Neutral Monism

Bertrand Russell set out neutral monism most carefully in works from the 1920s, arguing that what we call a physical object and what we call a perception of it are actually built from the same raw material, momentary sensory events he called sensibilia, organized one way when considered as part of a causal physical order and another way when considered as part of a perceiving mind's biography. On this view, asking whether a given sensory event is really mental or really physical is a bit like asking whether a given point in space is really horizontal or really vertical, a question that only makes sense once a frame of reference has been chosen, not a question with an answer built into the point itself.

William James's radical empiricism anticipated the same move: for James, pure experience is prior to the mind-matter distinction, and both terms of that distinction are later, useful ways of sorting one and the same primal stuff. The position's chief technical burden is explaining, in detail, how organizing neutral elements one way yields a full physical causal order and organizing them another way yields a subject with a genuine point of view, a burden critics argue neutral monists have never fully discharged, leaving the position more a promissory note than a worked out theory.

Neutral monism has never attracted the following that materialism or idealism has, in either philosophy or religion, in part because it is harder to build a devotional or ethical life around a stuff defined mainly by what it is not, neither mind nor matter, than around a clearly personal God or a clearly physical cosmos. Its closest religious analogue may be some readings of Taoism's undifferentiated Tao, prior to and generative of the paired opposites yin and yang, though Taoist sources describe that source in terms far removed from Russell's technical sensibilia and the comparison should be treated as a structural echo rather than a claimed influence.

Within philosophy the position is now most often discussed as an ancestor of contemporary panpsychism and Russellian monism, revived by philosophers trying to solve the hard problem of consciousness by positing that the intrinsic nature of physical stuff, hidden from physics itself, is exactly the neutral or proto-mental ground Russell and James were reaching for. The position's obscurity relative to its two more famous rivals is itself instructive: most people, and most religious traditions, find it far easier to commit to matter being basic or mind being basic than to commit to a third, less intuitive category defined mainly by what it refuses to be, which may explain why neutral monism has always been a minority position argued by specialists rather than a live option for ordinary religious or philosophical life.