IV 



ON DESCARTES' "DISCOURSE TOUCHING 

 THE METHOD OF USING ONE'S 

 REASON RIGHTLY AND OF SEEKING 

 SCIENTIFIC TRUTH" 



[1870] 



IT has been well said that " all the thoughts of 

 men, from the beginning of the world until now, 

 are linked together into one great chain ; " but the 

 conception of the intellectual filiation of mankind 

 which is expressed in these words may, perhaps, 

 be more fitly shadowed forth by a different 

 metaphor. The thoughts of men seem rather to 

 be comparable to the leaves, flowers, and fruit 

 upon the innumerable branches of a few great 

 stems, fed by commingled and hidden roots. 

 These stems bear the names of the half-a-dozen 

 men, endowed with intellects of heroic force and 

 clearness, to whom we are led, at whatever point 

 of the world of thought tin- attempt to trace its 



