According to J. Maréchal’s approach to metaphysics, spontaneous human knowledge is understood as the result of integrating the manifold contents of experience under the dynamism of the intellect. The aim of metaphysics is seen as making explicit the necessary differentiations in this process of an integrating synthesis. This leads to an operational understanding of key-terms and insights of classical metaphysics. Also, a life-carrying belief-system (Weltanschauung) aims at integrating the totality of human concerns. So metaphysics can be of help in a process of deepening critically these beliefs by showing minimal conditions for its consistency. It also contributes to understand the special rationality of a personal Weltanschauung, which was prepared by the discussion in Analytic Philosophy about religious language. So there can be shown both, the possibility and the limits of philosophical arguments in a dialogue concerning questions of ultimate personal concern.