224 THE PRINCIPLES OF SCIENCE. 



to consider by what logical procedure he attains the 

 truth. 



If I have taken a correct view of logical method, there 

 is really no such thing as a distinct process of induction. 

 The probability is infinitely small that a collection of 

 complicated facts will fall into an arrangement capable 

 of exhibiting directly the laws obeyed by them. The 

 mathematician might as well expect to integrate his 

 functions by a ballot-box, as the experimentalist to draw 

 deep truths from haphazard trials. All induction is but 

 the inverse application of deduction, and it is by the 

 inexplicable mental action of a gifted mind that a multi- 

 tude of heterogeneous facts are caused to range them- 

 selves in luminous order as the results of some uniformly 

 acting law. So different, indeed, are the qualities of mind 

 required in different branches of science that it would 

 be absurd to attempt to give an exhaustive description 

 of the character of mind which leads to discovery. The 

 labours of Newton could not have been accomplished 

 except by a mind of the utmost mathematical genius ; 

 Faraday, on the other hand, has made the most extensive 

 and undoubted additions to human knowledge without 

 ever passing beyond common arithmetic. I do not re- 

 member meeting in Faraday's writings with a single 

 algebraic formula or mathematical problem of any com- 

 plexity. Professor Clerk Maxwell, indeed, in the preface 

 to his new ' Treatise on Electricity,' has strongly re- 

 commended the reading of Faraday's researches by all 

 students of science, and has given his opinion that though 

 Faraday seldom or never employed mathematical formulae, 

 his methods and conceptions were not the less mathe- 

 matical in their nature b . I have myself protested against 

 the prevailing confusion between a mathematical and an 



b See also ' Nature/ Sept. 18, 1873 ; vol. viii. p. 398. 



