1 66 THE CAUSATION OF DISEASE. 



enumerate all the causes which would directly or indirectly tend 

 to ignite the very ample supply of neurotic dynamite, and 

 which would, therefore, have to be included under the specific 

 pathogenesis. 



It would, of course, be possible for the disease to be called 

 forth by a more powerful exciting cause — e.g., E 5 ; but in such 

 a case the excess of E (three) is in a manner inoperative. 

 For, speaking, as we are, of the pathogenesis of insanity 

 without any regard to the intensity of the morbid action, we 

 cannot get more than I r, since this number represents the 

 full disease. No doubt a greater quantity of specific mal-E — 

 e.g., prolonged mal-hygiene — might induce a more intense at- 

 tack of the disease, and we might represent this by S 9 + E 10 = 

 ig, but I am not attempting to represent numerically the 

 intensity of the disease ; I am dealing only with the actual 

 presence or absence thereof, the number 1 1 , or any higher 

 number, denoting the presence of insanity, the numbers below 

 this its absence. It would, perhaps, be possible, however, to 

 somewhat roughly denote in this numerical way the intensity — 

 the dose, if we may so put it — of the malady. Thus the most 

 hopeless case of insanity might be represented thus : S 10 + E 10 . 

 Here we have nine units in excess of the minimum quantity 

 of genesis, and this formula would signify that an individual 

 in whom the tendency to insanity was very rife had been sub- 

 jected to the largest possible quantity of insanity-producing E. 

 Let it be noted that a specific pathogenesis dates from the 

 earliest period of life. It is well known, e.g., that many neuroses 

 attend rickets, and this may be the starting-point of very 

 serious nervous disorders in after-life. 



To return to the symbols: S s . 5 -fE.. 5 would indicate that 

 each vital factor takes an equal share in causation ; S x + E 10 , 

 that an exposure to the largest possible quantity of specific 

 mal-E is needed to call out the disease ; while S + E 10 implies 

 that the individual refuses to become insane, even though he be 

 rigorously subjected to every possible insanity-producing cause. 

 Some may think no such individual exists. It might be 

 argued, for instance, that insanity can always be induced by 

 traumatic causes. It is, however, only exceptionally that such 

 a result follows upon a head injury. By voluntarily disor- 



