134 THE PRINCIPLES OF SCIENCE. 



regretted that no distinct theory of the constitution of 

 comets had guided his observations of Halley's comet a ; in 

 attempting to verify or refute any good hypothesis, not 

 only would there have been a chance of establishing a true 

 theory, but if confuted, the very confutation would pro- 

 bably have involved a large store of useful observations. 



It would be an interesting work, but one which I can- 

 not undertake, to trace out the gradual reaction which has 

 taken place in recent times against the purely empirical, 

 or Baconian, theory of induction. Francis Bacon, seeing 

 the futility of the scholastic logic, which had long been 

 predominant, asserted that the accumulation of facts and 

 the careful and orderly abstraction of axioms, or general 

 laws from them, constituted the true method of induction. 

 This method, as far as we can gather its exact nature 

 from Bacon's writings, would correspond to the -process of 

 exhaustive examination and classification to which I 

 have just alluded. The value of this method might 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, his successors, 

 we find that discovery was achieved by the exactly 

 opposite method to that advocated by Bacon. Through- 

 out Newton's works, as I shall more fully show in suc- 

 ceeding pages, we find deductive reasoning wholly pre- 

 dominant, and experiments are employed, as they should 

 be, to confirm or refute hypothetical 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 



a Tyndall, 'On Cometary Theory,' Philosophical Magazine, April, 

 1869. 4th Series, vol. xxxvii. p. 243. 



