EXPLANATION OF LAWS. 521 



C, is less general than either of the laws which connect B 

 with C and A with B. This will appear from very simple 

 considerations. 



All laws of causation are liable to be counteracted or frus 

 trated, by the non-fulfilment of some negative condition : the 

 tendency, therefore, of B to produce C may be defeated. Now 

 the law that A produces B, is equally fulfilled whether B is 

 followed by C or not ; but the law that A produces C by 

 means of B, is of course only fulfilled when B is really followed 

 by C, and is therefore less general than the law that A pro 

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

 0. For B may have other causes besides A ; and as A pro 

 duces only by means of B, while B produces C whether it 

 has itself been produced by A or by anything else, the second 

 law embraces a greater number of instances, covers as it were 

 a greater space of ground, than the first. 



Thus, in our former example, the law 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 sensa 

 tion, since, for aught we know, the change in the nerve may 

 equally take place when, from a counteracting cause, as for 

 instance, strong mental excitement, the sensation does not 

 follow ; as in a battle, where wounds are sometimes received 

 without any consciousness of receiving them. And again, the 

 law that change in the state of a nerve produces sensation, is 

 more general than the law that contact with an object pro 

 duces sensation ; since the sensation equally follows the change 

 in the nerve when not produced by contact with an object, 

 but by some other cause ; as in the well-known case, when a 

 person who has lost a limb, feels the same sensation which he 

 has 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 sequence is resolved, laws of greater 

 generality than that law is, but (as a consequence of, or rather 

 as implied in, their greater generality) they are more to be 

 relied on ; there are fewer chances of their being ultimately 

 found not to be universally true. From the moment when 

 the sequence of A and C is shown not to be immediate, but to 



