322 LAY SERMONS, ADDRESSES, AND REVIEWS. [xiv. 



varied experience ; in testing myself by the chances of fortune ; and 

 in always trying to profit by rny reflections on what happened. . . . 

 And I always had an intense desire to learn how to distinguish truth 

 from falsehood, in order to be clear about my actions, and to walk 

 surefootedly in this life." 



But "learn what is true, in order to do what is right," 

 is the summing up of the whole duty of man, for all 

 who are unable to satisfy their mental hunger with the 

 east wind of authority ; and to those of us moderns who 

 are in this position, it is one of Descartes' great claims to 

 our reverence as a spiritual ancestor, that, at three-and- 

 twenty, he saw clearly that this was his duty, and acted 

 up to his conviction. At two-and-thirty, in fact, finding 

 all other occupations incompatible with the search after 

 the knowledge which leads to action, and being possessed 

 of a modest competence, he withdrew into Holland ; 

 where he spent nine years in learning and thinking, in 

 such retirement that only one or two trusted friends 

 knew of his whereabouts. 



In 1637 the firstfruits of these long meditations were 

 given to the world in the famous " Discourse touching 

 the Method of using Eeason rightly and of seeking 

 scientific Truth," which, at once an autobiography and a 

 philosophy, clothes the deepest thought in language of 

 exquisite harmony, simplicity, and clearness. 



The central propositions of the whole " Discourse " are 

 these. There is a path that leads to truth so surely, that 

 any one who will follow it must needs reach the goal, 

 whether his capacity be great or small. And there is one 

 guiding rule by which a man may always find this path, 

 and keep himself from straying when he has found it. 

 This golden rule is — give unqualified assent to no pro- 

 positions but those the truth of which is so clear and 

 distinct that they cannot be doubted. 



The enunciation of this great first commandment of 



