Inductive inference

According to a long tradition, an inductive inference is an inference from a premise of the form ‘all observed A are B’ to a conclusion of the form ‘all A are B‘. Such inferences are not deductively valid, that is, even if the premise is true it is possible that the conclusion is false, since unobserved As may differ from observed ones. Nevertheless, it has been held that the premise can make it reasonable to believe the conclusion, even though it does not guarantee that the conclusion is true.

It is now generally allowed that there are many other patterns of inference that can also provide reasonable grounds for believing their conclusions, even though their premises do not guarantee the truth of their conclusions. In current usage, it is common to call all such inferences inductive. It has been widely thought that all knowledge of matters of fact that we have not observed must be based on inductive inferences from what we have observed. In particular, all knowledge of the future is, on this view, based on induction.