Problem of induction

1. generalizing about the properties of an entire class of objects based on a number of observations of particular instances of that class of objects (for example, all ravens are black birds); or
2. presupposing that the sequence of events in the future will occur as they always have in the past under the same conditions everywhere (for example, the law of gravitation is universal).

David Hume first addressed this problem in the 18th century and it has been an unresolved problem to empiricism ever since.

Nelson Goodman[?] presented a more sophisticated description of the problem of induction in 1966:

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