564 
the evidence which supports that belief, and refuse to occupy them 
selves in seeking further evidence.”—(ft. 2j.) 
On the same principle it is possible that other factors may 
have been overlooked by Mr. Spencer, because he has 
taken for granted that there are only three, or that these 
three are sufficient to produce all the phenomena of 
Organic Evolution. 
The result of what has been said is that the contention of 
Mr. Spencer does not justify him in assuming that Natural 
Selection must necessarily have had a part in the transmu 
tation of species, while at the same time he argues most 
conclusively that in some cases Natural Selection could 
not possibly be the cause of transmutation. 
Before I leave Mr. Spencer’s proof of the necessity for 
the introduction of Natural Selection, it may be well to con 
sider his definition of the phrase “the fittest.” There are some 
who regard Natural Selection and the survival of the fittest 
as synonymous terms, and having proved to their own satis 
faction that Natural Selection is a law of nature, it follows 
that there must be a survival of the fittest. But the truth 
is that Natural Selection is the reputed cause, and the 
survival of the fittest is the reputed effect ; and on that 
account the two phrases ought to be kept perfectly dis 
tinct from one another. And yet Mr. Spencer affirms 
that— 
“though Mr. Darwin approved of this expression, and occasionally 
employed it, he did not adopt it for general use ; contending, very 
truly, that the expression ‘ Natural Selection ’ is in some cases more 
convenient.”—(ft. 41—noie.) 
It is difficult to understand the propriety of not using 
the two phrases ; and one is bound to suspect the con 
venience which leads a reasoner to use the term which 
indicates the cause for the term which indicates the effect.