ARISTOTELIAN PHYSICS. 65 



of the Aristotelians, that there can be no void, that things seek their 

 own place, and the like. 5 



Another mode of reasoning, very widely applied in these attempts, 

 was the doctrine of contrarieties, in which it was assumed, that adjec- 

 tives or substantives which are in common language, or in some ab- 

 stract mode of conception, opposed to each other, must point at some- 

 fundamental antithesis in nature, which it is important to study. Thus 

 Aristotle 6 says, that the Pythagoreans, from the contrasts which 

 number suggests, collected ten principles, Limited and Unlimited, 

 Odd and Even, One and Many, Plight and Left, Male and Female. Rest 

 and Motion, Straight and Curved, Light and Darkness, Good and Evil, 

 Square and Oblong. We shall see hereafter, that Aristotle himself 

 deduced the doctrine of Four Elements, and other dogmas, by opposi- 

 tions of the same kind. 



The physical speculator of the present day will learn without sur- 

 prise, that such a mode of discussion as this, led to no truths of real or 

 permanent value. The whole mass of the Greek philosophy, there- 

 fore, shrinks into an almost imperceptible compass, when viewed with 

 reference to the progress of physical knowledge. Still the general 

 character of this system, and its fortunes from the time of its founders 

 to the overthrow of their authority, are not without their instruction, 

 and, it may be hoped, not without their interest. I proceed, there- 

 fore, to give some account of these doctrines in their most fully devel- 

 oped and permanently received form, that in which they were presented 

 by Aristotle. 



Sect. 2. The Aristotelian Physical Philosophy. 



THE principal physical treatises of Aristotle are, the eight Books of 

 " Physical Lectures," the four Books " Of the Heavens," the two Books 

 " Of Production and Destruction :" for the Book " Of the World" is 

 now universally acknowledged to be spurious; and the "Meteoro- 

 logies," though full of physical explanations of natural phenomena, 

 does not exhibit the doctrines and reasonings of the school in so gen- 

 eral a form ; the same may be said of the " Mechanical Problems." 

 The treatises on the various subjects of Natural History, " On Ani- 

 mals," " On the Parts of Animals," " On Plants," " On Physiognom- 

 onics," " On Colors," " On Sound," contain an extraordinary accumu- 



6 Timoeus, p. 80. ' Metaph. 1. 5. 



VOL. I. 5 



