Here is my resume in English (as of sept 2008) or a short version in French there.
Comittee: Johan van Benthem, Jacques Dubucs, Gerhard Heinzmann, Gabriel Sandu, Gila Sher, Dag Westerståhl.
Preliminary reports: Solomon Feferman, Gerhard Heinzmann.
Defended on novembre 16, 2006, summa cum laude
The problem of the characterization of the class of logical constants is one of the major issues in the philosophy of logic. The definition of the notion of logical consequence, in particular, depends on the delimitation of the boundary between logical and non-logical expressions. On the standard semantic approach to this problem, logical operations are characterized as operations which are invariant under permutation. The aim of this work is to assess the conceptual grounds of this thesis and the objections which have been raised in the literature. On the basis of a revision of the justifications of the thesis, we defend an alternative characterization of logical constants in terms of invariance under potential isomorphism. This new thesis is meant to account for the generality of logic and its lack of empirical and, in some sense to be made precise, of mathematical content.