Isaac Levi on Abduction

Abstract

Progress is impossible without change; and those who cannot change their minds cannot change anything. George Bernard Shaw The purpose of this chapter is to survey Isaac Levi's conception of abduction and to contrast it with other work on abduction to be found in the literature. In particular, I concentrate on developments in abductive logics within the area of artificial intelligence where the main concern is to implement an abductive form of inference. I contrast the views to be found there with Levi's conception of abduction. In large part, I show that Levi's notion of abduction is quite distinct to what is found in the artificial intelligence literature. Deduction, induction, and abduction have variously been viewed as essential elements in the stages of scientific inquiry. Isaac Levi's work has gone a long way toward clarifying these notions and identifying their roles in a reasoner's process of inquiry. In brief, abduction is used to identify potential answers to an inquiry; induction selects the most desirable of these given the reasoner's requirements; and deduction determines the consequences of this selection. I seek to examine abduction's role in further detail by looking at Levi's notion of this process and contrasting it against other views. While I have less to say about induction and deduction, I also touch on them as the three processes form a coherent whole in Levi's work. I begin in the next section with a brief overview of Peirce's theory of abduction.