eo 
VI 
A ORITICAL EXAMINATION OF THE POSITION OF 
MR. DARWIN'S WORK, “ON THE ORIGIN OF 
SPECIES,” IN RELATION TO THE COMPLETE 
THEORY OF THE CAUSES OF THE PHENOMENA 
OF ORGANIC NATURE. 
In the preceding five lectures I have endeavy- 
oured to give you an account of those facts, and 
of those reasonings from facts, which form the 
data upon which all theories regarding the causes 
of the phenomena of organic nature must be 
based. And, although I have had frequent 
occasion to quote Mr. Darwin—as all persons here- 
after, in speaking upon these subjects, will have 
occasion to quote his famous book on the “ Origin 
of Species,’—you must yet remember that, wher- 
ever I have quoted him, it has not been upon 
theoretical points, or for statements in any way 
connected with his particular speculations, but on 
matters of fact, brought forward by himself, or 
collected by himself, and which appear incidentally 
in his book, If a man will make a book, pro- 
