What About the Three Forms of Inference?

Abstract

Deduction, abduction, and induction are analysed. They are shown to consist in the connections between three terms: distinctive marks, equivalence classes, and properties. The general way in which these connections are established is through law-like hypotheses, sampling, and expectation. Moreover, each inference is shown to consist in a different form of expectation. Some of the ensuing consequences are shown, in particular those concerning fictional and abstract entities, class hierarchy, and extensional versus intensional logic.