  More precisely, Leibniz argues that God created the world so perfectly that each substance acts according to its own law of unfolding and is at the same time in perfect harmony with all others substances; further, that the mind has a distinct point of view of the world by virtue of its being the center of some mass (body), and that the law of unfolding of the mind is in accord with the laws of the corporeal machine. He puts this most succinctly in his 1695 essay, A New System of Nature, in which he effectively presents a five-step argument for pre-established harmony: