THE human mind has been young ; it was poor, but it has become 

 rich ; it was ignorant of what it now knows. Ideas have been 

 .successively gathered together, heaped up ; they have mutually 

 engendered each other, the one has led to another. It remains 

 therefore merely to rediscover this succession, to begin with the 

 earliest ideas ; the path is traced out ; it is a journey that one 

 may make again because it has already been made ; the individual 

 may now cover in the course of some hours' reading an extent of 

 knowledge which it has cost the race long centuries to acquire. 



BAILLY, Histoire de I'Astronomie Moderns. 



