DISCOURSE ON METHOD. 8 1 



thereto no explication of any new- matter that it may 

 not be necessary to pass without end from one thing 

 to another. 



If some of the matters of which I have spoken in 

 the beginning of the Dioptrics and Meteorics should 

 offend at first sight, because I call them hypotheses 

 and seem indifferent about giving proof of them, I 

 request a patient and attentive reading of the whole, 

 from which I hope those hesitating will derive satis- 

 faction ; for it appears to me that the reasonings are 

 so mutually connected in these Treatises, that, as 

 the last are demonstrated by the first which are 

 their causes, the first are in their turn demonstrated 

 by the last which are their effects. Nor must it be 

 imagined that I here commit the fallacy which the 

 logicians call a circle ; for since experience renders 

 the majority of these effects most certain, the causes 

 from which I deduce them do not serve so much to 

 establish their reality as to explain their existence ; 

 but on the contrary, the reality of the causes is 

 established by the reality of the effects. Nor have 

 I called them hypotheses with any other end in view 

 except that it may be known that I think I am able 

 to deduce them from those first truths which I have 

 already expounded ; and yet that I have expressly 

 determined not to do so, to prevent a certain class 

 of minds from thence taking occasion to build some 

 extravagant Philosophy upon what they may take to 

 be my principles, and my being blamed for it. I 

 refer to those who imagine that they can master in a 

 day all [ that another has taken twenty years to 

 think out, as soon as he has spoken two or three 



