INTRODUCTION. 

 Of Formal and Physical Astronomy. 



WE have thus rapidly traced the causes of the almost complete blank 

 which the history of physical science offers, from the decline of 

 the Roman empire, for a thousand years. Along with the breaking 

 up of the ancient forms of society, were broken up the ancient energy 

 of thinking, the clearness of idea, and steadiness of intellectual action. 

 This mental declension produced a servile admiration for the genius of 

 the better periods, aud thus, the spirit of Commentation : Christianity 

 established the claim of truth to govern the world ; and this principle, 

 misinterpreted and combined with the ignorance and servility of the 

 times, gave rise to the Dogmatic System : and the love of speculation, 

 finding no secure and permitted path on solid ground, went off into 

 the regions of Mysticism. 



The causes which produced the inertness and blindness of the sta- 

 tionary period of human knowledge, began at last to yield to the in- 

 fluence of the principles which tended to progression. The indistinct- 

 ness of thought, which was the original feature in the decline of sound 

 knowledge, was in a measure remedied by the steady cultivation of 

 Pure Mathematics and Astronomy, and by the progress of inventions 

 in the Arts, which call out and fix the distinctness of our conceptions 

 of the relations of natural phenomena. As men's minds became clear, 

 they became less servile : the perception of the nature of truth drew 

 men away from controversies about mere opinion ; when they saw 

 distinctly the relations of things, they ceased to give their whole atten- 

 tion to what had been said concerning them ; and thus, as science rose 

 into view, the spirit of commentation lost its way. And when men 

 came to feel what it was to think for themselves on subjects of science, 

 they soon rebelled against the right of others to impose opinions upon 

 them. When they threw off their blind admiration for the ancients, 

 they were disposed to cast aw?y also their passive obedience to the 

 ancient system of doctrines. When they were no longer inspired by 

 the spirit of commentation, they were no longer submissive to the dog- 

 matism of the schools. When they began to feel that they could dis- 



