After an Introduction, Section One of the Philosophy of Nature, Mechanics, expands on this progression through considerations of space and time, matter considered as the diversity of individual bodies distributed in space and time, and finally the idea of universal gravitation as the determinate concept of such corporeal matter realized as idea (PN: §270). In the Newtonian laws of mechanics, however, the unity of matter is still only formal, and in Section Two, Physics, the determinateness of form is now considered as immanent within such corporeal matter.