154 ANIMAL-SENTIENT FORCES. [i. 



actions in the parts appropriated to the animal-sentient forces, 

 so that it develops imperfectly the future state of repose (271); 

 and in fact, in the straining of the animal-sentient forces and 

 the effort of the mind to withdraw as much as possible from 

 all external sensations, and spontaneous conceptions, and thereby 

 to interrupt all their sentient actions in the body, consists the 

 sentient actions of the instinct to repose itself (272), so that 

 the organs which co-operate in the act of thinking, and which 

 produce sentient actions, are compelled involuntarily, by the 

 soul and by a purely corporeal process, to cease their functions 

 (270, 49, 51). Consequently, during the instinct to repose and 

 sleep, the external sensations derived from external impressions, 

 and from the spontaneous conceptions are gradually lost, in 

 consequence of the enfeebling of their material ideas in the 

 brain; the muscles, in so far as they perform sentient actions, 

 move heavily, and let the limbs sink ; the eyelids shut, and the 

 whole body totters. In short, the instinct induces imperfectly 

 that condition which comes on when the instinct is satisfied by 

 rest or sleep, and there results from the connection between 

 the physical, mechanical, and animal forces, the repose and 

 renewal of the forces appropriate to sentient actions, in accord- 

 ance with the object of nature in establishing the instinct {vide 

 Haller's 'Physiology,' §§ 578—590). 



ii. Yawning and stretching are rather sentient actions of the 

 instinct for exhilaration, than for rest. For when we feel the 

 unpleasant condition of languor and weariness, we can attain 

 its opposite by new efforts of the animal-sentient forces, as well 

 as by their periodical relaxation during sleep. If, therefore, the 

 obscure stimulus leads us to the former, we then express the 

 anticipated condition of renewed activity of the animal-sentient 

 forces, by imperfect efforts, to which the agreeable obscure 

 foreseeing of the condition of activity excites us. Consequently, 

 although these movements are doubtless signs of weariness, and 

 of the need for sleep, yet they are not sentient actions of the 

 instinct for sleep, but of the instinct for activity, or the waking 

 state. All circumstances that excite the obscure foreseeing of 

 pleasing exhilaration, and, consequently, the above-mentioned 

 causes of weariness render the instinct active, if we desire 

 the antagonistic condition, namely exhilarated activity. Now, 

 as the sight of another person who yawns or stretches him- 



