Critique of pure reason — Excerpt 1

Certain cognitions even abandon the field of all possible experiences, and seem to expand the domain of our judgments beyond all bounds of experience through concepts to which no corresponding object at all can be given in experience.
And precisely in these latter cognitions, which go beyond the world of the senses, where experience can give neither guidance nor correction, lie the investigations of our reason that we hold to be far more preeminent in their importance and sublime in their final aim than everything that the understanding can learn in the field of appearances, in which we would rather venture everything, even at the risk of erring, than give up such important investigations because of any sort of reservation or from contempt and indifference.