THE book is not a treatise on aIl cerebral mechanisms but a pro poscd solution of a specific problem: the origin of the nervous system's unique ability to produce adaptive behaviour. The work has as basis the fact that the nervous system behaves adap tively and the hypothesis that it is essentiaIly mechanistic; it proceeds on the assumption that these two data are not irrecon cilable. It attempts to deduce from the observed facts what sort of a mechanism it must be that behaves so differently from any machinc made so far. Other proposed solutions have usuaIly left open the question whether so...