NUMEROUS CAUSES OF SCIENTIFIC PROGRESS. 73 



to one man ; it was not the result of a method alone : it owed 

 its birth to concurrent energies, practical in the main ; but 

 its final parturition was the work, as we have said, of the 

 great men who preceded Kepler, Galileo, and Harvey, just 

 as its culture and immense advancement after Kepler, 

 Galileo, and Harvey were the work of the great men whom 

 we shall mention the earlier and the later movements 

 being connected from beginning to end by an unmistakable 

 filiation of discoveries. The concatenation presents a series 

 of powerful links without a single break.* It is obvious at 

 a glance, especially in its main points. The discovery of 

 Copernicus, and the labours of Tycho Brahe consequent 

 upon it, prepared the way for the investigation of Kepler, 

 which constituted the true system of celestial geometry and 

 gave birth to celestial mechanics; Galileo's mathematical 

 theory of motion, and his discovery of the laws of falling 

 bodies, together with Descartes's mathematical revolution, 

 necessarily followed by Huygens's discovery of the law of 

 centrifugal force, led to Newton's final discovery. 



This brief summary suffices to demonstrate how unbroken 

 the evolvement of science was without the intervention of 

 an outside agent. The evolutionary law, in fact, worked 

 throughout the Mediaeval and Revival Periods with irresistible 

 force, and without any deviation from its natural and 

 necessary course. 



* Comte. 



