Both, however, used this influence freely; and, whereas Lotze used the Leibnitzian argument from indivisibility to deduce indivisible elements and souls, Fechner used the Leibnitzian hypotheses of universal perception and parallelism of motions and perceptions, in the light of the .Schellingian identification of physical and psychical, to evolve a world-view (Weltansicht) containing something which was neither Leibnitz nor Schelling.
Fechner's second point was that, throughout the animated universe, physical processes accompany psychical processes without interaction.
Fechner's supposition was that the unity of consciousness belongs to the unity of the whole body; that the seat of the soul is the living body; that the soul changes its place as in different parts a process rises above the " threshold of consciousness "; and that soul is not substance but the single psychical life which has its physical manifestation in the single bodily life.
In 1860 appeared Fechner's Elemente der Psychophysik, a work which deeply affected subsequent psychology, and almost revolutionized metaphysics of body and soul, and of physical and psychical relations generally.
He now compared the spiritual and bodily sides of a man to the concave and convex sides of a circle, as inner and outer sides of the same process, which is psychical as viewed from within and physical as viewed from without.