368 INDUCTION. 



can not itself be reduced to any law. There is, as formerly remarked,* no 

 uniformity, no norma, principle, or rule, perceivable in the distribution of 

 the primeval natural agents through the universe. The different substances 

 composing the earth, the powers that pervade the universe, stand in no con- 

 stant relation to one another. One substance is more abundant than oth- 

 ers, one power acts through a larger extent of space than others, with- 

 out any pervading analogy that we can discover. We not only do not 

 know of any reason why the sun's attraction and the force in the direc- 

 tion of the tangent co-exist in the exact proportion they do, but we can trace 

 no coincidence between it and the proportions in which any other element- 

 ary powers in the universe are intermingled. The utmost disorder is ap- 

 parent in the combination of the causes, which is consistent with the most 

 regular order in their effects ; for when each agent carries on its own op- 

 erations according to a uniform law, even the most capricious combination 

 of agencies will generate a regularity of some sort ; as we see in the kalei- 

 doscope, where any casual arrangement of colored bits of glass produces 

 by the laws of reflection a beautiful regularity in the effect. 



§ 4. In the above considerations lies the justification of the limited degree of 

 reliance which scientific inquirers are accustomed to place in empirical laws. 



A derivative law which results wholly from the operation of some one 

 cause, will be as universally true as the laws of the cause itself ; that is, 

 it will always be true except where some one of those effects of the cause, 

 on which the derivative law depends, is defeated by a counteracting cause. 

 But when the derivative law results not from different effects of one cause, 

 but from effects of several causes, we can not be certain that it will be true 

 under any variation in the mode of co-existence of those causes, or of the 

 primitive natural agents on which the causes ultimately depend. The 

 proposition that coal-beds rest on certain descriptions of strata exclusively, 

 though true on the earth, so far as our observation has reached, can not be 

 extended to the moon or the other planets, supposing coal to exist there ; 

 because we can not be assured that the original constitution of any other 

 planet was such as to produce the different depositions in the same order 

 as in our globe. The derivative law in this case depends not solely on 

 laws, but on a collocation ; and collocations can not be reduced to any law. 



Now it is the very nature of a derivative law which has not yet been re- 

 solved into its elements, in other words, an empirical law, that we do not 

 know whether it results from the different effects of one cause, or from ef- 

 fects of different causes. We can not tell whether it depends wholly on 

 laws, or partly on laws and partly on a collocation. If it depends on a 

 collocation, it will be true in all the cases in which that particular colloca- 

 tion exists. But, since we are entirely ignorant, in case of its depending 

 on a collocation, what the collocation is, we are not safe in extending the 

 law beyond the limits of time and place in which we have actual experience 

 of its truth. Since within those limits the law has always been found 

 true, we have evidence that the collocations, whatever they are, on which 

 it depends, do really exist within those limits. But, knowing of no rule or 

 principle to which the collocations themselves conform, we can not con- 

 clude that because a collocation is proved to exist within certain limits of 

 place or time, it will exist beyond those limits. Empirical laws, therefore, 

 can only be received as true within the limits of time and place in which 



* Supra, book iii., chap, v., § 7. 



