2 CHARLES DARWIN 



the case with those extraordinary waves of mental 

 upheaval, one of which gave us the Italian renaissance, 

 and another of which is actually in progress around us 

 at the present day. They have their sources deep 

 down in the past of human thought and human feeling, 

 and they are themselves but the final manifestation of 

 innumerable energies which have long been silently agi- 

 tating the souls of nations in their profoundest depths. 

 Thus, every great man may be regarded as possess- 

 ing two distinct lines of ancestry, physical and spiritual, 

 each of which separately demands elucidation. He 

 owes much in one way to his father and his mother, 

 his grandfathers and his grandmothers, and his remoter 

 progenitors, from some or all of whom he derives, in 

 varying degrees and combinations, the personal qualities 

 whose special interaction constitutes his greatness and 

 his idiosyncrasy ; he owes much in another way to his 

 intellectual and moral ancestors, the thinkers and 

 workers who have preceded him in his own department 

 of thought or action, and have made possible in the 

 course of ages the final development of his special revo- 

 lution or his particular system. Viewed as an indivi- 

 dual, he is what he is, with all his powers and faculties 

 and potentialities, in virtue of the brain, the frame, the 

 temperament, the energy he inherits directly from his 

 actual ancestors, paternal and maternal; viewed as a 

 factor or element in a great movement, he is what he 

 is because the movement had succeeded in reaching 

 such and such a point in its progress already without 

 him, and waited only for such and such a grand and 

 commanding personality in order to carry it yet a step 

 further on its course of development. 



