202 ANIMAL FORCES. [ii. 



tlie animal itself produces internal impressions^ and arranges 

 them by means of spontaneous or volitional or even free-will 

 conceptions^ the sentient actions result according to laws entirely 

 different from those of the automatic necessity just described 

 (119, 121), and are subject to the will and reason of the animal. 

 When a lobster gets one of its legs accidentally fixed in one of 

 its claws, and the claw is then made to contract by a mere 

 stimulus solely, the leg is crushed, and the animal is excited to 

 tear away the leg by the external impression of the forcible crush- 

 ing, and is thereby mutilated for a long time without suffering. 

 But if the closure of the claws and the insertion of the leg 

 between them were sentient actions from conceptions, its mind 

 would readily have deduced a third conception, namely, to open 

 the claws, and withdraw the leg. But as this does not occur, 

 the purely automatic actions are excited, and the animal loses 

 a limb in virtue of the working of a piece of mere animal 

 machinery, which it need not have lost, if the movements re- 

 sulting from its external impressions had been at the same 

 time sentient actions from its conceptive force. In such 

 cases, in sentient animals, the conceptive force regulates the 

 movements by means of internal impressions, although im- 

 pressions from mere animal stimuli may have the same effect 

 automatically. 



372. Having considered the relation of the vis nervosa to 

 the animal-sentient forces, it becomes necessary to show the 

 special seat of the former. The animal- sentient forces, whose 

 seat is the sentient brain, extend their operations as well into 

 the animal machines, as (through these) into the mechanical 

 (117). The proper seat of the vis nervosa is the nerves, for all 

 primary animal forces have their seat in animal machines only 

 (6), although they are transmitted through the animal machines 

 into the mechanical, and excite animal actions therein (7). The 

 proper animal machines are the brain and nerves, in which the 

 vital spirits are contained (9) . But the operations of the brain as 

 a sentient animal machine, are for the most part only sentient 

 actions (25). Consequently, its peculiar animal forces are animal- 

 sentient forces (6). Now, the two kinds of vis nervosa are not 

 animal-sentient forces (356), consequently, are not peculiar to 

 the brain ; and since the nerves supplied with vital spirits are 

 the only true animal machines, except the sentient brain and 



