INDISTINCTNESS OF IDEAS. 259 



of the best mathematicians of the Alexandrian 

 school; and, on subjects where his ideas were so 

 indistinct, it is not likely that any much clearer 

 were to be found in the minds of his contempo- 

 raries. Accordingly, on all subjects of speculative 

 mechanics, there appears to have been an entire 

 confusion and obscurity of thought till modern 

 times. Men's minds were busy in endeavouring 

 to systematize the distinctions and subtleties of 

 the Aristotelian school, concerning Motion and 

 Power ; and, being, thus employed among doctrines 

 in which there was involved no definite meaning 

 capable of real exemplification, they, of course, 

 could not acquire sound physical knowledge. We 

 have already seen that the physical opinions of 

 Aristotle, even as they came from him, had no 

 proper scientific precision. His followers, in their 

 endeavours to perfect and develop his statements, 

 never attempted to introduce clearer ideas than 

 those of their master ; and as they never referred, 

 in any steady manner, to facts, the vagueness of 

 their notions was not corrected by any collision 

 with observation. The physical doctrines which 

 they extracted from Aristotle were, in the course 

 of time, built up into a regular system ; and though 

 these doctrines could not be followed into a prac- 

 tical application without introducing distinctions 

 and changes, such as deprived the terms of all 

 steady signification, the dogmas continued to be 

 repeated, till the world was persuaded that they 



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