Contemporary philosophy is characterised by different methodological and content-related ontological oppositions. For example, analytical approaches esteeming natural sciences encounter hermeneutic and pragmatic projects, systems theories meet post-Marxist-inspired analysis of power and knowledge, and - time and again - discussions emerge between "discourse theory" and "deconstruction". Protagonists of the latter are Jacques Derrida and Jurgen Habermas. This book carefully conveys the contradiction between "discourse theory" and "deconstruction". It reconstructs their antagonism, exposes the origins of different theory formation, and undertakes fruitful comparisons that allow further findings. Thereby, it reveals essential problems of today's enlightenment and contemporary criticism of reason - and provides new insights into the "gigantomachy" between idealists and voluntarists, i.e. the basic dialectics moving the Western philosophy from the very beginning. A main focus is set on questions of law, right, and justice.