68 THE GREEK SCHOOL PHILOSOPHY. 



duces principles' of a more arbitrary character ; and besides the general 

 relations of thought, takes for granted the inventions of previous 

 speculators ; such, for instance, as the then commonly received opin- 

 ions concerning the frame of the world. From the assertion that 

 motion is eternal, proved in the manner just stated, Aristotle proceeds 

 by a curious train of reasoning, to identify this eternal motion with 

 the diurnal motion of the heavens. "There must," he says, "be 

 something which is the First Mover :" 9 this follows from the relation 

 of causes and effects. Again, " Motion must go on constantly, and, 

 therefore, must be either continuous or successive. Kow what is con- 

 tinuous is more properly said to take place constantly, than what is 

 successive. Also the continuous is better; but we always suppose 

 that which is better to take place in nature, if it be possible. The 

 motion of the First Mover will, therefore, be continuous, if such an 

 eternal motion be possible." We here see the vague judgment ot 

 better and worse introduced, as that of natural and unnatural was 

 before, into physical reasonings. 



I proceed with Aristotle's argument. 10 u We have now, therefore, 

 to show that there may be an infinite single, continuous motion, and 

 that this is circular." This is, in fact, proved, as may readily be con- 

 ceived, from the consideration that a body may go on perpetually 

 revolving uniformly in a circle. And thus we have a demonstration, 

 on the principles of this philosophy, that there is and must be a 

 First Mover, revolving eternally with a uniform circular motion. 



Though this kind of philosophy may appear too trifling to deserve 

 being dwelt upon, it is important for pur purpose so far as to exemplify 

 it, that we may afterwards advance, confident that we have done it no 

 injustice. 



I will now pass from the doctrines relating to the motions of the 

 heavens, to those which concern the material elements of the universe. 

 And here it may be remarked that the tendency (of which we are 

 here tracing the development) to extract speculative opinions from the 

 relations of words, must be very natural to man ; for the very widely 

 accepted doctrine of the Four Elements which appears to be founded 

 on the opposition of the adjectives hot and cold, wet and dry, is much 

 older than Aristotle, and was probably one of the earliest of philosophi- 

 cal dogmas. The great master of this philosophy, however, puts the 

 opinion in a more systematic manner than his predecessors. 



Physic. Ausc. via. 6. p. 253. ;o Ib. viii. 8. 



