Being and duty : the contribution of 20th-century Polish thinkers to the theory of imperatives and norms / Jacek Jadacki ; editing team, Piotr Michal Godlewski, Aeddan Shaw ; cover design, Mariusz Banachowicz ; layout, Miroslaw Krzyszkowski ; typesetting, Wydawnictwo Profil-Archeo, Magdalena Dziegielewska.