ARISTOTELIAN PHYSICS. 43 



The physical speculator of the present day will 

 learn without surprise, that such a mode of discus- 

 sion as this, led to no truths of real or permanent 

 value. The whole mass of the Greek philosophy, 

 therefore, shrinks into an almost imperceptible com- 

 pass, 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, therefore, to give 

 some account of these doctrines in their most fully 

 developed 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 Pro- 

 duction and Destruction:" for the Book "Of the 

 World" is now universally acknowledged to be 

 spurious ; and the " Meteorologies," though full of 

 physical explanations of natural phenomena, does 

 not exhibit the doctrines and reasonings of the 

 school in so general 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 Physiognomonics," "On Colours," "On Sound," 



