PREFACE vii 



political life touched the lowest depths of degra- 

 dation, amidst the chaotic personal intrigues of 

 the Fronde. Thus endowed, thus nurtured, thus 

 tempered in the fires of experience, it is intelli- 

 gible enough that a resolute, clear-headed man, 

 haunted from his youth up, as he tells us, with 

 an extreme desire to learn how to distinguish 

 truth from falsehood, in order to see his way 

 clearly and walk surely through life,* should have 

 early come to the conclusion, that the first thing to 

 be done was to cast aside, at any rate temporarily, 

 the crutches of traditional, or other, authority; 

 and stand upright on his own feet, trusting to no 

 support but that of the solid ground of fact. 



It was in 1619, while meditating in solitary 

 winter quarters, that Descartes (being about the 

 same age as Hume when he wrote the " Treatise on 



O ^WM^IWB^g^^ 



Human Nature ") made that famous resolution, to 

 " take nothing for truth without clear knowledge 

 that it is such/' the great practical effect of which 

 is the sanctification of doubt; the recognition that 

 the profession of belief in propositions, of the truth 

 of which there is no sufficient evidence, is immoral; 

 the discrowning of authority as such; the repudia- 

 tion of the confusion, beloved of sophists of all 

 sorts, between free assent and mere piously gagged 

 dissent; and the admission of the obligation to 

 reconsider even one's axioms on due demand. 

 These, if I mistake not, are the notes of the 

 * Discours de la Methode. 1 Partie. 



