In this article the author tries to give an answer - from the point of view of the transcendental pragmatic foundation of discourse ethics - to the title question, which was raised by the Unesco conferences entitled `Universal Ethics' in Paris (27 March 1997) and Naples (December 1997). The article should be understood as a supplement to the empiristic-comparative responses of S. Bok and H. Küng, and especially to the communitarian approach of M. Walzer, proposed at the first conference. Unlike (...) traditional rationalism, this approach does not try to deduce concrete moral norms from axiomatic first principles; it begins with transcendental reflection on the undeniable moral presuppositions of argumentative discourse (which is not circumventable in philosophy). The approach first deduces from these presuppositions only the ideal procedures for the moral discourses through which all concrete moral problems ought to be solved, if possible. The second step provides a strategic-counter-strategic supplementation principle for those cases where undistorted moral discourses are not possible. (shrink)