

7 



relative to Blafcl^ Wattj fttf^ .Cavendish. 513 



inoculation, the probability that " he had discovered a safe- 

 guard " rose at once, by the force even of a single experi- 

 ment, to an amount which medical experience could " pre- 

 cisely " assign. 



Mr. Macauley considers the credulity of those whom he 

 calls " the dupes of Mesmerism," as due, not so much to 

 neglect of these laws of evidence, as to want of natural saga- 

 city ; but the history of science by no means justifies this view 

 of unfounded opinions : the truth is, that all sciences, except 

 the mathematical, had stood for centuries in the same posi- 

 tion in which such studies as go by the names of Animal Mag- 

 netism and Craniology, appear to stand now, — the position, 

 that is, of collections of alleged facts unscrutinized and un- 

 sifted, — of generalisations precariously deduced, and truths, 

 where they contained any, mystified and confused. 



This was the state of science when Bacon appeared. The 

 master science of evidence^ like every other science, requires 

 for its perfection both rules and examples. Bacon gave the 

 rules. It has been observed by one well-qualified to offer an 

 opinion, that " he traced not merely the outline but the rami- 

 jications of science that did not yet exist*." But the chief, 

 the all-pervading, ever-during benefit, — the force of direction, 

 which he gave to the progress of knowledge, consisted in this 

 — that he did " first analyse the inductive method correctly, 

 that he first taught the specific value of every part of its evi- 

 dence, and that with such precision," and such impressive - 

 ness, that a great school was founded upon his writings, who 

 have handed down from him the torch of science, and have 

 proceeded during the last two hundred years to practise, and 

 mature, his rules. 



Yet we shall do no more than describe a real change in the 

 history of inductive science, if we shall proceed to speak of the 

 experimental school of the aera which commences with Black 

 and Cavendish, as the school of Newton : for the severe reason 

 of the mathematician, grafted on that inductive principle of 

 simplifying, and hedging in, ideas more complex than space 

 and number, till they are divided and narrowed to the point 

 of demonstration, shone forth in Newton's immortal works, 

 and especially in his Optics, with a light as much more power- 

 ful than even the luminous lessons of Bacon, as example is 

 more powerful than precept. 



In this I believe you will agree with me, that if in our seats 

 of learning the attentive study of such examples of reasoning 

 had been made one of the essential requisites of an accom- 

 plished and sound education, we should not have seen so 

 * Playfair's Dissertation, Encycl. Brit., p. 55: 



