The book is dedicated to the theoretical problems concerningratiolegis. In the contexts of legal interpretation and legal reasoning, the two most important intellectual tools employed by lawyers,ratiolegis would seem to offer an extremely powerful argument. Declaring theratiolegis of a statute can lead to a u-turn argumentation throughout the lifespan of the statute itself in parliament, or in practice during court sessions, when it is tested against the constitution.

Though theratiolegis argument is widely used, much about it warrants further investigation. On the general philosophical map there are many overlapping areas that concern different approaches to human rationality and to the problems of practical reasoning. Particular problems withratiolegis arise in connection with different perspectives on legal philosophy and theory, especially in terms of the methods that lawyers use for legal interpretation and argumentation. These problems can be further subdivided into particular aspects of activities undertaken by lawyers and officials who use theratiolegis in their work, and the underlying theories. In short, this book examines whatratiolegis is, what it could be, and its practical implications.

Dr. iur. Verena Klappstein M.A., LL.M.isHabilitandin at University of Passau (Faculty of law, Professorship for German and European Private Law, Civil Procedural Law and Legal Theory ofProf. Dr. Thomas Riehm). The working title of herHabilitation based onKantian Moral Philosophy is: Vertragsfreiheit durch Kontrahierungszwang und -verbot (Freedom of Contract via obligation to and prohibition to contract). Her main research areas are Private, Company and Business Law, Legal Philosophy and Philosophy of Science.
Dr Maciej Dybowski is a lawyer and a philosopher, working as an assistant professor at the Chair of Theory and Philosophy of Law, Faculty of Law and Administration, Adam Mickiewicz University in Pozna, Poland. His main fields of research include philosophy of law, neopragmatism, law and language, philosophy of human rights.

Part I What IsRatio Legis?The Real Ratio Legis and Where to Find It - A Few Pragmatic Considerationsby Adam Dyrda.- Ratio Legis as a Binding Legal Valueby Marzena Kordela.-ArticulatingRatio Legis and Practical Reasoningby Maciej Dybowski.-Legislative History, Ratio Legis and the Concept of the Rational Legislatorby Micha Krotoszyski.-Part II What CanRatio Legis Be?The concept of purpose inKants Metaphysical Elements of Justiceby Verena Klappstein.-Nonconsequential Conception of Neutralityby Wojciech Ciszewski.-Is There a ImitativeRatio Legis and If So, How Many Are There? Psychological Perspectiveby Teresa Chirkowska-Smolak and Marek Smolak.-Part III What Practical Implications CanRatio Legis Have?Immanent Ratio Legis?  Legal Forms and Statutory Interpretationby Konstanze von Schütz.-How Can Ratio Legis Help a Lawyer to Interpret a Legal Text? Employing the Purpose of a Regulation for Legal Interpretationby Mikoaj Hermann.