148 ANIMAL-SENTIENT FORCES. [i. 



The Instinct to perform Sensational Voluntary Movements 

 [Zur willkuhrlichen Bewegung].^ 



283. Nature has ordained bodily exercise to be a means of 

 the preservation and well-being of animals, and thereby they 

 are kept in the best health. When therefore to its injury, 

 exercisfe of the body is too long neglected, a number of unpleasant 

 sensations are excited, termed indisposition or sickliness, and 

 which all animals abhor (280). These constitute the sensational 

 stimulus of the instinct for bodily exercise, in which the vital 

 movements are more or less morbid, according to the strength 

 of the stimulus, the pulse becoming feverish, and the respiration 

 impeded. By this unpleasant sensational stimulus (induced by 

 long repose, too much sleep, too great corpulency, and many other 

 causes), the animal is induced to make an effort for the opposite 

 agreeable sensations, which it foresees will be obtained by the 

 movement of its muscles and limbs, and this is the intent of 

 nature and the object of the instinct, although the animal does not 

 know for what ulterior purpose it makes the movements (266). 

 The sentient actions of this sensational stimulus, in so far as they 

 are a foreseeing of corporeal exercise are, consequently, developed 

 in the muscles of voluntary motion, that is to say, in those 

 which conceptional impressions can excite to movement inde- 

 pendently of any other impression, so that it stimulates those 

 muscles to the same movements that are fully performed during 

 bodily exercise (271). In the effort of the animal-sentient forces 

 to perform these movements imperfectly consists the sentient 

 actions of the instinct to bodily exercise itself (272). This 

 instinct acts, therefore, in the mechanical machines which 

 formerly exercised the body, namely, the muscles of voluntary 

 motion, for it excites them to the performance of their natural 

 functions (161 — 166), and which especially the gratification of 



* In a note to § 335, Unzer distinguishes two classes of voluntary movements, 

 namely, the willkiihrlich, or sensational, which accompany the sensations and all 

 sensational conceptions ; and the freiwillig, or intellectual, which are excited by the 

 will of the understanding. Wille and Willkiihr are also sometimes used to dis- 

 tinguish these two kinds of will, but more frequently Willkuhr is used to express 

 both, as in the note referred to, where Unzer distinguishes between the sensational 

 and intellectual Willkuhr. I know of no English word which corresponds to 

 Willkuhrlich ; I have, therefore, termed the actions of voluntary muscles to which 

 Unzer uses it in the stricter sense, sensational voluntary movements; but where 

 it is used indefinitely, I have translated it by voluntary simply, or volitional. — Ed, 



