86 STUDY OF NATURAL HISTORY. 
introduced a precision it had never before possessed. . 
His object was to make known every natural pro- 
duction there discovered, in the most simple and 
concise terms; and to institute rules and forms of 
description, by which other objects, as they were 
progressively discovered, might be distinguished 
and registered in the same manner. In this he 
succeeded more completely than any who had 
then, or who has since, undertaken the same task. 
Unlike his great successor Cuvier, he knew the 
difference between a natural and an artificial system ; 
he appreciated the value of the former, but he pro- 
secuted his invention of the latter, because he saw 
it was more suited to the then state of science. 
That he possessed no inconsiderable knowledge of 
comparative anatomy, is abundantly evident; but he 
knew that the external characters of most animals 
were quite sufficient for the purpose of identifying 
them: and he wisely refrained from overburdening 
his definitions with unessential details and characters, 
Simplicity, in short, was his ruling passion, and it 
would be well for modern science if this principle 
had been imbibed by his successors. That he was 
ever anxious to improve his classification, to institute 
new divisions, modify his old genera, and make new 
ones, is attested by every succeeding edition of his 
Systema Nature, which he went on to improve until 
his death. These augmentations, however, were 
almost solely the result of personal knowledge. He 
possessed the spirit, the judgment, and the caution of 
Willughby, in rejecting all the vague and ill-defined 
species both of plants and of animals, mentioned 
by other writers and thus purged the science of a 
