Wolfgang Schwarz: Papers

Variations on a Montagovian Theme Draft (2011): What are the objects of knowledge, belief, probability, apriority or analyticity? For at least some of these properties, it seems plausible that the objects are sentences, or sentence-like propositions. However, various results from mathematical logic indicate that sentential properties are subject to severe formal limitations. After surveying these results, I argue that they are more problematic than often assumed, that they can be avoided by taking the objects of the relevant property to be coarse-grained ("sets of worlds") propositions, and that all this has little to do with the choice between operators and predicates.
Changing Minds in a Changing World Forthcoming in Philosophical Studies: I defend a general rule for updating beliefs that takes into account both the impact of new evidence and changes in the subject's location. The rule combines standard conditioning with a "shifting" operation that moves the center of each doxastic possibility forward to the next point where information arrives. I show that well-known arguments for conditioning lead to this combination when centered information is taken into account. I also discuss how my proposal relates to other recent proposals, what results it delivers for puzzles like the Sleeping Beauty problem, and whether there are diachronic constraints on rational belief at all.
Belief Dynamics across Fission Draft (2011): When an agent undergoes fission, how should the beliefs of the fission products be related to the pre-fission beliefs? This question has recently drawn some attention in the context of Everettian quantum mechanics, but it is of independent philosophical interest. Among other things, it provides counterexamples to popular principles concerning self-locating indifference, peer disagreement, and the relationship between objective chance and rational credence. It also supports the Lewisian “halfer” solution to the Sleeping Beauty problem, and illustrates the important difference between evidential probability and rational belief. Finally, this paper completes the general model of belief update presented in [Schwarz 2011], which did not apply to cases of fission.
Counterpart Theory and the Paradox of Occasional Identity Draft (2011): Counterpart theory is often advertised by its track record at solving metaphysical puzzles. Much of this puzzle-solving power, however, can be mimicked by alternative views. Here I focus on the paradox of occasional identity, also known as the paradox of fission and fusion, or the paradox of contingent identity. To spell out the counterpart-theoretic solution, Lewis's interpretation rules have to be extended beyond the language of quantified modal logic. I present a more comprehensive semantics that takes into account the multiplicity and sortal-dependence of counterpart relations, allows talking about specific times and worlds, and does not require names to denote present (or actual) individuals. I also explain why this semantics does not commit us to the more controversial metaphysical and semantic aspects of counterpart theory.
How Things are Elsewhere: Adventures in Counterpart Semantics Forthcoming in G. Russell and G. Restall (Eds.), New Waves in Philosophical Logic: I present a simple model theory for quantified modal logics based on ideas from counterpart theory, and argue that these models are superiour to Kripke models in a number of respects. I also extend the model theory to quantified hybrid logics, and compare it to interpretations employing "individual concepts".
Generalising Kripke Semantics for Quantified Modal Logics Draft (2011): This is a more technical companion to the previous paper. I define two kinds of counterpart models, using either a "positive" or a "negative" interpretation of terms for non-actual individuals. I prove that a pleasantly weak combination of positive free logic and the minimal modal logic K is sound and complete with respect to the class of positive models, and that a corresponding combination of negative free logic with K, with two further axioms, is sound and complete with respect for negative models. I also discuss at some length the complications that arise for substitution principles in counterpart models, and prove some results for systems that contain an explicit substitution operator in the object language.

Modal Metaphysics and Conceptual Metaphysics In H. Bohse et al. (Eds.), Selected Papers Contributed to the Sections of GAP.6, Sixth International Congress of the German Society for Analytical Philosophy, mentis: Paderborn 2007, pp.520--528: I compare the old-fashioned view of metaphysics as an inquiry into broadly conceptual connections with the by now equally old-fashioned view of metaphysics as an inquiry into modal connections. I argue against proposals by Jackson and Lewis that the two projects ultimately coincide, and claim that we should prefer the conceptual project.

Wolfgang Schwarz: Papers & Drafts