124' ON SYSTEMATIC ZOOLOGY. 



groups (that is to say, groups which the judgment im- 

 mediately pronounces as not to be those of nature), while, 

 in other respects, it may preserve the natural series. If, 

 therefore, we were to rest content with this difference 

 between a natural and an artificial system, we should 

 have a difference without a distinction ; both might be 

 called natural, and both artificial ; the difference would 

 only be in degree; and that degree would rest upon 

 individual opinion, because, where there are no fixed 

 principles by which the judgment in such matters is to 

 be regulated, there could be no unanimity of opinion. 

 Besides, it would inevitably follow, that our application 

 of these terms to any given system would be subject to 

 change. A system, which we would term natural in 

 one state of the science, would be artificial in another ; 

 so soon as it was supplanted by more recent discoveries, 

 and a more harmonious combination of objects. We 

 must search, therefore, for a clearer definition of these 

 two modes of arrangement. 



(177-) Much metaphysical discussion has arisen on 

 the difference between natural and artificial systems, 

 which has left the subject pretty nearly in the same un- 

 decided state, while some of these discussions have rather 

 increased than dissipated the obscurity in which it has 

 been involved. Some maintain, that, as all systems 

 hitherto promulgated are more or less defective, and 

 have failed to reconcile and explain all the intricacies 

 of the natural series, therefore, they argue, all systems 

 are, and must be, artificial. Mr. MacLeay, in his con- 

 troversy with Mr. Bicheno * on systems and methods, 

 evidently embraces this view of the subject, and his 

 opinion has been more recently taken up by one of his 

 disciples. He asks : " Pray let me know where I shall 

 find one of these natural systems, and I shall be con- 

 tent." Again : " Naturalists have been looking for 

 one natural system, only one; and, confined as their aim 

 is, they have not as yet been able to attain it ? "t What 



* Zool. Journ. vol iv. p. 409. + Ibid. p. '410. 



