PUBLISHERS' PREFACE. 



DESCARTES' Discourse on Method was published in Leyden, 

 in 1637, and was accompanied by three brief tracts as appendices : 

 the^ Geometry, the Meteorics, and the Dioptrics. 



The Discourse on Method was Descartes' intellectual confes- 

 sion of faith, his statement of his own peculiar method of reaching 

 the Truth ; the appendices were his documents of justification, 

 specimens of the actual Truth that he had reached by his method. 

 And splendid specimens they were : the invention of analytical 

 geometry, which literally unshackeled mathematical research ; the 

 researches in the theory of equations and algebraical symbolism ; 

 the enunciation of the law of the refraction of light, which is the 

 beginning of the development of modern optics ; the partial ex- 

 planation of the rainbow ; and so forth. All these achievements, 

 far as they may seem from the common life, are shot througn the 

 warp and woof of our technical civilisation, and our entire spiritual 

 and material existence bears their hidden impress. 



Whether our calling, therefore, be that of a philosopher or 

 not, and whatever be our attitude to the problems involved, the 

 contemplation of the methods by which such unique results have 

 been reached is of the highest concern. No one can fail to draw 

 a most bountiful stimulus from these pages. Their freshness 

 and independence of view, their wholesome common sense, their 

 self-reliance, their apotheosis of Reason, are, when we consider 

 the state of mind of thej>eriod in which they were written, almost 

 unequalled in history. Here was an absolute break with the 

 authority of tradition, an utter rejection of the past, an utter con- 

 tempt of books, of the graces of literature and of erudition ; while 

 in their place were substituted the ideals of radical doubt, impla- 

 cable critique, unerring certainty. Truth was no longer a "plural- 

 ity of suffrages," the utterance of an Aristotle or a Pope ; it was 



