The way things are observed to behave here and now are accurate indicators of how things behave anywhere and at any time. But by what right can we assume that nature is uniform? Because this claim itself asserts a con- tingent matter of fact, it could only be established by inductive reasoning. But because all inductive reasoning presupposes the principle that nature is uni- form, any inductive justification of this principle would seem to be circular. It seems, then, that we have no ultimate justification for our inductive reasoning at all. Is this a good argument or a bad one?