TRUTH 



that the brain, or psychic organ, in man behaves just 

 as it does in the other mammals, and especially the 

 primates. This paradoxical dualism of some of our 

 modern physiologists may be partly explained by the 

 perverse theory of knowledge which the great authority 

 of Kant, Hegel, etc., has imposed on them; and partly 

 by a concern for the current belief in immortality, and 

 the dread of being decried as "materialists" if they 

 abandon it. As I do not share this belief, I examine and 

 appreciate the physiological work of the phroneta just as 

 impartially as I deal with the organs of sense or the 

 muscles. I find that the one is just as much subject as 

 the other to the law of substance. Hence we must re- 

 gard the chemical processes in the ganglionic cells of the 

 cortex as the real factors of knowledge and all other 

 psychic action. The chemistry of the neuroplasm de- 

 termines the vital function of the phronema. The same 

 must be said of its most perfect and enigmatic function, 

 consciousness. Although this greatest wonder of life 

 is only directly accessible by the introspective method, 

 or by the mirroring of knowledge in knowledge, never- 

 theless the use of the comparative method in psychology 

 leads us to believe confidently that the lofty self- 

 consciousness of man differs only in degree, and not in 

 kind, from that of the ape, dog, horse, and other higher 

 mammals. 



Our monistic conception of the nature and seat of the 

 soul is strongly confirmed by psychiatry, or the science 

 of mental disease. As an old medical maxim runs, 

 Pathologia physiologiam illustrat — the science of disease 

 throws light on the sound organism. This maxim is 

 especially applicable to mental diseases, for they can all 

 be traced to modifications of parts of the brain which 

 discharge definite functions in the normal state. The 

 localization of the disease in a definite part of the 

 phronema diminishes or extinguishes the normal mental 



19 



