Hans Rott

This is a survey paper. Contents: 1 Introduction -- 2 The representation of belief -- 3 Kinds of belief change -- 4 Coherence constraints for belief revision -- 5 Different modes of belief change -- 6 Two strategies for characterizing rational changes of belief - 6.1 The postulates strategy - 6.2 The constructive strategy -- 7 An abstract view of the elements of belief change -- 8 Iterated changes of belief -- 9 Further developments - 9.1 Variants and extensions of belief revision - 9.2 Updates - 9.3 Default inferences as expectation revision - 9.4 Belief merging -- 10 Concluding remarks

According to Otto Neurath, the practice of science consists in a large undertaking of setting up and maintaining systems of statements: In unified science we try ... to create a consistent system of protocol statements and nonprotocol statements . When a new statement is presented to us we compare it with the system at our disposal and check whether the new statement is in contradiction with the system or not. If the new statement is in contradiction with the system, we can discard this statement as unusable , for example, the statement: ‘In Africa lions sing only in major chords’ ; however, one can also ‘accept’ the statement and change the system accordingly so that it remains consistent if this statement is added. The statement may then be called ‘true’

This collection includes twenty original philosophical essays in honour of Wolfgang Spohn. The contributions mirror the scope of Wolfgang Spohn’s work. They address topics from epistemology (e.g., the theory of ranking functions, belief revision, and the nature of knowledge and belief), philosophy of science (e.g., causation, induction, and laws of nature), the philosophy of language (e.g., the theory of meaning and the semantics of counterfactuals), and the philosophy of mind (e.g., intentionality and free will), as well as problems of ontology, logic, the theory of practical rationality, and meta-philosophy. ― Contributors: Ansgar Beckermann, Wolfgang Benkewitz, Bernd Buldt, Ralf Busse, Christoph Fehige, Wolfgang Freitag, Gordian Haas, Volker Halbach, Franz Huber, Andreas Kemmerling, Manfred Kupffer, Hannes Leitgeb, Godehard Link, Arthur Merin, Thomas Müller, Julian Nida-Rümelin, Martine Nida-Rümelin, Hans Rott, Holger Sturm, Thomas Ede Zimmermann, Alexandra Zinke.

Communication problems between members of different cultures may be due to "genuine" disagreement or "mere" misunderstanding. I argue that there is anthropological evidence that efficient communication across different cultures and languages is feasible, since (i) the degrees of sophistication in thinking or talking are not fundamentally different (the case of "Chinese counterfactuals") and (ii) the basic logics used are not fundamentally different (the case of "Zande logic"). Disagreements and misunderstandings are not clearly separable, however, because (iii) it is only relative to a given translational scheme that one can talk of a member of one culture denying what a member of another culture affirms. The latter claim is illustrated by a logical analysis of a made-up example.

Richard Bradley has initiated a new debate, with Brian Hill and Jake Chandler as further participants, about the implications of a number of so-called triviality results surrounding the Ramsey test for conditionals. I comment on this debate and argue that ‘Inclusion’ and ‘Preservation’, which were originally introduced as postulates for the rational revision of factual beliefs, have little to recommend them in the first place when extended to languages containing conditionals. I question the philosophical method of postulation that was applied in the new debate, and instead base my arguments on explicit representations of belief states and canonical constructions of belief state revisions.