 I will attempt to provide an explanation of the origin of the world system according to the general laws of mechanics, not an explanation of the entire natural order, but only of the great masses of matter and their orbits, which constitute the most crudest foundation of nature … I will presuppose the universal gravitation of matter according to Newton or his followers in this project. If there are any who believe that through a definition of metaphysics formulated according to their own taste they can annihilate the conclusions established by men of perspicacity on the basis of observation and by means of mathematical inference—if there are such persons, they can skip the following propositions as something which has only a remote bearing on the main aim of this essay. (Kant 1763: AK 2: 139)