# Kai Wehmeier

Kai Frederick Wehmeier (born 1968) is a German-American philosopher and logician.

Kai Wehmeier
Born15 March 1968
NationalityUnited States, Germany
Alma materUniversity of California, Berkeley (M.A.); Ruhr-Universität Bochum, Germany (M.A.); Westfälische Wilhelms-Universität Münster, Germany (Ph.D.)
Scientific career
FieldsLogic, Philosophy of logic, Philosophy of language, Philosophy of mathematics, Metaphysics, Early Analytic Philosophy (especially Frege and Wittgenstein)
InstitutionsUniversity of California, Irvine
ThesisSemantical Investigations in Intuitionistic First-order Arithmetic[1] (1996)
Doctoral advisorJustus Diller, Wolfram Pohlers

He is best known for proving that the fragment of Frege's inconsistent logical theory of Grundgesetze der Arithmetik becomes consistent upon restricting the complexity of comprehension formulas in the second-order comprehension schema to ${\displaystyle \Delta _{1}^{1}}$, for his development of a system of subjunctive modal logic and its use in rebutting Kripke's modal argument against description theories of proper names, as well as for refining and defending the thesis that there is no binary identity relation between objects.

Wehmeier is currently a professor in the Department of Logic and Philosophy of Science and the Department of Philosophy at the University of California, Irvine. He is also the director of UC Irvine's Center for the Advancement of Logic, its Philosophy, History, and Applications (C-ALPHA).[2]