xxiii.] THE USE OF HYPOTHESIS. 507 



and exhaustively classifying them, to which I alluded. 

 The value of this method may be estimated historically 

 by the fact that it has not been followed by any of 

 the great masters of science. Whether we look to Galileo 

 who preceded Bacon, to Gilbert, his contemporary, or 

 to Newton and Descartes, Leibnitz and Huyghens, his 

 successors, we find that discovery was achieved by the 

 opposite method to that advocated by Bacon. Through- 

 out Newton's works, as I shall show, we find deductive 

 reasoning wholly predominant, and experiments are em- 

 ployed, as they should be, to confirm or refute hypothe- 

 tical anticipations of nature. In my " Elementary Lessons 

 in Logic" (p. 258), I stated my belief that there was no 

 kind of reference to Bacon in Newton's works. I have 

 since found that Newton does once or twice employ the 

 expression experimentum crucis in his " Opticks," but this 

 is the only expression, so far as I am aware, which could 

 indicate on the part of Newton direct or indirect ac- 

 quaintance with Bacon's writings. 1 



Other great physicists of the same age were equally 

 prone to the use of hypotheses rather than the blind 

 accumulation of facts in the Baconian manner. Hooke 

 emphatically asserts in his posthumous work on Philo- 

 sophical Method, that the first requisite of the Natural 

 Philosopher is readiness at guessing the solution of pheno- 

 mena and making queries. " He ought to be very well 

 skilled in those several kinds of philosophy already 

 known, to understand their several hypotheses, sup- 

 positions, collections, observations, &c., their various ways 

 of ratiocinations and proceedings, the several failings and 

 defects, both in their way of raising and in their way of 

 managing their several theories: for by this means the 

 mind will be somewhat more ready at guessing at the 

 solution of many phenomena almost at first sight, and 

 thereby be much more .prompt at making queries, and at . 

 tracing the subtlety of Nature, and in discovering and 

 searching into the true reason of things." 



We find Horrocks, again, than whom no one was more 



1 See Philosophical Transactions, abridged by Lowthorp. 4th edit, 

 vol. i. p. 130. I find that opinions similar to those in the text have 

 been briefly expressed by De Morgan in his remarkable preface to 

 From Matter to Spirit, by C.D., pp. xxi. xxii. 



