CHAPTER III. 



ON THE INFLUENCE OF THE ANIMAL-SENTIENT FORCES IN THE 

 MECHANISM OF ANIMAL ORGANISMS. 



153. In the foregoing chapter, we have treated of the animal- 

 sentient forces abstractedly, without reference to their influence 

 in the mechanical machines of the body. We must now bring 

 this influence under notice (8), as being the second class of 

 actions, which the material ideas excite in the animal eco- 

 nomy (16, 113). According to § 117, we have to inquire into : 



i. The direct actions of the material ideas, which they alone 

 perform in the mechanical machines of the brain, without the 

 aid of the nerves (153 — 159). 



ii. The indirect actions of the material ideas through the 

 nerves in the mechanical machines generally (344), and spe- 

 cially the material ideas of all the various kinds of conceptions. 



Actions of Material Ideas in the Mechanical Machines 

 of the Brain. 



153. The mechanical machines of animal organisms are 

 capable of many kinds of movement, in virtue of their struc- 

 ture ; but they are put in motion much more by animal than 

 physical and mechanical forces. Since the animal forces are 

 not regulated in their operation according to physical or me- 

 chanical laws (7), we cannot bring them into the same category ; 

 and as their laws are unknown, we can only infer their actions 

 in the animal machines from observation. 



154. The influence of the soul on the body is exercised 

 by means of the material ideas, or the impressions of their 

 conceptions in the brain (25, 121), and all the movements 

 of mechanical machines which are actually efi*ected through 

 these, are sentient actions (97). All sentient actions in the 

 mechanical machines are excited either directly, by the material 

 ideas developed in the brain itself, or indirectly, by means of 



