170 Review of Darwin’s Theory on the Origin of Species. 
The gist of Mr. Darwin’s work is to show that such varieties 
are gradually diverged into species and genera through natuml 
selecuon ; that natural selection is the inevitable result of 
struggle for existence which all living things are engaged in; and 
that this struggle is an unavoidable consequence of several nat 
ural causes, but mainly of the high rate at which all organit 
beings tend to increase. ) 
Curiously enough, Mr. Darwin’s theory is grounded upon the 
doctrine of Malthus and the doctrine of Hobbes. The elder 
DeCandolle had conceived the idea of the struggle for existence, 
and in a passage which would have delighted the cynical philos 
opher of Malmesbury, had declared that all nature is at war, one 
organism with another or with external nature; and Lyell and 
Herbert had made considerable use of it. But Hobbes in his 
theory of society and Darwin in his theory of natural history, 
alone have built their systems upon it. However moralists and 
political economists may regard these doctrines in their or) 
application to human society and the relation of popula 
subsistence, their thorough applicability to the great come 
the organic world in general is now undeniable. And to #6 
Darwin belongs the credit of making this extended applica, 
and of working out the immensely diversified results with rare 
sagacity and untiring patience. He has brought to view 
causes which have been largely operative in the establishes s 
of the actual association and geographical distribution of p 
and animals, In this he must be allowed to have made pe 
1Mportant contribution to an interesting department of scie a 
even if his theory fails in the endeavor to explain the onigit 
diversity of species. a 
“ Nothing is easier,” says our author, “than to admit in phe 
truth of the universal struggle for life, or more difficult—at Jeast ae 
economy of nature, with every fact on distribution, rarity, pera 
extinction, and variation, will be dimly seen or quite misune sunpel* : 
We behold the face of nature bright with gladness, we often SO" 0 
abundance of food ; we do not see, or we forget, that the birds eS -—. 
| ind us mostly live on insects or seeds, and are ‘thet 
stantly destroying life; or we forget how largely these songsters, OF © — 
eggs, or their nestlings, are destroyed by birds and. beasts of ee 
"ae two seeds 2 
