INDUCTION IN ITS VARIOUS SENSES 37 



astronomy. Indeed the superior powers of Aristotle, and of his mediaeval 

 Christian commentators, in the domain of ordinary, unaided observation, are 

 undisputed at the present day. But it would be wrong to arrogate to them 

 an honour they would be themselves the first to disclaim, the honour of creat 

 ing sciences which could not possibly have arisen without the invention of the 

 special instruments of observation and measurement just referred to. 



Accurate experimentation was impossible in the Middle Ages, in the 

 absence of those delicate means of weighing and measuring that are the inven 

 tion of a more modern era. The thirteenth century, however, the golden age 

 of Scholasticism produced at least one exceptional and extraordinary man, 

 whose name cannot be passed over in connexion with the rise of scientific in 

 duction. Roger Bacon, a Franciscan monk, who lived through the greater 

 part of that century, dying at Oxford in 1 294, rose far above the commonplaces 

 of his time in his advocacy of the experimental method. His life was one im 

 passioned and even fanatical plea for the positive sciences. Nor did he con 

 tent himself with pleading : he set an example by devoting his great genius to 

 conducting scientific experiments and inventing instruments for that purpose. 



He distinguished four possible ways of gaining a knowledge of nature : 

 authority, (a priori) reasoning, observation, and experiment. And he tells us 

 that of these four the first ranks lowest in worth : &quot; auctoritas debilior est 

 ratione &quot; ; the second, dialectic reasoning, does not satisfy the mind : &quot; non 

 certificat &quot; ; nor the third, which is ordinary, superficial observation. The 

 fourth alone &quot; internal &quot; or &quot; intrinsic &quot; experience is convincing, and that 

 owing to the aid it receives from mathematics and geometry. He anticipated 

 more renowned and more modern philosophers in an attempt to establish one 

 general science that would submit to mathematical principles all the varied 

 interactions of the bodies that make up the physical universe. 1 



209. LORD BACON S &quot; NOVUM ORGANON&quot;: THE Two 

 IDEALS OF GENERALIZATION. The English monk of the thir 

 teenth century understood the nature and method of experimental 

 science as well as, if not better than, his namesake of the six 

 teenth. Francis Bacon, Lord Verulam (1561-1626), is commonly 

 regarded as the &quot; founder of the inductive method &quot;. Wrongly, 

 however ; because, in the first place, his method of &quot; interpreting 

 nature &quot; has never been adopted : &quot; The value of this method,&quot; 

 writes Jevons, 2 &quot; may be estimated historically by the fact that 

 it has not been followed by any of the great masters of science.&quot; 



Bacon blamed his predecessors, the &quot; deductive &quot; philosophers, 

 for &quot;anticipating&quot; nature instead of &quot; interpreting &quot; it. After 

 enumerating four great sources of such fallacious &quot; anticipations &quot; 

 the &quot; Idola &quot; or Phantoms : (a) of the Tribe (common to all men), 

 (fr) of the Cave (due to personal idiosyncrasies), (c] of the Market- 



1 Op. maj., p. iv., dist. i., c. iii., dist. ii.-iv. ; Opus tertium, c. 29-37, etc. ; cf. 

 DELORME, Dictionnaire de theologie catholique, s.v. Bacon, 



2 Principles of Science, p. 507. 



