TheCritique of Pure Reasonincludes an a priori foundation of the physical science, grounding on the fact that the universal shape of our Intellect gives its law to Nature. But not all features of the experienced world are submitted to such a "legislation": just what belongs to a nature "generally speaking"(Natur überhaupt).On the contrary, the specific aspects of the nature we live in should be extracted from experience as such: from an empirical research on facts. Now, what is extractedfromexperience, according to Hume's principle, which also for Kant is beyond question, doesn't possess any sort of intrinsic necessity. That is the reason why in the first Critique, and even more in theCritique of Judgmentoccur locutions such as "empirical laws' or "empirical concepts", which according to Criticism should be considered a mereoxymoron.