( 20 ) 
Tn leaving the dogma of ‘special creation,” and the assump- 
tion of “ fixity of species” with which it is bound up, it is 
only right to point out how completely the logical foundations 
of both were undermined by the great thinker who has just 
passed away. Years before the appearance of the Darwin- 
Wallace essay, and of the “Origin,” Herbert Spencer wrote 
on “The Development Hypothesis.” * Although of course 
wanting the great motive power to evolution supplied by 
natural selection, this essay is a powerful and convincing 
argument for evolution as against special creation. It is 
astonishing that it did not produce more effect. I may appro- 
priately conclude this section of the Address by quoting the 
results of Herbert Spencer’s critical examination, from every 
point of view, of the Linnean conception of species. “ Thus, 
however regarded, the hypothesis of special creations turns 
out to be worthless—worthless by its derivation ; worthless in 
its intrinsic incoherence; worthless as absolutely without 
evidence; worthless as not supplying an intellectual need ; 
worthless as not satisfying a moral want.” t 
If then the Linnean conception of species—separately created 
and fixed for all time at their creation—has been abandoned, 
what have we to put in itsplace? Ina letter to Hooker, Dee. 
24, 1856, Darwin gave a list of the various definitions he had 
met with. “TI have just been comparing definitions of species, 
and stating briefly how systematic naturalists work out their 
subjects. . . . It is really laughable to see what different 
ideas are prominent in various naturalists’ minds when they 
speak of ‘species’; in some, resemblance is everything, and 
descent of little weight—in some, resemblance seems to go 
for nothing, and creation the reigning idea—in some, descent 
is the key—in some, sterility an unfailing test, with others it 
is not worth a farthing. It all comes, I believe, from trying 
to define the indefinable.” { 
As regards the work done by the systematist, we find that 
Darwin did not agree with those of his friends who thought 
* In the Leader, between January 1852 and May 1854, reprinted in 
‘Essays Scientific, Political, and Speculative.” London, 1868, vol. i, 
Pp. 377. 
+ ‘*The Principles of Biology.”” London, 1864, vol. i, p. 345. 
+ “Life and Letters of Charles Darwin,” London, 1887, vol. ii, 
p. 88. 
