Hobbes's psychology is in the first place materialistic; he holds, that is, that in any of the psychophysical phenomena of human nature the reality is a material process of which the mental feeling is a mere " appearance."
The theory of psychophysical parallelism involves no doubt in the minds of the majority of its upholders the further assumption of some unity underlying both the physical and psychical series which may one day be discovered to be susceptible of scientific expression and interpretation.
But more convincing than most of the philosophical arguments by which the theories of psychophysical parallelism have been assailed is the fact that it runs counter to the plain evidence of the ordinary consciousness.
Accordingly, he calls these and all other processes " psychophysical "; and as he recognized two parallel energies, physical and psychical, differing only as outer and inner aspects of the same energy, he called this " psychophysical energy."
At the same time Fechner would not have us suppose that the two sides are equal; according to him, the psychical, being the psychophysical as viewed from within, is real, the physical, being the psychophysical viewed from without, is apparent; so in oneself, though nervous process and psychical process are the same, it is the psychical which is the reality of which the nervous is mere appearance; and so everywhere, spirit is the reality, body the appearance of spirit to spirit.