THE ORIGIN AND SIGNIFICANCE OF CEREBRAL CORTEX 107 



In our search for the laws of growth and normal action of the 

 nervous S3^stem, we naturally and properly look, first, for those fea- 

 tures which can be fitted into the conventional formulations of in- 

 organic mechanics. Up to the present time the science of neurology 

 has been concerned almost exclusively with this aspect of the prob- 

 lem, with eminently successful results. Mechanical stress and ten- 

 sion, pressure and movements of fluids, local chemical action, surface 

 tensions and permeabilities, electrical phenomena of many kinds — 

 these and other physical factors now under investigation are bringing 

 to light many basic principles of nervous action. In a wider field 

 D'Arcy Thompson's great work. On Growth and Form ('44), does not 

 trespass beyond these boundaries, for he says (p. 15) : "When we use 

 physics to interpret and elucidate our biology, it is the old-fashioned 

 empirical physics which we endeavour, and are aloije able, to apply." 

 A useful general summary of Medical Physics, edited by Otto Glasser 

 ('44), has recently been published. But this line of attack sooner or 

 later reaches limits beyond which it has not yet been possible to go. 



In human neurology the major problem of all times has been the 

 relation of these physicochemical processes to the conscious experi- 

 ence which emerges from them. The normal subjective life is not dis- 

 orderly, but the laws of this order as revealed by introspective psy- 

 chology seem to be incommensurable and disparate with those of the 

 underlying physicochemical system as known objectively. This gap 

 has not been bridged by any acceptable formulation in terms of 

 Newtonian mechanics, and more and more of the experts in this field 

 are coming to believe that this cannot be done. This does not imply 

 any appeal to mysticism. Quantum mechanics takes its place in the 

 order of nature along with Newtonian mechanics, and it may well be 

 that the solipsistic qualities of that "private" conscious experience 

 which is not objectified are related to the events of the objectively 

 known "public" physicochemical world in accordance with prin- 

 ciples as different from those of Newtonian mechanics as the latter 

 are from quantum mechanics. If so, these principles of the mind-body 

 relationships have not yet been formulated, and we live in hope that 

 some day this will be done. Just as quantum mechanics has added a 

 time dimension to the three Cartesian co-ordinates of space and addi- 

 tional dimensions beyond our range of experience in theoretic mathe- 

 matical physics, so it may well be that introspective experience and 

 objective or extraspective experience are related in terms of dimen- 

 sions not yet recognized and given scientific expression, defining a 



