528 
NATURE 
[April 5, 1883 
must have responded in the ways they do, or have responded at 
all to the environment, I meant only that the theory ought to 
fulfil the conditions which other physical theories are bound to 
satisfy, z.e. to account for the principal facts of the case. I had 
no reference to any subsidiary hypothesis which might help the 
matter. Dr. Romanes rightly says that it lies not with the evo- 
lutionist to show that variations may not have been intellectually 
planned or guided. But when he assigns the whole results to 
known physical causes and discards the factor of intelligence, 
he is bound to render their adequacy at the least conceivable. 
It may now be seen, I trust (and the context might have made 
it clear), that, in asking Dr. Romanes if he was quite sure that 
any other cause than intelligence could adapt organisms to their 
environment gradually, I was not inviting him to guesses ‘‘ about 
the possibilities of supernatural creation,” but to a reconsidera- 
tion of his antithesis between special (and as he will have it, 
sudden) creation, requiring intelligence, and gradual evolution, 
which might dispense with it ; and I was intimating that he had 
not shown how the latter could dispense with it. The problem 
was : Given plants and animals with certain structures and certain 
adaptations to their environment, to be changed into other forms 
with other structures equally well adapted to a more or less 
changed environment, how to do this solely by the action of 
said environment. Answer: By the killing out of all which 
have not somehow or other acquired the particular structure and 
adaptation they needed. 
But now comes an important qualification : ‘‘ The evolutionist 
may freely admit that natural selection has probably not been the 
only physical cause at work, and even that the variations sup- 
plied to natural selection may not have been wholly fortuitous, 
but may have occurred along favourable lines as responses of 
the organisms to their physical surroundings” ; and Dr, Romanes 
calls my attention to a statement of his that it may be so in an essay 
which I regret that I have not read. He continues, however : 
**But such admissions would make no change in the logical 
aspect of the case; for, however many supplementary causes of 
this kind we may choose to imagine as possible, the evolutionist 
is bound to regard them as all alike in this: that they are of a 
physical or natural kind.” 
“« Physical or natural kind.” The agency which explained 
away all implication of design was in the strict sense physical, 
being the action of the environment on the organisms. 
now extended to whatever is zatwra/, that is, to whatever occurs 
in the course of nature, presumably under established laws ; and 
it is assumed that whatever so occurs is thereby void of all 
evidence of intellectual intention (we need not regard the differ- 
ence—if any there be in such relations—between general and 
special design, the question being wholly one about the grounds 
of any evidence of design in nature), To me it is wholly 
probable that existing species and their special adaptations 
became what they are in the course of nature. And my argu- 
ment is that, if ‘‘such a purely physical cause as natural selec- 
tion” leaves these adaptations still unaccounted for, whatever 
implication of designed origination there formerly was still | 
holds, and may hold, although the series of natural causes be 
practically endless. 
Then as to such causes being all of a piece, so that pure 
physics may explain all biology. Doubtless in a certain sense 
all nature is of a piece. But in another sense—the very one we 
are concerned with—it is of at least two pieces ; no matter how 
it came to be so. One of them is pervaded by an element of its 
own—that of direction of action to ends—which is more and more 
manifested as we rise in the scale of being, but is characteristic 
of all organisms. That seems to lay a foundation for a difference 
in the quality of the ‘‘inference which can be drawn by the 
human mind [guoad design] from the province of natural science ” 
This difference might have made Dr. Romanes hesitate to draw, 
from scientific premisses, the downright conclusion that ‘‘ the 
facts of organic nature present no evidence of design of a quality 
other or better than any of the facts of inorganic nature.” 
Here lies our whole contention. We agree that natural 
science leaves aside the question whether evolution and design 
in nature are compatible or not, this being only a phase of the 
enigma which was as puzzling before evolution was dominant as 
itis now. Wesuppose, too, that the difficulty of conceiving how 
design can coexist with the natural evolution of organisms is 
fairly balanced by the difficulty of conceiving how the phe- 
nomena of organic nature can be accounted for without it. The 
point which we have laboured over is that, if science has no call 
to settle the question, it has none to prejudge it. It was only 
It is | 
| question was valid, and even cogent. 
because Dr. Romanes seemed to me unwittingly to have done so, 
that I ventured the criticisms which opened this discussion. 
