The New International Encyclopædia/Mind-Stuff Theory

MIND-STUFF THEORY. A metaphysical theory which explains the relation of matter and mind by affirming their identity under the form of atoms of mind-stuff. These atoms are of a nature between physical atoms and psychical monads, representing an indivisible element, as the former, but being qualitatively rather than quantitatively determined, as the latter. Mind and matter, according to this theory, are but forms of composition of the atoms of mind-stuff; only under the most rarely favorable conditions does this composition result in intelligence, as in the higher animals, but at the same time no matter is to be conceived as ‘dead’ matter, since it is built up of elements whose essential character is psychical. The theory was propounded by W. K. Clifford, in Mind (old series), vol. iii.