100 ANIMAL-SENTIENT FORCES. [i. 



According to this view^ external sensations must be considered 

 as watching over our preservation. 



185. Again, we often confound the sentient actions in the 

 mechanical machines, resulting from other conceptions, with 

 those resulting directly from external sensations. When we 

 smell or see some nauseous article of food, which, on some 

 previous occasion has made us vomit, the external sensation 

 excites in us the imagination of the previous vomiting, and it 

 again comes on, because this imagination conjoins with it in 

 its action the partially re-excited external sensation {67). In 

 this case, vomiting is not the immediate result of the smell, or 

 perception (the external sensation) of the article of food, but 

 of the imagination thereby excited. When we see a stone 

 coming upon us and try to avoid it, the movement is not a 

 direct sentient action excited by the seeing the stone (the ex- 

 ternal sensation), but is the result of the abhorrence of the 

 impending danger, which the sight of the stone occasions. 

 Such examples are infinitely numerous, and if we compare 

 them with those mentioned in ^ 182, it is found that we have 

 mistaken the greater number for the movements connected 

 directly with external sensations, these being either nerve- 

 actions also, or purely nerve-actions (182, 183), or sentient 

 actions of other mental forces which are excited to action solely 

 by external sensations (219, 199). 



186. It is to be understood, however, that those inner sen- 

 sations of the soul of pleasure and suffering excited by external 

 sensations (80) must, on no account, be classed with the con- 

 ceptions produced by external sensations, the sentient actions of 

 which are so often confounded with those belonging to external 

 sensations ; for pleasure and suffering are only qualities in the 

 external sensations of the soul, and not other conceptions excited 

 by them ; their sentient actions are consequently to be classed 

 with those arising directly from external sensations, and they 

 extend their influence to no other nerves than those which feel 

 the agreeable or disagreeable (124). But since the two distinct 

 conditions of agreeable and disagreeable external sensations con- 

 stitute external sensations for two distinct kinds of conceptions, 

 and these presuppose distinct material sensations in the brain 

 (80), and, consequently, distinct external impressions in the 

 nerves (35), they certainly constitute two perfectly distinct 



