When I was setting forth this book of Observations upon Experimental Philosophy, a dispute chanced to arise between the rational parts of my mind concerning some chief points and principles in natural philosophy; for, some new thoughts endeavouring to oppose and call in question the truth of my former conceptions, caused a war in my mind: which in time grew to that height, that they were hardly able to compose the differences between themselves, but were in a manner necessitated to refer them to the arbitration of the impartial reader, desiring the assistance of his judgment to reconcile their controversies, and, if possible, to reduce them to a settled peace and agreement. The first difference did arise about the question, How it came, that matter was of several degrees, as animate and inanimate, sensitive and rational?