CHAPTER VI. 



Disease not an Entity — All Disease comes through E — The Variability of 

 Disease — A Perfect Classification Impossible. 



There is a tendency to regard diseases as fixed and unchange- 

 able types, or, if varying, as varying within narrow limits only. 

 This belief still clings to us as a relic of the past, for it pro- 

 bably arose out of the old notion that diseases were separate 

 and independent entities. 



At that period of his evolution when man was first able to 

 reason on the subject of disease, he attributed it, as he did all 

 the various phenomena of nature, to some spiritual agency. To 

 him a disease was an evil spirit which had taken up its abode 

 in his body, and all his attempts at cure had for their object 

 the driving out of the unclean thing — the exorcism of the 

 spirit. Later on, the belief in spiritual agencies gave way to 

 the theory of humours, which, resting though it did but very 

 slenderly on fact, was yet more in accord with his wider 

 knowledge of natural processes. 



We shall presently see that both these views, crude and 

 fanciful though they are, had more of truth in them than a 

 hasty consideration would lead us to believe. One thing, how- 

 ever, is quite certain — viz., that it is impossible to regard disease 

 as a separate entity, as something capable of mechanical sepa- 

 ration from the body, of being corked up, as it were, in a bottle. 

 One might, perhaps, be inclined so to regard it in such a case 

 as "tapeworm," for here the mal-E consists of a worm, which, 

 taking up its abode within the body, produces a series of 

 symptoms, all of which disappear with the disappearance of 

 the nocuous agent. In this case, however, the disorder con- 

 sists, not of the tapeworm, but of the abnormal inter- actions 

 which are set up by it — of improper inter-action, be it noted, of 

 S and E. The tapeworm no more constitutes the disorder 



