824 THE POPULAR SCIENCE MONTHLY. 



analogous to those which we have observed in animals, to errors 

 of the senses, and to other illusions of the reasoning faculty. 



From the hen that sits on its empty nest to the problem of 

 Zeno the Eleatic, there runs through animals and men a continu- 

 ous series of errors, all of which have a common origin in the 

 working of the nervous system conformably to the majority of 

 cases without regarding any certain special and exceptional case, 

 The typical character of these errors is related to the phylogenic 

 development, and casts a degree of light on the unfolding of 

 thought. — Translated for the Popular Science Monthly from the 

 Revue Scientifique. 



»«» 



THE PLEASURE OF MOTION. 



By M. P. SOUEIAOU. 



MOTION gives both physical and moral pleasure. Physically, 

 it enables us to remove ourselves for the moment from 

 pain. Morally, it furnishes a satisfaction for our self-love, which 

 is remarked especially in play and in our struggles against the 

 forces of nature. 



Before being a source of positive pleasure, our physical activ- 

 ity is stimulated by pain. Those movements, called spontaneous, 

 which are the first signs of vitality in the child or animal, are ex- 

 plained by supposing them to be the reflex of some indefinite dis- 

 comfort. Our organism is not a machine, as some say, in any of 

 its parts, but is living and animated throughout. Even the organs 

 that perform without the intervention of the will, and the play of 

 which seems to be mechanical because it is not accompanied with 

 a recognizable sensation, may have the rhythm of their move- 

 ments determined by some local sensibility. 



When I feel any suffering, I have only to execute some motion, 

 to feel it less. Motion is the best of anaesthetics. It disperses at 

 a stroke all the little uneasinesses that accompany even the nor- 

 mal working of our organs, and which we experience when we are 

 occupied only with feeling ourselves live. When we make an 

 energetic effort, we are nearly insensible to pain as long as it lasts. 

 When I am at rest, a blow on the shoulder will hurt me. In the 

 ardor of sport, in the excitement of a violent exercise, the rough- 

 est shock will hardly be felt. Every very intense sensation, we 

 also know, provokes convulsive movements, sudden and violent 

 muscular contractions. These movements are not mechanically 

 determined by the sensation ; they are produced voluntarily, al- 

 though they will not remove the cause of the pain, at least to 

 mitigate its effect. The howling of the wounded dog, the squirm- 

 ing of the worm that is cut in two, are a voluntary effort to escape 

 suffering. 



