The relation of mind and body is one of the central problems of post- Cartesian times. It has precluded a unified theory of the positive sciences and prevented a satisfactory notion of man's psychophysical unity. Gen- erally it has been treated as a problem of causality and solutions have been sought in various schemata of etiological relations. Proposals have ranged from that of reciprocal action between two substances and two causal streams to a reduction of all phenomena to a single causal stream involving a single class of substances. This investigatiDn will abandDn such schemata and attempt to' start afresh. It will analyze the relation Df strata Df meaning invDlved and will be Dnly tangentially concerned with the causal relatiDns Df mind and body. This investigation will view the relation Df mind and body no lDnger as the associatiDn Df twO' substances, twO' things, but as the integratiDn Df two levels of conceptual richness. This is a move from hypostatization, reification, to' categorializatiO'n - a mDve from the O'pacity Df things to' the relative lucidity Df their significance.
It recognizes that philO'SOphy seeks not new facts about being but rather a way Df understanding the integratiDn Df widely diverse domains Df facts. Here the gDal is the expla- natiDn of the unity Df being, specifically the being of mind and bDdy, in terms Df thDught - that fDr which being has significance and that for which incongruities of significance appear as a problem.