24 INDUCTION. 



extend still further. But that, in doing this, we should 

 imagine ourselves to be seriously inquiring whether the 

 hypothesis of an ether, an electric fluid, or the like, is true ; 

 that we should fancy it possible to obtain the assurance 

 that the phenomena are produced in that way and no other ; 

 seems to me, I confess, unworthy of the present improved 

 conceptions of the methods of physical science.. And at the 

 risk of being charged with want of modesty, I cannot help 

 expressing astonishment that a philosopher of Dr. Whewell s 

 abilities and attainments should have written an elaborate 

 treatise on the philosophy of induction, in which he recog 

 nises absolutely no mode of induction except that of trying 

 hypothesis after hypothesis until one is found which fits the 

 phenomena ; which one, when found, is to be assumed as true, 

 with no other reservation than that if on re-examination it 

 should appear to assume more than is needful for explaining 

 the phenomena, the superfluous part of the assumption 

 should be cut off. And this without the slightest distinc 

 tion between the cases in which it may be known beforehand 

 that two different hypotheses cannot lead to the same result, 

 and those in which, for aught we can ever know, the range of 

 suppositions, all equally consistent with the phenomena, may 

 be infinite.* 



* In Dr. Whewell s latest version of his theory (Philosophy of Discovery, 

 p. 331) he makes a concession respecting the medium of the transmission of 

 light, which, taken in conjunction with the rest of his doctrine on the subject, 

 is not, I confess, very intelligible to me, but which goes far towards removing, 

 if it does not actually remove, the whole of the difference between us. He is 

 contending, against Sir William Hamilton, that all matter has weight. Sir 

 William, in proof of the contrary, cited the luminiferous ether, and the calorific 

 and electric fluids, which, &quot; he said, &quot;we can neither denude of their character 

 of substance, nor clothe with the attribute of weight.&quot; &quot; To which,&quot; continues 

 Dr. Whewell, &quot;my reply is, that precisely because I cannot clothe these agents 

 with the attribute of Weight, I do denude them of the character of Substance. 

 They are not substances, but agencies. These Imponderable Agents, are not pro 

 perly called Imponderable Fluids. This I conceive that I have proved.&quot; Nothing 

 can be more philosophical. But if the luminiferous ether is not matter, and 

 fluid matter too, what is the meaning of its undulations ? Can an agency undu 

 late ? Can there be alternate motion forward and backward of the particles of 

 an agency ? And does not the whole mathematical theory of the undulations 

 imply them to be material ? la it not a series of deductions from the known 



