30 PREFACE. 



both) two sources, and two distributions of learning, and 

 in like manner two tribes, and as it were kindred families 

 of contemplators or philosophers, without any hostility or 

 alienation between them ; but rather allied and united by 

 mutual assistance. Let there be in short one method of 

 cultivating the sciences, and another of discovering them. 

 And as for those who prefer and more readily receive the 

 former, on account of their haste or from motives arising 

 from their ordinary life, or because they are unable from 

 weakness of mind to comprehend and embrace the other 

 (which must necessarily be the case with by far the greater 

 number), let us wish that they may prosper as they desire 

 in their undertaking, and attain what they pursue. But 

 if any individual desire and is anxious not merely to adhere 

 to and make use of present discoveries, but to penetrate still 

 further, and not to overcome his adversaries in disputes but 

 nature by labour, not in short to give elegant and specious 

 opinions, but to know to a certainty and demonstration, let 

 him, as a true son of science (if such be his wish), join 

 with us ; that when he has left the antichambers of nature 

 trodden by the multitude, an entrance may at last be dis 

 covered to her inner apartments. And in order to be 

 better understood, and to render our meaning more fami 

 liar by assigning determinate names, we have accustomed 

 ourselves to call the one method the anticipation of the 

 mind, and the other the interpretation of nature. 



We have still one request left. We have at least re 

 flected and taken pains in order to render our propositions 

 not only true, but of easy and familiar access to men s 

 minds, however wonderfully prepossessed and limited. Yet 

 it is but just that we should obtain this favor from man 

 kind (especially in so great a restoration of learning and 

 the sciences), that whosoever may be desirous of forming 

 any determination upon an opinion of this our work either 

 from his own perceptions, or the crowd of authorities, or 

 the forms of demonstrations, he will not expect to be able 

 to do so in a cursory manner, and whilst attending to other 

 matters; but in order to have a thorough knowledge of 

 the subject, will himself by degrees attempt the course 

 which we describe and maintain; will become accustomed 

 to the subtilty of things which is manifested by experi 

 ence ; and will correct the depraved and deeply rooted 

 habits of his mind by a seasonable and as it were just hesi 

 tation : and then finally (if he will) use his judgment when 

 he has begun to be master of himself. . 



