CHAPTER V. 



ON THE TRUE ARRANGEMENT AND CLASSIFICATION OF ANIMALS. 



For the progress of zoological philosophy and the object that we have 

 in view, it is necessary to enquire into the true arrangement and 

 classification of animals ; to consider how such an arrangement 

 came about ; to ascertain what principles should be observed in set- 

 ting up that general arrangement ; and, finally, to investigate what 

 remains to be done in order to bring that arrangement into the closest 

 harmony with the actual order of nature. 



But in order that our studies may be profitable, we must first deter- 

 mine the essential aims of an arrangement and of a classification of 

 animals ; for these two aims are very different in nature. 



The aim of a general arrangement of animals is not only to possess 

 a convenient list for consulting, but it is more particularly to have an 

 order in that Ust which represents as nearly as possible the actual 

 order followed by nature in the production of animals ; an order con- 

 spicuously indicated by the afl&nities which she has set between them. 



The aim of a classification of animals, on the other hand, is to furnish 

 points of rest for our imagination, by means of lines of demarcation 

 drawn at intervals in the general series ; so that we may be able 

 more easily to identify each race already discovered, to grasp its 

 affinities with other known animals, and to place newly discovered 

 species in their proper position. This device makes up for our own 

 shortcomings, facilitates our studies and our knowledge, and is 

 absolutely necessary for us ; but I have already shown that it is a 

 produce of artifice, and that despite appearances it corresponds to 

 nothing real in nature. 



An accurate determination of afiinities between objects will always 

 begin by fixing in our general arrangements the place of the large 

 groups or primary divisions ; then that of the lesser groups, and lastly 

 that of the species or special races that have been observed. Now 

 here is the inestimable advantage accruing to science from a know- 



