science, notwithstanding the object of his science, related only to the species, unconnected with individuals. What then remains to be proved, is, that in physics there is to be found no sort of science, or evident knowledge of the matters appertaining merely to physics, abstracted from all other considerations; and truly the dogmatic naturalists, would be very happy, could they be permitted to possess a knowledge that amounts to as much as this; nor would it disturb them, to have it dinned in their ears, that the knowledge of common conceptions is metaphysical, and not physical; for they would tell you, that both physics, and metaphysics, may depart or be separated from their singularity, and that the principal distinction between them is, that the last regards its object with a greater degree of abstraction; that is, as exempt from all matter, and considers only those reasons, which may subsist abstracted from matter, such for example as spiritual entities; on the contrary, physics only contemplate material and corporeal entities; the most sublime of which conceptions, is that which regards the reason of the body, and the lowest, that which is attached to the corporeal part of it. But call this knowledge by what sort of name you will, either physical or metaphysical, the way to bring the matter to a short issue is, to shew that there is not in reality, any such knowledge. XXXV. And what is more easy to be proved than this? I reason thus; physics contemplate the nature of an entity that has motion, or circulation; this may be considered, either according to the specific, or generative nature of the thing; and I assert, that nothing is known with certainty of the nature of any entity that has motion or circulation, either in one or the other of the before named senses.