326 ADDRESS DELIVERED TO THE 



disease consists essentially in the adjustment of previously 

 altered conditions of health, and that the part which you 

 have to take in the recovery of those who may require your 

 assistance is therefore altogether indirect and secondary. 



If the conditions on which health and life depend were 

 merely material, — if the forces which are at work within the 

 organised system itself, and which associate it with the ex- 

 ternal medium in which it lives, were only such as the chemist 

 and physicist can investigate and determine, — then the pro- 

 blem of health and longevity would be comparatively simple. 

 The next difficulty in your art consists, therefore, in this, that 

 within the living economy you have to deal with powers 

 which cannot be measured, weighed, or subjected to calculation, 

 but which nevertheless exercise an influence there co-ordinate 

 with the working of its material forces. As this double sphere 

 of action is the leading characteristic of the organised being, 

 so it on the one hand affords the distinctive mark of organic 

 science, and on the other constitutes the peculiar difficulty of 

 medical art. Hence we may infer, as another general prin- 

 ciple in medicine, that in the treatment of disease, the adjust- 

 ment may require to he, and in general must he, directed more 

 or less as well to the psychical as to the physical conditions of 

 the case. 



As man is distinguished from all the other organised beings 

 in the midst of which he is placed by the comprehensiveness 

 of the conditions of his economy, he is also peculiar in the 

 mode in which he is enabled to provide for them. His pecu- 

 liarity consists not so much in the complexity of his corporeal 

 frame, as in the character and sphere of his consciousness. 

 The conscious principle, if the expression may be so applied, 

 of the horse or dog, is influenced only by external circum- 

 stances ; the sphere of its activity is, so to speak, altogether 

 external to itself; impressible from without, and therefore, in 

 some sort, conscious of surrounding objects, it is altogether 



