56 THE GREEK SCHOOL PHILOSOPHY. 



The reader will still perceive the verbal founda- 

 tions of opinions thus supported. 



" The simple elements must have simple motions, 

 and thus fire and air have their natural motions 

 upwards, and water and earth have their natural 

 motions downdards; but besides these motions, there 

 is motion in a circle, which is unnatural to these 

 elements, but which is a more perfect motion than 

 the other, because a circle is a perfect line, and a 

 straight line is not; and there must be something 

 to which this motion is natural. From this it is 

 evident," he adds, with obvious animation, "that 

 there is some essence of body different from those 

 of the four elements, more divine than those, and 

 superior to them. If things which move in a circle 

 move contrary to nature, it is marvellous, or rather 

 absurd, that this, the unnatural motion, should alone 

 be continuous and eternal ; for unnatural motions 

 decay speedily. And so, from all this, we must col- 

 lect, that besides the four elements which we have 

 here and about us, there is another removed far 

 off, and the more excellent in proportion as it is 

 more distant from us." This fifth element was the 

 " quinta essentia" of after writers, of which we have 

 a trace in our modern literature, in the word quint- 

 essence. 



