Luxemburger Zirkel

The Luxemburger Zirkel is a group of researchers with a common interest in philosophical logic and philosophy of mathematics. In particular, we are interested in the theory of truth and other modal notions. We are also working on a project about Carnap's Logischer Aufbau and a project about structuralism in philosophy of mathematics.

Our group is sponsored by the British Academy under the title Logical Methods in Epistemology, Semantics, and Philosophy of Mathematics.

Core Members
from left: Leon Horsten, Leuven/Bristol Philip Welch, Bristol, project leader Hannes Leitgeb, Bristol Volker Halbach, Oxford
Meetings Weihnachtskolloquium Göttingen 20. December 2002 Salzburg 13.-15. May 2003 Bristol 6.-8. January 2005 New College, 4. June 2005 New College 25.-26. September 2006 Day of Truth 6. June 2008, Bristol Mathematical Methods in Philosophy 19.-21. September 2008, Bristol

Joint Papers

So far the members have written the following joint papers:

• Volker Halbach and Leon Horsten: “Two proof-theoretic remarks on EA+ECT” Mathematical Logic Quarterly 46 (2000), 461-466.
• Leon Horsten and Hannes Leitgeb: “No future” Journal of Philosophical Logic 30 (2001), 259-265.
• Volker Halbach and Leon Horsten: “Recent Developments in the Theory of Truth” in Principles of Truth, Volker Halbach & Leon Horsten, Hänsel-Hohenhausen, Frankfurt a.M., 2002, 11–35.
• Volker Halbach, Hannes Leitgeb and Philip Welch: “Possible Worlds Semantics for Modal Notions Conceived as Predicates” Journal of Philosophical Logic 32 (2003), 179-223.
• Volker Halbach and Leon Horsten: “Computational Structuralism”, Philosophia Mathematica 13 (2005) pp.174-186.
• Volker Halbach and Leon Horsten: “The Deflationist's Axioms for Truth” in Deflationism and Paradox, JC Beall and Brad Armour-Garb (eds.), Oxford University Press, 2005, 203-217.
• Volker Halbach, Hannes Leitgeb and Philip Welch: “Possible Worlds Semantics for Predicates” in Intensionality, Reinhard Kahle (ed.), Lecture Notes in Logic 22, Association of Symbolic Logic, A K Peters, Wellesley, 2005, 20-41.
• Volker Halbach and Leon Horsten: “Axiomatizing Kripke's Theory of Truth”, Journal of Symbolic Logic 71 (2006), 677-712
• Leon Horsten and Philip Welch: “The undecidability of propositional adaptive logic”, preprint, 2005.
• Volker Halbach and Philip Welch: “Necessities and Necessary Truths: A Prolegomenon to the Metaphysics of Modality”, Mind 118 (2009), 71-100
• Hannes Leitgeb und Leon Horsten: “How Abstraction Works”, to appear in: A. Hieke and H. Leitgeb (eds.), Reduction and Elimination in Philosophy and the Sciences, Ontos Press.

Some papers or their abstracts are available from the websites of Philip Welch and Volker Halbach.

last change: 19 July, 2009

e-mail address (please replace "0" by the usual "@" symbol): volker.halbach at philosophy.oxford.ac.uk