Cambridge, Mass., U.S. ASA GRAY 
P.S.—A brief note upon Mr. Hannay’s letter, NATURE, 
vol. xxvii. p. 364, referring to my supposition of successive 
generations slowly changing, ‘‘ yet always so as to bein compatible 
relations to the environment.’ We remarks, this ‘‘is just such a 
statement as ‘Design’ would require, but cannot be held by 
scientific evolutionists, otherwise why are there so many extinct 
species?” Surely it could be held by the soundest of evolu- 
tionists, for it is of the very essence of Darwinism. Are not 
the individuals which compose the present fauna and flora in 
compatible relations to the environment, and is not the extinc- 
tion of species going on? In human society do we consider 
that the unmarried and the childless members of the community 
are not in compatible relations to their surroundings? Is there 
any reason to suppose that the individuals of a flora of earlier 
times—say of the Miocene—were not on the whole in as orderly 
and compatible relations as the existing flora is? It is not chaos 
but cosmos that true Darwinism has in mind, common though 
the contrary impression be. A. G. 
Pror. Asa Gray is kind enough to remark that he has read 
my reply to his previous communication with interest. I should 
like to say, 7 imine, that I have read his reply to me not only 
with interest but with profit ; for it is not often that one meets 
with an argument so carefully thought out and so clearly pre- 
sented. Therefore, if I seek to meet hi; further criticisms, it is 
not in any spirit of controversy that I do so, but solely for the 
sake of endeavouring to help, so far as I am able, in determining 
the true logical position of an important question. 
This question, as Prof. Gray observes, is a narrow one, and I 
shall keep to it. Without therefore trespassing upon the wider 
question of Theism as a whole, our discussion is confined to 
“an inquiry whether certain inferences may or may not sczen- 
tifically be drawn from certain premises.” 
First, I have to meet the dilemma which is put to me when I 
am told that, having said there is no point of logical contact 
between natural science and natural theology, I ought not forth- 
with to say that natural science is competent to destroy an 
inference belonging tv natural theology. But in stating it as 
my opinion that natural science had shown the inference pre- 
viously drawn to be invalid, I did not myself, as my eritic 
asserts, draw any inference (even of a negative kind) from 
natural science to natural theology ; I merely endeavoured to 
point out that an inference previously drawn from the one to the 
other was illegitimate, that inasmuch as the inference proceeded 
from natural science it was liable at any time to be overturned 
by natural science, and that it had now actually been overturned. 
Whether or not, therefore, I was right in saying that there is no 
point of logical contact between natural science and natural 
theology, at least I did not myself endeavour to institute such 
contact. 
But I am told, you admit that long ago the inference in 
Well, I answer in one 
sense it was, but in another and a truer sense it was not. For 
its cogency arose from the hypothesis of special and sudden 
creation on which it rested ; grant this hypothesis, and the infer- 
ence from organic adaptation to intelligent design becomes not 
only cogent but inevitable. The hypothesis, however, was not 
one that really belonged to natural science, and it was just this 
hypothesis that constituted the ‘fictitious logical connection” 
alluded to in the passage which Prof. Gray quotes from my pre- 
vious letter. The facts presented by science remain, of course, 
-yery much the same as they were; but it does not follow that, 
in the absence of the special creation hypothesis, ‘‘ whatever 
evidences of intellectual origination these manifested were seer ir 
the things themselves, and we suppose are to be seen there still.’” 
Let us take an illustration. In the last issue of NATURE 
there is a letter from Prof. Darwin describing the formation of 
mudballs by a suitable and rare combination of natural causes. 
He and his brother did not see these balls in process of forma- 
tion, and therefore he says, ‘‘On seeing the first one or two, 
they looked to us like the handiwork of some boy with an 
enthusiasm for mud pies” ; but their number and the constancy 
of their situation on the slopes of hills—z.e. further knowledge 
of the inferred conditions of their origin—afterwards disposed 
of the teleological hypothesis in favour of a physical one. Now 
here it is equally true that ‘‘ whatever evidences of intellectual 
