DUALISM (Lat. dienii.c, relating to two). In philosophyg the theory that the universe is ex plicable only as a whole with two fundamentally different kinds of emistititent t•h•inents. The ancient dualism of matter and form has in mod ern been replayed by a diudism of mind and matter. \niong modern philosophers Des was the first to emphasize the radical difference between thinking s•Ilistanec (mind) and a ( mal ler). The difficulty suggested by this view was to eN141:1111 how Mind Ild matter interact a, they do in 1 caused some of his COn COM i t a MI' Of V a ri.i t inn ){.'t .% SION ; it (auscd others to d•n.% the truth (.1 dualisni alto gether (see NIoNtsw ; SPI NO% ; LEIGN117.). duce Deseart.s's day the question has been in con stant debate, :old eNen to-day there is no unanim ity aniong philosopher, as to the relative truth of dualism :end its rivals. 11 ithin recent years the interest awakened by seientitie psychology has brought the problem more to the fore, but exen in lisp:bolo:43 there is 110 on the subject. (See l'Art.u.i.m.ism.) Only a brief con structive criticism can be undertaken here. The sole source front \ditch a satisfactory solution can be obtained is experience. Doe, experience present us with one or two or even more ab solutely and inndann'nt.dly unrelated elements? In the first plaee, the contents of experienee, the various centrally and periphera Ily a roused. the a fleet ion, and Voljt ions, are, without quest ion, tlu:tlitaticely different. These may shade into each other I'oxrtxt ITY, LAW OF ), bat no recognition of this fact can negative the fart of difference. If monism denies the qualitative- dilferencr, it is of course false. Some monism doe this. Ifut other of monism are more subtle. admitting the existence of various differ ences, they assert that these differences are va rious manifestations Of a simple substance. Their views stand or fall with the conception of substance Ifni as the only tenable con ception of substance seems to lie that it is a synthetic unity of various quantities, it would ,..44.111 that while it is possible, and no doubt cor rect, to think of the universe as one 1.11/11WelVd system, or, in other Word-. a synthetic unit, it is just as necessary to thinly of the differences within the unity. If monism be defined as the doctrine of the fundamental oneness of things, it is compatible with pluralism if that is de fined as the doctrine of the fundamental plural ity of things; since in a synthetic unity neither the unity is more fundamental than the differ en•es, nor the than the unity. Fait is dualism compatible \VIII) monism and pluralism thus harmonized? Evidently it is. if pluralism
mean, that all the 11 in the universe can be reduced to two classes, the psychical and the physical, however these may be differentiated from each other. and if it asserts that the differ ences between these (-lasses cannot be obliter ated; for, as tenable monisin does not deny differences, lint asserts unity. Dualism is inconsistent with pluralism only if dualism denies the existence of more speeitie distinctions than those of psychical and physical. This dualism never does. Itualisin is inconsistent with monism Duly if it denies the possibility of 1-two...nixing the f„sy•llical and the physical as two aspects of one and the same experience. Dualism sometimes does this. and when it does it is false, for it overlooks the fact that the psychleal and tile physical fire distinctions found correlated within the unity of experience. Bud du•lism need not deny the correlation of physical and psychical within a synthetie unity, while yet insisting upon their irrediteible differ ences. Thus we find that monism, dualism, and pluralism are mutually compatible, if the fact is regarded that the maintenance of fundamental unity is compatible with that of fundament:0 duality of distinctions within that unity, and that fundamental duality of distinctions is com patible with fundamental multiplicity of more specitie The question as to the form in which the fundamental unity of the universe must be conceived is treated elsewhere.
:See tloNtsm.
But one further question remains to be dis c-us-oil here. In what way must the correlation of the physical and the psychical be conceived? Are they merely parallel distinction- within experience, or do they interact? This again de pends upon the meaning of terms. if by inter action is meant mechanical interaction or the transfer of energy in accordance with the law of the transformation of viler:iv (see F.NFRCETICS), then interaction is impossible unless it can be made out that psychical activity is a mode of spe cial motion (materialism). This cannot be done. All that can be made out empirically is that certain changes in the psychical are accent pitied and followed by certain changes in a cer tain portion of the physical phenomena, viz. the body, and vice versa. This may be expressed by saying that there is merely it parallelism. But if by interaction is meant that there is causal connection in the sense in which causality (q.v.) i- now used by the best modern logicians. there is interaction. That is. certain psychic events are invariably sequent upon certain physical events, and vice versa. See KNOWL