PRINCIPLE OF VARIATION. 131 



to all known animals? In proportion as we can de- 

 monstrate the extent of the theory by which we propose 

 to answer these questions, so do we approach the de- 

 velopement of the natural system, and reduce the ele- 

 ments of science to their most simple definitions. 

 Finally, it results from these considerations that a theory 

 which embraces them all will exhibit a unity of plan 

 which cannot possibly be the result of human ingenuity, 

 and which will, consequently, be the nearest approach 

 to that which must ever distinguish the natural system. 

 Such are the obvious considerations by which we are to 

 be guided in judging the merits of any classification, 

 which professes to be according to nature. In describing 

 theoretically what should constitute the developement of 

 the natural system, we have only alluded to those cir- 

 cumstances which have already been partially developed, 

 or which have been admitted as highly probable by 

 others, who have, nevertheless, declared their inability 

 to reconcile them with observed facts. 



(183.) Of natural systems, strictly speaking, there 

 cannot, as we have already seen, be more than one; 

 but it is equally clear, that, if we confine this title to that 

 one only which makes the nearest approach to nature, 

 and which gives the fullest explanation of the pheno- 

 mena she exhibits, we must term all other systems 

 artificial, and thus confound, under one name, two de- 

 scriptions of arrangements, which are grounded on to- 

 tally different principles. In order, therefore, to mark 

 their distinction with still greater precision, we shall 

 consider all those systems to be artificial which are not 

 grounded on any universal principles of arrangement; 

 which exhibit the animal series without plan or harmo- 

 nious connection, and which disregard analogies and 

 affinities. On the other hand, we shall consider those 

 as natural systems which involve any one or more of 

 these considerations, and which, looking beyond the in- 

 dividual, attempt to ascertain its station in the scale of 

 being, by pointing out the various relations which it 

 respectively holds with other objects. From this view 

 K 2 



