EXAMPLES OF THE FOUR METHODS. 809 



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 process altogether ; for what- 

 ever can not be reduced to syllogism, is not reasoning. And Dr. Whewell's 

 argument, if good at all, is good against all inferences from experience. In 

 saying that no discoveries were ever made by the Four Methods, he affirms 

 that none were ever made by observation and experiment ; for assuredly if 

 any were, it was by processes reducible to one or other of those methods. 



This difference between us accounts for the dissatisfaction which my ex- 

 amples give him ; for I did not select them with a view to satisfy any one 

 who required to be convinced that observation and experiment are modes 

 of acquiring knowledge : I confess that in the choice of them I thought 

 only of illustration, and of facilitating the conception of the Methods by 

 concrete instances. If it had been my object to justify the processes them- 

 selves as means of investigation, there would have been no need to look 

 far off, or make use of recondite or complicated instances. As a specimen 

 of a truth ascertained by the Method of Agreement, I might have chosen 

 the proposition, " Dogs bark." This dog, and that dog, and the other dog, 

 answer to A B C, A D E, A F G. The circumstance of being a dog an- 

 swers to A. Barking answers to a. As a truth made known by the Meth- 

 od of Difference, " Fire burns " might have sufficed. Before I touch the 

 fire I am not burned ; this is B C : I touch it, and am burned ; this is A B 

 C,aBC. 



Such familiar experimental processes are not regarded as inductions by 

 Dr. Whewell ; but they are perfectly homogeneous with those by which, 

 even on his own showing, the pyramid of science is supplied with its base. 

 In vain he attempts to escape from this conclusion by laying the most ar- 

 biti'ary restrictions on the choice of examples admissible as instances of 

 Induction : they must neither be such as are still matter of discussion 

 (p. 265), nor must any of them be drawn from mental and social subjects 

 (p. 269), nor fi'om ordinary observation and practical life (pp. 241-247). 

 They must be taken exclusively from the generalizations by which scientific 

 thinkers have ascended to great and comprehensive laws of natural phe- 

 nomena. Now it is seldom possible, in these complicated inquiries, to go 

 much beyond the initial steps, without calling in the instrument of Deduc- 

 tion, and the temporary aid of hypothesis; as I myself, in common with 

 Dr. Whewell, have maintained against the purely empirical school. Since, 

 therefore, such cases could not conveniently be selected to illustrate the 

 principles of mere observation and experiment, Dr. Whewell is misled by 

 their absence into representing the Experimental Methods as serving no 

 purpose in scientific investigation; forgetting that if those methods had 

 not supplied the first generalizations, there would have been no materials 

 for his own conception of Induction to work upon. 



His challenge, however, to point out which of the four methods are exem- 

 plified in certain important cases of scientific inquiry, is easily answered. 

 "The planetary paths," as far as they are a case of induction at all,* fall 

 under the Method of Agreement. The law of "falling bodies," namely, 

 that they describe spaces proportional to the squares of the times, was his- 



* See, on this point, the second chapter of the present book. 



