330 FALLACIES. 



rejecting or excluding, by negative instances, whatever is not 

 the forma or cause, in order to arrive at what is. But, that 

 this forma or cause is one thing, and that it is the same in all 

 hot objects, he has no more doubt of, than another person has 

 that there is always some cause or other. In the present state 

 of knowledge it could not be necessary, even if we had not 

 already treated so fully of the question, to point out how 

 widely this supposition is at variance with the truth. It is 

 particularly unfortunate for Bacon that, falling into this error, 

 he should have^fixed almost exclusively upon a class of inquiries 

 in which it was especially fatal; namely, inquiries into the 

 causes of the sensible qualities of objects. For his assumption, 

 groundless in every case, is false in a peculiar degree with 

 respect to those sensible qualities. In regard to scarcely any 

 of them has it been found possible to trace any unity of 

 cause, any set of conditions invariably accompanying the 

 quality. The conjunctions of such qualities with one another 

 constitute the variety of Kinds, in which, as already remarked, 

 it has not been found possible to trace any law. Bacon was 

 seeking for what did not exist. The phenomenon of which he 

 sought for the one cause has oftenestno cause at all, and when 

 it has, depends (as far as hitherto ascertained) on an unas 

 signable variety of distinct causes. 



And on this rock every one must split, who represents to 

 himself as the first and fundamental problem of science to 

 ascertain what is the cause of a given effect, rather than what 

 are the effects of a given cause. It was shown, in an early 

 stage of our inquiry into the nature of Induction,* how much 

 more ample are the resources which science commands for the 

 latter than for the former inquiry, since it is upon the latter 

 only that we can throw any direct light by means of experi 

 ment; the power of artificially producing an effect, implying 

 a previous knowledge of at least one of its causes. If we 

 discover the causes of effects, it is generally by having pre 

 viously discovered the effects of causes : the greatest skill in 

 devising crucial instances for the former purpose may only 



* Supra, book iii. ch. vii. 4. 



