MEMOIR OF ARISTOTLE. 
103 
enemies, and explains the ordinary means by which 
each class provides for its preservation and defence. 
In taking this w'ide survey of animated nature, 
Aristotle pretends not to exhaust its infinitely va- 
ried branches, for these defy the grasp of science ; 
but in the multitude of important and well as- 
certained facts which he relates, and which is in- 
comparably greater than will be found in any work 
of equal compass, it is his main purpose to illustrate 
the general heads above mentioned, and to expound 
the properties or affections common to the greatest 
or most distinguished portion of the whole animal 
kingdom. To these general heads or common pro- 
perties, he constantly has respect in the historical 
part of the work ; so that his minutest observations 
respecting the humblest and least perfectly organized 
animal are often found to elucidate or confirm some 
important law of the animal economy *. His sys- 
tem, inasmuch as the range of his observation was 
limited, was necessarily defective. The world created 
by the microscope had not any existence for the phi- 
losophers of antiquity. By means of this and other 
inventions, the chain of being has been extended far 
beyond what the unassisted eye could possibly have 
reached. Our wider acquaintance with the different 
regions of the globe, has increased our knowledge 
of the animal kingdom ; and our superiority in ex- 
perimental science has thrown new light on the struc- 
ture and functions of the animal economy. The ap- 
■ Gillies’s New Analysis of Aristotle’s Works, vol. i. 
p. 146. 
