Any philosophy proceeds from a central intuition or seeing in the light of which it describes, explains and evaluates everything else. The prima intelligibilia of the medieval philosophers, the Cogito of Descartes, the Transcendental Subject of the German idealists are examples of such a "primitive fact" or "originary intuition" or "central reference point." This primitive fact, as Albert Dondeyne points out, is not necessarily a conceptual evidence or an idea capable of being developed into a universal system by means of an a priori deductive process. It is more often an "existential" experience, a certain manner of living and of grasping our life on the basis of a particular sensitivity towards some general aspect of things or towards some fundamental value, in consequence of which the whole of reality is viewed in a certain way. This all-embracing or comprehensive source of meaning confers a certain intelligible clarity on all things and permits us to situate them, each in its place, in the world and in our experience. It is thus not only a center from which we see the real, but also a point of departure from which we comprehend the real.