EXAMPLES OF THE FOUR METHODS. 



There is a striking similarity between the objections here 

 made against Canons of Induction, and what was alleged, in 

 the last century, by as able men as Dr. Whewell, against the 

 acknowledged Canon of Eatiocination. Those who protested 

 against the Aristotelian Logic said of the Syllogism, what 

 Dr. Whewell says of the Inductive Methods, that it &quot; takes 

 for granted the very thing which is most difficult to discover, 

 the reduction of the argument to formula such as are here 

 presented to us.&quot; The grand difficulty, they said, is to obtain 

 your syllogism, not to judge of its correctness when obtained. 

 On the matter of fact, both they and Dr. Whewell are right. 

 The greatest difficulty in both cases is first that of obtaining 

 the evidence, and next, of reducing it to the form which tests 

 its conclusiveness. But if we try to reduce it without know 

 ing to what, we are not likely to make much progress. It is 

 a more difficult thing to solve a geometrical problem, than to 

 judge whether a proposed solution is correct: but if people 

 were not able to judge of the solution when found, they would 

 have little chance of finding it. And it cannot be pretended 

 that to judge of an induction when found, is perfectly easy, is 

 a thing for which aids and instruments are superfluous ; for 

 erroneous inductions, false inferences from experience, are quite 

 as common, on some subjects much commoner, than true ones. 

 The business of Inductive Logic is to provide rules and models 

 (such as the Syllogism and its rules are for ratiocination) to 

 which if inductive arguments conform, those arguments are 

 conclusive, and not otherwise. This is what the Four 

 Methods profess to be, and what I believe they are universally 

 considered to be by experimental philosophers, who had prac 

 tised all of them long before any one sought to reduce the 

 practice to theory. 



The assailants of the Syllogism had also anticipated Dr. 

 Whewell in the other branch of his argument. They said 

 that no discoveries were ever made by syllogism ; and Dr. 

 Whewell says, or seems to say, that none were ever made by 

 the four Methods of Induction. To the former objectors, 

 Archbishop Whately very pertinently answered, that their 

 argument, if good at all, was good against the reasoning pro- 



