THE NERVOUS SYSTEM. 415 



While the brain is evidently the organ of mind, the nerves 

 united with it, and the spinal chord, together with its nerves, 

 are as evidently the instruments by which it affects, and is affected 

 by the other parts of the body, to which these nerves are dis- 

 tributed. By their instrumentality, the brain contracts the volun- 

 tary muscles, influences the functions of every other part when 

 under the operation of the different passions, and receives im- 

 pressions made upon every other part. 6 The consequences of 

 divisions of the nerves or spinal chord, fully substantiate these 

 points. 



If a nerve supplying an organ of sense, as the olfactory, optic, 

 acoustic, or gustatory, is compressed or divided, the organ be- 

 comes insensible to odours, light, sounds, or tastes. If one exciting 

 muscles only, as the common motor oculi, the internal or the 

 external motor, the facial or the hypoglossal, the will loses 

 power over such muscles ; over the inferior, superior, and internal 



extensive influence which my doctrine will one day exert upon human know- 

 ledge ; for which reason I have remained indifferent to all the good or evil which 

 might be said of my labours. They were too far removed from received opinions 

 to be relished and approved at first. A knowledge of them required profound 

 and continued study : every one wished to pronounce upon them, and every one 

 came with opinions and views according to his means of intelligence. All 

 the doctrine is now consecrated to the public. Judgment cannot long remain 

 doubtful. Personal feeling will disappear: the passions will calm, and criticism 

 will have only its due weight. Posterity will not fail to contrast the point 

 from which I started with that at which I stopped. My adversaries have but too 

 distinctly displayed the state in which the various objects of my labours were, 

 for it to be difficult to know what improvement these have derived and will de- 

 rive from my discoveries. What progress in the comparative anatomy, physio- 

 logy, and pathology of the nervous system ! What a fruitful source of irre- 

 fragable principles for philosophical studies ; for the art of learning the disposition 

 of individuals to the best advantage ; for the art of directing the education of 

 youth ! What valuable materials for criminal legislation, based upon a complete 

 knowledge of the motives of human action ! How history will change in the 

 eyes of those who will know how to value it according to the predominant inclin- 

 ations and faculties of the personages who have played the chief parts in it," &c. 

 (1. c. 4to. vol. iii. p. xii. sq., 8vo. t. vi. p. viii. sq.) 



e In strict language, no part of the body but the encephalon, or what corre- 

 sponds to it in lower animals, can have sensation. The different parts may be so 

 affected, that, by the intervention of nerves between them and the encephalon, 

 the latter perceives the impression made upon them ; but the sensation is in the 

 encephalon, although instinctively referred to the spot which is its source. 



F F 



