134 ANIMAL-SENTIENT FORCES. [i. 



the instinct. In cases of this kind, the nerves themselves 

 appear to change their nature and to favour the instinct, since 

 they receive new impressions and stimuli, from which they 

 were previously secured ; and, lastly, experience also sufficiently 

 shows to us, how little all psychological means avail in weak- 

 ening the desires and aversions, when moralists apply them to 

 human nature, with the object of preventing the outbreak or satis- 

 faction of its feelings, or restraining them within certain limits. 

 266. The sensational instincts act in the mechanical machines 

 in accordance with this preordained arrangement, established 

 by the wisdom of the Creator in the whole creation, as well as 

 in the animal kingdom, for their development and for the 

 attainment of their main objects. They are in no way dependent 

 upon an innate wisdom present in the mind of the animal, by 

 which it spontaneously and voluntarily excites these instincts, 

 and their operations in the body (89, 90). And indeed, those 

 actions which in true sensational animals are sentient actions of 

 the sensational instincts, are excited in other animals, or in the 

 former under circumstances in which they can no longer be sen- 

 tient actions, by precisely the same external impressions (183) : 

 as, for example, when a decapitated animal being brought to 

 another, copulates and lays eggs ; when a decapitated frog with- 

 draws its leg on its foot being pinched, and leaps away, in 

 accordance with the instinct of self-preservation, &c., of which 

 more in the Second Part of the work. It is manifest, also, that 

 although these animals, in which the instinctive actions are sen- 

 tient actions, feel the sensational stimuli so strongly, although 

 obscurely, as to long for their gratification, they have not the 

 least knowledge of the objects of the instincts, or why these 

 movements are produced; but, on the contrary, their other 

 actions are not in harmony with those objects, and this is the 

 reason why so much surprise is felt at the stupidity of animals, 

 which otherwise display so much apparent sagacity in the actions 

 appropriate to their natural instincts ; as, for example, when a 

 hen, which has trod upon her chicken, hearing its cry, calls it 

 to some food, without at the same time lifting its foot ; or when 

 a lobster having one of its legs fixed in and pinched by one of 

 its claws, excited by the pain, violently tears away the limb, 

 instead of opening its claw ; or, when a lark, while over the sea, 

 blindly following its instinct to ascend into the air, and to fall 



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