In order to remain silent Da-sein must have something to say. - Martin Heidegger

Kant speaks of the "thing-in-itself" (Ding an sich) in order to distinguish it from the "thing-for-us" (Ding fur uns), that is, as a "phenomenon." A thing-in-itself is that which is not approachable through experience as are the rocks, plants, and animals. Every thing-for-us is as a thing and also a thing-in-itself, which means that it is recognized absolutely withing the absolute knowledge of God. But not every thing-in-itself is also a thing-for-us: God, for instance, is a thing-in-itself, as Kant uses the word, according to the meaning of Christian theology. p. 5

Kant's philosophy shifts for the first time the whole of modern thought and being (Desein) into the clarity and transparency of the foundation (Begrundung). This determines every attitude toward knowledge since then, as well as the bounds (Abgrenzungen) and appraisals of the sciences in the nineteenth century up to the present time. Therein Kant towers so far above all who precede and follow that even those who reject him or go beyond him still remain entirely dependent upon him. p. 55-56

Nevertheless, the ultimate business of philosophy is to preserve the force of the most elemental words in which Dasein expresses itself, and to keep the common understanding from levelling them off to that unintelligibility which functions in turn as a source of pseudo-problems.