This paper dwells upon formal models of changes of beliefs, or theories, which are expressed in languages containing a binary conditional connective. After defining the basic concept of a (non-trivial) belief revision model. I present a simple proof of Gärdenfors''s (1986) triviality theorem. I claim that on a proper understanding of this theorem we must give up the thesis that consistent revisions (additions) are to be equated with logical expansions. If negated or might conditionals are interpreted on the basis of (...) autoepistemic omniscience, or if autoepistemic modalities (Moore) are admitted, even more severe triviality results ensue. It is argued that additions cannot be philosophically construed as parasitic (Levi) on expansions. In conclusion I outline somed logical consequences of the fact that we must not expect monotonic revisions in languages including conditionals. (shrink)

The paper proposes a unified analysis of the natural language connectives 'if', 'if … might', 'even if' (all of them with indicative and subjunctive mood), 'because' and 'though'. They are all interpreted as instances of universal (pro)conditionals, unconditionals, or counterconditionals. The paper imports the notion of relevance into the meaning of conditionals, viewing conditionals as close in meaning to explanations and statements about causal relations. The antecedent of a conditional is interpreted as being relevant for its consequent, thus avoiding the (...) general inference from A and B to 'If A, B'. The analysis is based on different variants of the Ramsey test (among them the 'Strong Ramsey Test') together with a fragment of the belief revision theory of Alchourrón, Gärdenfors and Makinson. (shrink)