A Professor of Philosophy and the chair of the Department of Logical Semiotics in the Institute of Philosophy at the University of Warsaw. Presently (from 2016) the dean of the Faculty of Philosophy and Sociology UW. In the years 2001-2015 editor-in-chief of the Filozofia Nauki (Philosophy of Science) quarterly. His main areas of interest are: (1) philosophy of language, specifically the problems of philosophical foundations of Categorial Grammar and the methodological aspects of the interface between philosophy and linguistics (incl. experimental philosophy); (2) theory of intentionality and metaphilosophy (analytic tradition); (3) theory of rationality and philosophy of religion. He is the author of three books, including Philosophy of Syntax (Springer, 2010) and many articles published in Philosophical Studies, Semiotica, Acta Semiotica Fennica, Studies in Logic, Grammar and Rhetoric, Polish Journal of Philosophy, Przegląd Filozoficzny, Zagadnienia Filozoficzne w Nauce or Studia Semiotyczne.