Idealism and panpsychism seem to me to make easy friends in the debate against materialism. They both affirm that consciousness or experience or mind in some generic sense are intrinsic to Nature. There are important differences between idealism and panpsychism, of course, and there are a variety of ways one can be an idealist or a panpsychist. More on that another time.
Materialism fails to account for the unity of consciousness (this is also a problem for the “constitutive” variety of panpsychism, the so-called “combination problem” that James is credited with recognizing in the “mind-dust” chapter of Principles of Psychology). This is problematic for materialism because physical science is premised on the unity of Nature: unless Nature forms a system, we can have no scientific knowledge of it, material or otherwise. Where does this unity come from, though? Certainly no material cause can account for it. Even the materialists admit that matter can only scatter; it cannot unify. The matter of the materialists has no purposes or ideals in mind, no holotropic archetypal movements, no emergent evolutions.
The materialist story goes like this: matter just mutely extends, it falls in the void. But at least on this planet, due to a strange swerving in the velocities of the void, or by some accident of natural selection, self-producing and reproducing membranes have arisen (a miracle!), followed by complex brains that learn from experience and, at least in one species, have developed into an immensely powerful symbolic consciousness that now dominates every life-system on the planet (a curse?).
If matter is all there is, there is no unity to Nature or to consciousness. Eliminative materialists try to retrieve unity/monism by arguing that there is just no such thing as consciousness, there is only the functioning of physical and biological algorithms: we are a language-generated “user-illusion” in Dennett’s terms. But most materialists remain reluctant dualists. They do not deny the reality of their own experiential existence, but they see no intrinsic relation between their inner experience and the material world projected outside them. They say Nature has absolutely nothing in common with human consciousness. Nature is utterly mindless and entirely blind, just a prison of colliding particles for all eternity. Human minds are a freak accident in an otherwise entropic universe, granted our few precious centuries of civilizational activity, we like every material thing are destined for chaos and destruction.
James is not at all dismissive of the materialist position. Large sections of his Principles of Psychology are devoted to brain anatomy and physiology. He insists that “the brain is the one immediate mental condition of the mental operations,” that “no mental modification ever occurs which is not accompanied by or followed by a bodily change.”
It would not be unfair, I think, to speculate that James’ well-known struggle with depression resulted from the seriousness with which he considered the materialistic doctrine. For a time, the doctrine robbed him of his will to live, of any sense of freedom or possibility in life. But he came to recognize the irreducibility of the feeling of freedom in himself, and thus of necessity was led to reject the materialist doctrine and to search for an alternative ontology of unity, not as in Nature or Mind exclusively, but in the continuous stream of “pure experience.”
James is not a systematic thinker; he assembles ideas and theories as needed to solve the problems that arise in the course of his thinking. But in each act of assembly he always recognizes the need for metaphysical coherence, that is for continuity of thought. Mind and body, whatever else they are, cannot be coherently conceived of as separate substances. Of this James is absolutely certain. While James acknowledges the diaphaneity of consciousness, unlike the eliminative materialists, he refuses to reduce mind to matter. Further, unlike the absolute idealists, he refuses to reduce matter to mind. He is neither a materialist nor an idealist. What is he left with? A sort of “neutral monism” as it came to be called once Bertrand Russell got a hold of it? I think there is something Russell missed, something untamed and wild in James’ “radical empiricism” that had to wait for Whitehead to give it wings. James recognized that consciousness is not a thing, it is a relational process. And he understood that all our scientific knowledge of matter in external Nature is itself of an experiential nature, of a kind with our inner sensations and imaginings. The type of experience called “physical” forms the core of our perceptual world, it is the group of experiences that forms our behavioral habits, that obeys Newton’s laws and accrues energetic consequences along its route through spacetime. It is nonetheless of the same experiential kind as that sort of experience that hovers on the fringes of our consciousness, where “laxly connected fancies and mere rhapsodical objects floats like a bank of clouds” (“Consciousness Exist?”, p. 489). Physical experience and mental experience are both modes of experience.
But James may not fully have dissolved the ontological boundary between thought and thing, subject and object, inner and outer… He may need Whitehead’s help here. Whitehead generalizes James’ psychology of “pure experience” into a cosmology of concrescing prehensions.