294 ANIMAL FORCES. [ii. 



newly-born child, after being washed with wine, moves its 

 limbs, having its circulation accelerated, &c., just as would 

 have followed from the taking of wine; or when a headless 

 butterfly is excited to copulation, by the fluttering of the 

 female, just as if the sexual sensation had been excited in it. 



570. Who can doubt, that the sentient actions of sorrow 

 (310, 312) may be induced by the vis nervosa only ? Yet if 

 we were to trace them back in the majority of cases to the 

 primary sensation, and attempt to deduce them from their 

 external impressions only, namely, from the nerve-actions of 

 black bile in the stomach and bowels, of imperfect digestion, 

 &c., in the order in which they arise, together with their 

 material results in the economy, such as diminished transpira- 

 tion, weeping, wailings, &c., we should find no examples in 

 which it could be done, except in instances in which they 

 arise directly from the external sensation. In this way, a child 

 cries from the first external impression of the air, as if suffering 

 pain, a decapitated man clasps his hand, when wounded, as if 

 lamenting, &c. 



571. The sentient actions of all kinds of fear, anguish, 

 despair, and terror (314 — 320), may also be excited by the 

 vis nervosa solely ; still, as in the preceding cases, they cannot 

 be traced directly back in the order in which they arise to the 

 primary sensation, and thence to the external impressions 

 causing them, except in the instances in which they arise (as 

 in instinctive actions) immediately from the external sensation, 

 and of which illustrations have been already given (566). 



572. Lastly, the sentient actions of all kinds of anger and 

 revenge (323 — 325), may be excited by the vis nervosa only; 

 still, as in the preceding instances, they cannot be traced back 

 to their primary exciting impression, except when they are 

 instinctive in their nature, and arise directly from an external 

 sensation. 



573. In investigating the sentient actions of all the other 

 passions, and other desires and aversions, the material ideas of 

 all the intervening sensational conceptions must be considered 

 (111, 568, i, ii). The sentient actions of the true passions 

 (306, 309), can never occur in decapitated animals, solely by 

 means of the vis nervosa, or in those not endowed with mind, 

 or capable at most of only feeble and obscure external sensa- 



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