  The ‘more’ here is Kant’s distinctive approach to metaphysics and epistemology; his Transcendental Idealism.  Hume had argued that since knowledge is based on experience, our knowledge of the world could not go beyond registering and mining regularities in that experience. The prospect of what Kant called synthetic a priori knowledge – of an understanding of the necessary structuring principles of reality – was beyond us.  Kant takes it as a given that we have such knowledge and sets out to construct a system that explains how such knowledge is possible.  His response to Hume’s challenge is to argue that the distinctive structure of experience is a function of our nature.  We impose regularities. If these regularities are recognized as our contribution, and we understand the structuring principles that are at work, we can make sense of the actuality of synthetic apriori knowledge. But the price we pay is that this is knowledge of the world of appearances, not about things as they are in themselves.