The Commens Dictionary
Quote from ‘Letters to Mario Calderoni’
… there are but three elementary kinds of reasoning. The first, which I call abduction (on the theory, the doubtful theory, I confess, that the meaning of the XXVth chapter of the second book of the Prior Analytics has been completely diverted from Aristotle’s meaning by a single wrong word having been inserted by Apellicon where the original word was illegible) consists in examining a mass of facts and in allowing these facts to suggest a theory. In this way we gain new ideas; but there is no force in the reasoning. [—] … induction is, as Aristotle says, the inference of the truth of the major premiss of a syllogism of which the minor premiss is made to be true and the conclusion is found to be true, while abduction is the inference of the truth of the minor premiss of a syllogism of which the major premiss is selected as known already to be true while the conclusion is found to be true. Abduction furnishes all our ideas concerning real things, beyond what are given in perception, but is mere conjecture, without probative force.