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NOMENCLATURE AND CLASSIFICATION. 15 
CHAPTERII. 
NOMENCLATURE AND CLASSIFICATION. 
PROCEEDING upon the view that there is a close 
analogy between the way in which every individ- 
ual student penetrates into Nature and the pro- 
gress of science as a whole in the history of hu- 
manity, I continue my sketch of the successive 
steps that have led to our present state of knowl- 
edge. I began with Aristotle, and showed that 
this great philosopher, though he prepared a 
digest of all the knowledge belonging to his 
time, yet did not feel the necessity: of any sys- 
tem or of any scientific language differing from 
the common mode of expression of his day. He 
presents his information.as a man with his eyes 
open narrates in a familiar style what he sees. 
As civilization spread-and science had its repre- 
sentatives in other countries besides Greece, it 
became indispensable to have a common scien- 
tific language, a technical nomenclature, combin- 
ing many objects under common names, and 
enabling every naturalist to express the results 
of his observations readily and simply in a man- 
