Verisimilitude and Belief Change for Conjunctive Theories

Two of the best known formal approaches are the post-Popperian theories of verisimilitude (for short: PPV) and the AGM theory of belief dynamics (for short: AGM).2 Our main purpose in this paper is the analysis of some conceptual (dis)similarities and relations between PPV and AGM. In the first two sections the emergence of the logic of scientific change in contemporary philosophy of science is shortly described and the basic features of the instrumental view of theory change are illustrated. While all the versions of PPV share the thesis according to which verisimilitude, or truth approximation, is the basic aim of science, this cognitive goal does not play any explicit role within the current versions of AGM. In spite of this, we will ask whether the methods for belief change proposed within AGM are an effective tool for truth approximation. After a brief presentation of the basic elements of PPV and AGM, it will be argued that a positive answer to the above question can be given.