INDUCTIVE EPOCH OF KEPLER. 433 



the most signal triumphs. Perhaps one or two 

 reflections may in some measure reconcile us to 

 this result. 



In the first place, we may observe that the 

 leading thought which suggested and animated all 

 Kepler's attempts was true, and we may add, saga- 

 cious and philosophical ; namely, that there must 

 be some numerical or geometrical relations among 

 the times, distances, and velocities of the revolving 

 bodies of the solar system. This settled and con- 

 stant conviction of an important truth regulated all 

 the conjectures, apparently so capricious and fanci- 

 ful, which he made and examined, respecting par- 

 ticular relations in the system. 



In the next place, we may venture to say, that 

 advances in knowledge are not commonly made 

 without the previous exercise of some boldness and 

 license in guessing. The discovery of new truths 

 requires, undoubtedly, minds careful and scrupulous 

 in examining what is suggested ; but it requires, no 

 less, such as are quick and fertile in suggesting. 

 What is Invention, except . the talent of rapidly 

 calling before us many possibilities, and selecting 

 the appropriate one? It is true, that when we 

 have rejected all the inadmissible suppositions, they 

 are quickly forgotten by most persons; and few 

 think it necessary to dwell on these discarded hypo- 

 theses, and on the process by which they were con- 

 demned, as Kepler has done. But all who discover 

 truths must have reasoned upon many errors, to 

 VOL. i. F F 



