Dr Sławomir Piekarczyk, PhD in the field of Law. He defended his doctoral dissertation on the Faculty of Law and Administration in University of Silesia in Katowice. Associated with the Institute of Legal Sciences — Theory and Philosophy of Law of this University. Didactician. Author of dozen research works, two of them received first awards. The scientific interests of the author are concentrating in particular around the theory and philosophy of law (including especially the issues concerning the vagueness of legal language, the methodological naturalism and the interpretation of texts of normative acts), as well as of issues of fields associated with the labor law, system of the Polish notary's office and — beside of law — humanities so as the philosophy and the social psychology.