Abstract
From the perspective of Catholic moral theology, one of the most important topics in view of the tense relationship between law, ethics and religion is natural law. The first part of the present text tries to defend this type of theory, which goes back to antiquity, against the most important objections and to determine the contours of a contemporary form of natural law thinking. In the second part of the text, their practical importance is indicated using the example of the current debate about the moral evaluation of suicide and suicide assistance as well as dealing with the phenomenon of so-called transgenderness.