Ius naturale or natural law came to be defined as a byword for an indefinite number of higher laws upon which the validity of positive law stands. Though for convenience's sake this definition may suffice, it is, in our opinion, far better to speak of several and distinct theories of natural law legal- and political philosophies, all sharing some common features and defining peculiarities alike. All of these theories have some history, worthy of succinct examination, but besides its historical curiosity natural law legal philosophy does, in fact, have something to do with contemporary law and politics as well. Ius Naturale Research Group was established on these two pillars of natural law: on the one hand, it conducts researches into the history of natural law theories, and on the other hand, its researchers endeavour to apply the principles of natural law legal philosophy to contemporary discussions over fundamental human rights, euthanasia, marriage and family, bioethics, etc.