178 A Short History of Astronomy [CH. vi., $ i 34 



Galilei's own statement of it, as applied to a particular 

 case: 



"Let us therefore take this at present as a Postulatum, the 

 truth whereof we shall afterwards find established, when we 

 shall see other conclusions built upon this Hypothesis, to answer 

 and most exactly to agree with Experience.'' * 



* Two New Sciences, translated by Western, p. 255. 



