CH. III.] ACTIONS OF THE WILL. 179 



please or displease, according as the external impressions from 

 which they directly or indirectly arise, are in accordance with, 

 or contrary to, the natural function of the nerves. 



334. From an error of the understanding, the mind may 

 esteem something to be good or to be evil, which is the contrary. 

 But since in either case, nevertheless, the pleasure or pain there- 

 from is felt, it follows, according to the laws of the sentient 

 actions of both (254), that the agreeable motives will originate 

 changes favorable to health, while the disagreeable originate 

 unfavorable changes. Hence error and truth may alike some- 

 times advance, sometimes detract from, the well-being of an 

 animal ; so that in this respect, as is the case generally, it is not 

 every truth that is propitious, nor every error that is unpropitious. 



Actions of the Will through the Nerves in the Mechanical 

 Machines, 



335. When the mind wills in reference to the pleasure or pain 

 in a distinct foreseeing of the understanding, it exercises its 

 conceptive force to produce the foreseeing or its opposite (81) ; 

 and thus it wills, or not wills, from motives (88, 96). The 

 eflPorts of the cerebral forces connected with this act of willing 

 or not willing, partly express the perfect material idea of the 

 foreseen sensation (96) . If the circumstance in the intellectual 

 desire or aversion be only another spontaneous conception, 

 which has no direct influence on the mechanical machines, 

 as, for example, a general proposition (330), then the efforts 

 are limited to the development of the corresponding material 

 ideas, and the desires and aversions of the will have no 

 perceptible sentient actions, at least, on the mechanical 

 machines (332). But if the object of the act of willing, or 

 not willing, be a conception, that should act on the mechanical 

 machines, fitting material ideas are developed (96), and thus 

 the desires and aversions of the will have some sentient actions 

 in the mechanical machines (104, 110). For example, the 

 desire to comprehend a truth is manifested by no actions 

 exterior to the brain, but the desire to perform a certain act, 

 as, for instance, to rise and take hold of anything, is followed 

 by the proper movements. The sentient actions, which intel- 

 lectual desires and aversions develop directly through the 



