300 OPERATIONS SUBSIDIARY TO INDUCTION. 



the greatest command over out knowledge already 

 acquired, and lead most directly to the acquisition of 

 more. The general problem of Classification, in refe- 

 rence to these purposes, may be stated as follows: To 

 provide that things shall be thought of in such groups, 

 and those groups in such an order, as will best 

 conduce to the remembrance and to the ascertainment 

 of their laws. 



Classification thus considered, differs from classi- 

 fication in the wider sense, in having reference to 

 real objects exclusively, and not to all that are ima- 

 ginable: its object being the due coordination in our 

 minds of those things only, with the properties of 

 which we have actually occasion to make ourselves 

 acquainted. But on the other hand it embraces all 

 really existing objects. We cannot constitute any one 

 class properly, except in reference to a general divi- 

 sion of the whole of nature ; we cannot determine the 

 group in which any one object can most conveniently 

 be placed, without taking into consideration all the 

 varieties of existing objects, all at least which have 

 any degree of affinity with it. No one family of 

 plants or animals could have been rationally consti- 

 tuted, except as part of a systematic arrangement of 

 all plants or animals; nor could such a general 

 arrangement have been properly made, without first 

 determining the exact place of plants and animals in a 

 general division of nature. 



The theory of scientific classification, in its most 

 general aspect, is now very well understood, owing 

 chiefly to the labours of the distinguished naturalists 

 to whom science is indebted for what are called 

 Natural Arrangements or Classifications, especially of 

 the organized world. Mr. Whewell, in his Philosophy 

 of the Inductive Sciences, has systematized a portion 



