Dewar And Evolution
0 NE of the most admirable characteristics of the medixval thinkers was their willingness, nay, their anxiety, to collect and state, as forcefully as possible, the objections to their own particular views. The " Summa Theologica " of St. Thomas Aquinas is in a sense a compendium of anti-Christian theses, many of which are still considered very useful by our contemporary opponen is.
This excellent habit of facing objections squarely has not been maintained as well as one could wish, in the modern scientific world. The way in which the Victorian scientific pontiffs rathmed the unproved theory of evolution, with a mass of trimmings eventually abandoned, down the throat of the public, affords a very unpleasant example of the state of mind that came to dominate the scientific world. Some of these people, said Samuel Butler bitterly, would put themselves in the Pope's place tomorrow if they had the chance.
Entertainment in Propaganda •
It is no doubt true that there is nothing like listening to an enthusiastic propagandist, if one wants to hear all that can be said for a given thesis. But in the case of evolution the propagandist enthusiasts eventually succeed in silencing the opposition completely. The official scientific world ceased to produce critics and criticisms of evolutionary theory. Debates On questions incidental to the fundamental dogma continued for a time, though of late years even these have become uncommon.
The duties of an official opposition fell into the hands of unscientific eccentrics like the " silver-tongued " orator, William J. Bryan, and the educational authorities of the State of Tennessee.
The academic world confined itself to elaborate explanations, generally devoid of evidential value, of how the present state of things came to be, assuming that the evolutionary theory is true. The theory gradually assumed the status of an accepted fact, which it still possesses. .
I have always felt that this is extremely bad for science. it has seemed to me, also, that the philosophical basis of evolutionary theory is in many ways unsatisfactory. From time to time, therefore, I have, on convenient occasions, published such criticisms of evolutionary doctrine as have occurred to me.
A Classified Critic
As a result of these criticisms, which seemed to me legitimate and necessary, I have been classified by Dr. A. Morley Davies in Evolution and its Modern Critics (1937)—which is his answer to Mr. Douglas Dewar's Difficulties of the Evolution Theory (1931)—as one of the " qualified biologists " who reject evolution. This does not correspond to the facts. As readers of this paper may remember, I went to some trouble, a few years ago, to defend the theory, as a theory, against Mr. Arnold Lunn in these columns; and I think that Dr. Davies might have taken the trouble to find out what my views were, before defining them.
However, I have explained my position at some length in Science and Common Sense, of which the final proofs had been corrected when, through the courtesy of Dr. Davies, I received a copy of his book; and I hope now to have made it clear that I consider the theory of evolution as a legitimate theory .in natural science, though I think that it involves many difficulties and do not feel called upon to accept it as a creed.
" No Theological Difficulties" Mr. Douglas Dewar, though he was, I believe, at one time a convinced evolutionist, like the great majority of biologists, is a more thorough-going opponent of the
W. R. Thompson, F.R.S.
theory of evolution, though in his latest work he agrees with me that the difficulties involved in it are not theological but rational and experimental, and sees no harm in the theory of evolution in the fullest sense being adopted as an alternative hypothesis to that of creation."
His first work on the subject, published 1931, was not very warmly received by the scientific world. One of the points Mr. Dewar made in it concerned what is called " the imperfection of the geological record." If the various species of living forms have developed one from the other through a series of gradual transitions, the intermediate stages should be abundantly represented by fossils; the various hypothetical stages in the development of the various types of wings, for example, ought to be fairly easily discoverable, The fact that they have not been discovered is explained away by supposing that they do not happen to have been fossilised or that the strata once containing them have disintegrated.
MI. Dewar attempted to test this theory
by listing the number of mammals now living of which fossils are known. He found that, in India, 75 per cent. of the genera of the terrestrial marnmalia, 20 per cent. of the arboreal and 50 per cent. of the aquatic are now known as fossils. He later extended this enquiry to the mammals of the world and prepared a paper embodying the results, in collaboration with Mr. G. A. I.evett-Yeats. This was submitted to the Zoological Society, of which Mr. Dewar and Mr. Levett-Yeats are Fellows; but the paper was rejected on the ground, says Mr. Dewar, that the results led to no useful conclusions.
Later, a reviewer in Nature, dealing with Dr. Morley's book, suggested that Mr. Dewar failed to appreciate the extreme improbability of the fossilisation of any given type. Mr. Dewar sent in a short letter giving, he says, " statistics demonstrating that the statement in question is hyperbole." Naiure refused to publish this letter.
No Insinuations Allowed I have no first-hand knowledge of these incidents, and do not think it is fair to condemn Nature and the Zoological Society unheard. But the available evidence suggests to me that while the official scientific world is ready to tolerate any amount of argument as to the cause and mechanism of evolution, it closes its ears firmly to any insinuations that life and living things have originated by anything but a purely natural process, or that a supernatural power has guided the course of events, or has, at certaM points, intervened in it. It is, of course, true that to admit the non-natural character of evolution would be tantamount to throwing the principal problem of biology right out of the scientific field.
For many students of natural science, this would look like a kind of intellectual suicide, a desperate step which nothing but the exhaustion of the store of hypotheses proper to natural science would justify.
Nevertheless, the stubborn refusal to consider any anti-evolutionary argument that seems likely to lead to a theological conclusion is certainly against the interests of natural science, which, after all, is simply a special application of rational thinking. If scientific argument is to be permanently deflected by anti-Christian bias, the only hope for critical biology will be to take philosophical anarchism as a basis and to ask the evolutionist why, after all, the processes-of nature should lend themselves to rational description. I should not be surprised if an anti-evolutionary dialectic eventually develops along this line.
Superficial Knowledge In the meantime, we must, I feel, he grateful to Mr. Dewar for hammering away with his anti-evolutionary criticism and we must not forget Dr. Davies for taking Mr. Dewar seriously. One may, however, venture to suggest that Dr. Davies might take the trouble to acquaint himself more fully with anti-evolutionary literature, of which his knowledge, to judge by his hook, is still extremely superficial.
Mr. Dewar, on his side, might take a little more trOuble with his facts and arguments. Though his book contains much that is interesting and suggestive, some of the statements he makes about matters in my own special field make me wonder as to his accuracy in other departments of biology. Thus on pp. 45 and 46, he quotes without criticism an account of metamorphosis in butterflies, so crudely inaccurate, that one would not tolerate it from a firstyear student of biology. On p. 47, he asks why animal larvm never breed lame, though we have known for more than 50 years that some insects actually do this, the most familiar example being the fungus-gnats of the genus Miastor.
Mr. .Dewar's assertion (p. 43), that to class the parasite Sacculina with the Crustacea, as modern systematists insist on doing, " tends to bring Zoology into disrepute," is, I consider, indefensible. The anatomical characters of the initial stages of this animal are clearly Crustacean and even in the parasitic stage the disposition of the parts is similar to that of the aduli barnacles, with which Sacculina is classified. Mr. Dewar's attempt to show that their characters have no value in relation to classification, but are merely immediately useful, or " adaptive " characters, is quite unconvincing. No doubt the structural ground-plan which the Sacculina larva shares with the lariat of the non-parasitic Cirripedes and other Crustacea is "adaptive" in the sense that it is one of the anatomical plans compatible with existence; but it is impossible to show that it is so precisely related to the mode of life, that it has no value whatever in establishing the animal's place in the system of classification. And whether we accept the theory of evolution or not, we should still class Sacculina with the Crustacea because of its structural ground-plan.
The careless arguments and loose language of evolutionists is severely criticised by Mr. Dewar, not without reason. Unless he• is more careful about his own arguments we fear that he will not get many zoologists to pay much attention to him.