168 NATURAL SELECTION VIII 
fresh evidence to clear up those points which all admit to be 
full of doubt,—on other and not less obscure and difficult 
questions a considerable amount of dogmatism is exhibited ; 
doctrines are put forward as established truths, no doubt or 
hesitation is admitted, and it seems to be supposed that no 
further evidence is required, or that any new facts can 
modify our convictions. This is especially the case when we 
inquire, — Are the various forms under which man now 
exists primitive, or derived from pre-existing forms; in 
other words, is man of one or many species? To this ques- 
tion we immediately obtain distinct answers diametrically 
opposed to each other: the one party positively maintaining 
that man is a species and is essentially one—that all differences 
are but local and temporary variations, produced by the 
different physical and moral conditions by which he is 
surrounded; the other party maintaining with equal con- 
fidence that man is a genus of many species, each of which 
is practically unchangeable, and has ever been as distinct, or 
even more distinct, than we now behold them. This differ- 
ence of opinion is somewhat remarkable, when we consider 
that both parties are well acquainted with the subject ; both 
use the same vast accumulation of facts; both reject those 
early traditions of mankind which profess to give an account 
of his origin; and both declare that they are seeking fear- 
lessly after truth alone; yet each will persist in looking only 
at the portion of truth on his own side of the question, and at 
the error which is mingled with his opponent’s doctrine. It 
is my wish to show how the two opposing views can be com- 
bined, so as to eliminate the error and retain the truth in 
each, and it is by means of Mr. Darwin’s celebrated theory 
of Natural Selection that I hope to do this, and thus to har- 
monise the conflicting theories of modern anthropologists. 
Let us first see what each party has to say for itself. In 
favour of the unity of mankind it is argued that there are 
no races without transitions to others; that every race 
exhibits within itself variations of colour, of hair, of feature, 
and of form, to such a degree as to bridge over, to a large 
extent, the gap that separates it from other races. It is 
asserted that no race is homogeneous ; that there is a tend- 
ency to vary; that climate, food, and habits produce, and 
