EXPLANATION OF LAWS. ^73 



A produces B. It is- also less general than the law that B produces . 

 C. For B may h^vc other causes besides A ; and as A produces C 

 only by means of B, while B produces C whether it has itself been 

 prpduced by A or by anything else, tlie second law embraces a greater 

 number of -instances, covers as.it were a greater space of ground, than 

 the first 



Thus,- in our former cxami^lc, the ]aw that the contact- of an object 

 causes a change in the state of the nerve, is more general than the 

 law that contact with an object causes sensation, siuce, for aught we 

 know^the change in- the nerve may equally take place when, from 

 a counteracting cause, as for instance strong jneutal excitement, the 

 sensation docs not follow ; as in a battle, where woun,ds are often re- 

 ceived without any ctmsciousness of receiving them. And again, the 

 law tliat change in the state of a nein-e produces sensation, is more 

 general than the law that contact with an object produces sensation ; 

 since the sensation equally follows the change in the nerve when nxjt 

 produced by contact with an object, but by some othet cause; as in 

 the well kno>vTi case, when a person who has lost a limb feels the vevj 

 sensation which he lias been accustomed to Call a pain in the limb. . 



Not only are the laws of more immediate sequence into which the 

 law of a remote se(]uencc is resolved, laws of greater generality than 

 that law is, but (as a' consequence of, or rather a^ implied hi, .thei:t: 

 greater generality,) they are more to bq relied ob ; tliere are fewer 

 chances of their being ultimately found not to be universally true. 

 From the moment when the sequence of A and C is i^hown not to be. 

 immediate, but to depend upon an intervening phenomenon, then, how- 

 ever constant and invariable the sequence of A and C has hitherto been 

 found, possibilities arise of its failure, exceeding those which can affect 

 either of the more immediate sequences, A B and BC. The tendency 

 of A to produce C may be defeated by Avhatevcr is capable of defeat- 

 iT\g either the teVidency of A to produce B, or the tendency of B to 

 produce C ; it is therefore twice as liable to failure as either of those 

 rnore elementary tendencies ; and the generalizatioji that A j& always 

 followed by C; is twice as likely to be found erroneous. And so of the 

 converse generalization, that C is always preceded and caused by A; 

 which will be erroneous not only if there should happen to be a second 

 immediate mode of production of C itself, but moreover if there be a 

 second mode of production pfB, the^mmediate, antocedent of C- in the- 

 sequencc/ , ...."■ 



The resolutipn of the. one generalization into, the ■ other two, not 

 only shows that there are possible limitations- of the former, from 

 which its two elements are exempt, but shows also where these are to 

 be looked for. Assoon as we know that B intervenes between A and 

 C, we also know that if there be cases in which the sequence of A 

 and C does not hold, these are most likely to be found by studying the 

 effects and the conditions of the phenomenon B. 



It appears, then, that in the second of the three modes in which a 

 law may be resolved into other laws, the latter are more; general, that 

 is, extend to more cases, and are also less likely to retpiire limitation 

 from subsequent experience, than the law which they serve U) explain. 

 They are more nearly unconditional ; tlu^y are defeated by fewer con- 

 tingencies ; they are a nearer approach to the universal truth of nature. 

 The same obsen-ations are still more evidently true with regard to the 



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