............Mr. Darwin explains this apparent inconsistency thus:--He
maintains that though the advantageous modification itself is
fortuitous, or without known cause or principle underlying it, yet its
becoming the predominant form of the species in which it appears is
due to the fact that those animals which have been advantageously
modified commonly survive in times of difficulty, while the unmodified
individuals perish: offspring therefore is more frequently left by the
favourably modified animal, and thus little by little the whole
species will come to inherit the modification. Hence the survival of
the fittest becomes a means of modification, though it is no cause of
It will appear more clearly later on how much this amounts to. I will
for the present content myself with the following quotation from the
late Mr. G. H. Lewes in reference to it. Mr. Lewes writes:--
"Mr. Darwin seems to imply that the external conditions which cause a
variation are to be distinguished from the conditions which accumulate
and perfect such variation, that is to say, he implies a radical
difference between the process of variation and the process of
selection. This I have already said does not seem to me acceptable;
the selection I conceive to be simply the variation which has
Certainly those animals and plants which are best fitted for their
environment, or, as Lamarck calls it, "_circonstances_"--those
animals, in fact, which are best fitted to comply with the conditions
of their existence--are most likely to survive and transmit their
especial fitness. No one would admit this more readily than Lamarck.
This is no theory; it is a commonly observed fact in nature which no
one will dispute, but it is not more "a means of modification" than
many other commonly observed facts concerning animals.
For "natural selection" substitute the words "survival of the
fittest," which we may do with Mr. Darwin's own consent abundantly
To the words "survival of the fittest" add what is elided, but what
is, nevertheless, unquestionably as much implied as though it were
said openly whenever these words are used, and without which "fittest"
has no force--I mean, "for the conditions of their existence."