PROGRESSION OF ANIMALS, iv. 



motion ; and if it be placed on that which causes 

 and is the origin of movement, it will either not be 

 moved at all or with greater difficulty. The manner 

 in which we step out also shows that the origin of 

 movement is in the right side ; for all men put the 

 left foot foremost, and, when standing, preferably 

 place the left foot in front, unless they do otherwise 

 accidentally. For they are moved, not by the foot 

 which they put in front, but by that with which they 

 step off; also they defend themselves with their 

 right limb>. Therefore the right is the same in all ; 

 for that from which the oria;in of movement is derived 

 is the same in all and has its position by nature in the 

 same place, and it is from the right that the origin 

 of movement is derived. For this reason, too, the 

 stromboid testaceans all have their shells on the 

 right ; for they all move not in the direction of the 

 spiral but in the opposite direction, the purple-fish, 

 for example, and the trumpet-shell. Since, then, 

 movement in all animals starts from the right, and 

 the right moves in the same direction as the animal 

 itself, they must all alike be right-sided." Now man 

 more than any other animal has his left limbs de- 

 tached, because of all animals he is most in accord- 

 ance with nature, and the right is naturally better 

 than the left and separated from it. Therefore the 

 right is most right-sided in man. And since the right 

 is differentiated, it is only reasonable that the left is 

 less easily set in motion and most detached in man. 

 Moreover the other principles,^ the superior and the 

 front, are in man most in accord with nature and most 

 differentiated. 



* The dpxai here are the dLaardaeis of 701 b 19, 705 a 26, 

 from the point of view of function rather than position. 



495 



