ROGER BACON. 81 



B. Next, we find Roger intimating that there are two 

 sorts of observations the one passive and vulgar, the other 

 active and learned. The latter alone deserves the name of 

 experiment : 



" There is," says he, " a natural and imperfect experiment 

 which is unconscious of its own power, which does not under- 

 stand its proceedings, and is in use among artisans, and not 

 among the learned. Over and above it, above all speculative 

 sciences and all arts, there is the art of making experiments 

 that are neither weak nor incomplete." But how will ex- 

 periments arrive at precise results ? By calculation, for 

 " Physicists must understand," says he, " that their science 

 is powerless, if they do not apply to it the power of mathe- 

 matics, without which observation languishes and is incapable 

 of certainty."* In Francis Bacon, again, we see the intimation 

 of the fact that observations are of two kinds; but he com- 

 pletely failed to grasp that which lies at the root of this 

 injunction the importance of calculation in scientific re- 

 searches and the absence of this requirement would by itself 

 suffice to vitiate his method and instruction even if these 

 were right in all other respects. The unfortunate fact that 

 he puts mathematics aside as an unworthy and deceptive 

 instrument proves his want of perception of the means and 

 ends of science. Roger, with masterful knowledge, sets forth 

 the foremost importance of mathematics with unerring force; 

 so that it is clear, as Lewes justly observes, that "after 

 having denounced the incompetence of the syllogistic method 

 of the schools, he endeavoured to substitute for it the 

 scientific method and its two handmaidens, mathematics and 

 experiment," thereby founding the Experimental School. 

 And Roger, lest he should seem faint-hearted, fears not to 

 reiterate his injunctions : " The exposition must be demon- 

 stration. That is impossible without experiment. We have 

 three means of knowledge authority, reasoning, experiment. 

 Authority has no value unless its reason be shown : it does 

 not teach ; it only calls for assent." 



At a time when authority was supreme and was accepted 

 as an article of faith, he had the courage to write in this 

 * Opus Majus, p. 199 (J ebb's Edition). 



G 



