188 STUDY OF NATURAL HISTORY. 
CHAP. III. 
ON ARRANGEMENTS GENERALLY ; AND ON THOSE CON- 
SIDERATIONS WHICH SHOULD FORM THE . BASIS OF 
EVERY ATTEMPT TO CLASSIFY OBJECTS ACCORDING 
TO THE SYSTEM OF NATURE. 5 
(129.) THE innumerable objects composing the 
animal world, may be compared to the isolated facts 
of all physical sciences. For unless they are ar- 
ranged and digested under proper heads, no general 
conclusions from them can be drawn. No sooner, 
therefore, has the naturalist become acquainted 
with the forms of the objects he studies, than he 
proceeds to arrange them according to their agree- 
ments and disagreements. He first places them in 
primary groups, as an entomologist would separate 
the beetles from the butterflies ; and these, from the 
bees and the flies: from each of these, again, he 
proceeds to make other divisions; separating the 
butterflies which fly by day, from those which are 
nocturnal, and so on. ‘This is arrangement or 
classification ; from which all systems or methods 
originate. Now, it is obvious, that if we are not 
guided in this proceeding by some general rules 
known to be universally applicable, every one may 
consider himself qualified to follow his own im- 
pressions, and to make that arrangement which he 
thinks best. Hence have originated the innumer- 
