POPULAR SCIENCE 263 



sensation. The concept is thus nothing but a registered over- 

 tone.^ 



There are good reasons for assuming that all nerve impulses 

 are rhythmical in nature, and that the Psychic functions are 

 no exception to the production of overtones. Hence new 

 Psychic overtones are ever in the process of formation. The 

 more our powers of mental assimilation are perfected, the more 

 the properties and complexities of that concept belong to the 

 causative object ; if a person learns a language indifferently, 

 his attempts to speak in this language reveal characteristics 

 that are peculiar to himself. When he has mastered that 

 language, some of his eloquence may still belong to himself, but 

 his personal errors or aberration from the conventionalities of 

 that language have diminished, and his exposition belongs 

 more to the language than to himself. So it is with all know- 

 ledge : in its imperfection it contains the errors belonging to 

 the Human Race ; as it becomes more perfected it necessarily 

 belongs more and more to the object — Nature. 



A physician can see this truth well in a case of aphasia. 

 Take, for instance, such a case where the motor speech centres of 

 the brain have been partially destroyed by disease ; the patient 

 cannot produce speech ; he can write to dictation, though not 

 spontaneously ; his attempts at reading, pronouncing, and 

 spontaneous writing, faulty and laborious, are due to his faulty 

 self ; but when these faults and incapacities have been corrected, 

 when the adjacent parts of the brain have been educated to 

 meet the requirements, he can more faithfully pronounce and 

 write the thoughts emanating from his higher centres, and more 

 accurately read what is written before him. A condition known 

 as syringomyelia, where an individual is born without the 

 nerve-channels capable of conveying thermal impressions to 

 the brain, will render overtones relative to the temperature of 

 an object impossible of formation : a block of ice and a hot- 

 water bottle fail to produce the normal impression in the 

 patient's mental complex, where the knowledge of the natural 

 phenomena of heat is so wanting as to render the unconscious 

 self-infliction of burning of frequent occurrence in such cases. 

 The assortment of certain forces in the mental complex has here 

 been impossible owing to the lack of the material channels. 



Similarly, in the treatment of a case of cretinism, where the 

 development of the potential mental complex has not taken 

 place on account of the absence of the requisite molecularly 



^ Cf. Science Progress, January 1920, p. 475 : " The combination of the 

 movement of thought, so that the successive conditions may be produced, 

 depends on an extraordinarily compUcated underlying mechanism, the 

 physical correlative to the mental state ; and the successive impacts giving 

 rise to new mental states." 



