SCIENTIFIC FACTS AND SCIENTIFIC THEORIES

New Zealand Tablet, Volume XXXVI, Issue 21, 28 May 1908, Page 10

SCIENTIFIC FACTS AND SCIENTIFIC THEORIES

CHRISTIAN FAITH V. SHIFTING HYPOTHESES ,

AN ARTICLE THAT EVERY CATHOLIC SHOULD READ

(Concluded from last week). Everybody, one may presume, will have heard of the alchemists and of their search for The Philosopher's Stone, -which was supposed to possess the power of transmuting one substance into another ; of making, for example, gold out of lead. This search was based upon the underlying theory that there was a 'materia prima' of which all substances were different manifestations, and the search itself was valuable in that it led to the emergence of the great science of chemistry.

Kobert Boyle^-'the Father of Chemistry, and the Brother of the Earl of Cork,' as his tombstone describes him— a very distinguished exponent of his ■ science, wrote, in 1681, a work called 'The Skyptical Chemist,' which was the commencement of the movement which displaced the view of the alchemists that there was a 'simple, perfect essence,' and replaced it by the theory that there existed some seventy or eighty elements which- were unchangeable and undecomposable. It is fair to say that the view that these elements were unchangeable was always guarded by careful men of science with the proviso that they were unchangeable so far as could be seen. Thus Davy stated in 1811 that 'to inquire whether the metals be capable of being decomposed and composed is a grand object of true philosophy/ and Faraday, in 1815, that 'to decompose the metals, to reform them, and to realise the once absurd notion of transmutation, are the problems now given to chemists for solution.' But in spite of assertions such as this, it is fair to say that all chemical work for more than two hundred years proceeded upon the assumption that the simplicity of the elements was a scientific fact. , And yet recent discoveries seem to show that the fact was in reality only a theory, and that theory not an accurate one ; nay, more, that the alchemists in their underlying assumption were nearer to the truth than the many generations of chemists which succeeded them. To justify this statement it must be explained in the first place that some twenty-five years ago Sir Norman Lockyer showed, by spectroscopic methods, that a certain element, which he called helium, at that time not known to exist upon the earth, was to be found in abundance in the atmosphere of the sun. Now recent research seems to show that this helium is a disintegration product of radium, and if that is the ease, then one form of matter has been caught in the act of transmuting itself into another. Moreover, there is some evidence that radium itself is a disintegration product from some other substance, perhaps the hitherto called element uranium, or, as others hold, of some unknown substance which accompanies uranium. Finally, the element thorium appears to be constantly engaged in generating from itself another solid element which again decays, its end-product being so far unknown. These facts, if they be facts, are the result of but a few years' investigations; for it is but yesterday that M. and Mme. Curie announced their discovery of radium. Yet they have rendered insecure the whole basis upon which chemists have been working for more than two hundred years, and strikingly illustrate the truth of the statement that great hesitation should be exhibited before scientific facts are regarded as being surely and irrefragably established. But far beyond the points above dealt with is the view which is now being put forward that all matter is one in its last analysis. That the molecules of which any substance is made up are composed of certain factors called atoms has long been a dictum of science, and the atomic theory, so wonderful and so fruitful, is built 'upon it. " But it is now urged that these atoms consist of corpuscles or electrons, and that each of these is made up of a moving unit of negative electricity together with the ether which is bound up with it. A collection 'of such corpuscles, surrounded and balanced by a sphere of positive electricity, is an atom. Hence in essence there is no difference 'between the corpuscles of any substances. It is their arrangement in the atom, their positions with regard to one another, perhaps the kinks or vortices which they produce in the ether surrounding them, or which exist in that ether, which produce the differences in the atoms and hence -produce the differences in the substances of which they are the constituent parts. If all this be true then it is not too much to expect that some means may yet' be found by which the arrangement of the corpuscles in the atom may be artificially altered, and one substance actually transmuted into another. Incidentally I may remark that besides rehabilitating the alchemists, this-view-so far as I understand such matters, comes uncommonly close to the scholastic theory of matter and form. What I have said shows, I think I may claim, that even a theory of such respectable antiquity and such apparently unimpeachable validity as that of the chemical elements may turn out to have been inaccurate, and that, if such be the case, it is

a strong proof of the wisdom which bids one hesitate before rashly forming a judgment as "to any hypothesis or its bearing upon any other order of thought. Turning to the other side of scientific investigation, I must dwell for a few moments on the so-called Darwinian Theory, and in doing so, it may be well first to clear up the misapprehension under which so many persons labour, that Darwin was the originator of the doctrine of transformation, of the view, that is, that certain living things were derived from other living things, the theory of what we should call Derivative Creation. Darwin, of course, did nothing of the kind, for such a solution of the condition of affairs in the world of living things was proposed centuries before Darwin was born. To take only our own theologians, such a view was in essence put forward by St. Augustine, by St. Thomas Aquinas, by Cornelius a Lapide, and by Suarez, as has been shown by Mivart in a now almost forgotten book, 'The Genesis of Species,' and by Father Wasmann in his splendid treatise, 'Die Moderne Biologic und die Entwicklungstheorie,' so that, whether true or not, the doctrine in one shape or another has a very respectable antiquity. What Darwin did was to suggest a means by which the transformation might have taken place, and his great factor was Natural Selection. The title of his most celebrated work— a title unknown to many who talk and write about the subject, at least, so it would appear— is 'The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life,' and this makes it clear that it was the method, not the fact, of transformation which he desired primarily to expound. Now many hold that Natural Selection does not exist, and Professor T. H. Morgan, a most distinguished American authority in biological matters, says that the discoveries of the Augustinian Abbot Mendel have given that theory its coup de grace. But if Natural Selection exists, it is nothing,' and can be nothing, but a sieve by which certain change^ which have in some way or another arisen, are tried and retained or lost. It postulates an internal force of variation following some law, and that again demands the existence of a law and of a law-giver. But let that pass. Darwin called these variations spontaneous, and he insisted' particularly that they were individually slight, minute, and insensible. On such an hypothesis most biologists, and at first all, have pursued their work. But of recent years another school has arisen which declares that these slight, almost unnoticeable changes on which Darwin relied, are utterly powerless to bring about any transformation, and that it is only by the occurrence— the sudden occurrence— of large and considerable changes or 'mutations 3 that a new species is produced. De Vries, the distinguished Dutch botanist, claims that he has been able to observe the birth of new species in the vegetable kingdom, and he and Bateson and others proclaim that Variation is discontinuous and not continuous ; in other words, that the accumulation of small variations which "Darwin counted on, and the efficacy of which Mivart doubted, have nothing to do with the process. It is true that others have cast doubt on the reality of these species, so that the matter Must Still be Considered sub judice, but in any case, if these 'mutations' really occur, we are brought back to the imperative necessity for some internal cause which produces these large spontaneous departures from the normal condition, and to the equally imperative necessity for a law to regulate them and for a law-giver who has established them and set them in motion. I take this instance because the hypotheses of Natural Selection and of the -efficacy of small variations in the production of species really lie at the bottom of the whole of the Darwinian edifice. These theories were supported with all the marvellous skill and with all the industry and research which were the attributes of that truly great man, yet we now find them controverted, and learn that it is possible that they too may have to find their way to the scrap-heap of which I have spoken, a scrap-heap on which will be found also Darwin's beloved 'pangenesis' theory and perhaps some other of his hypotheses. ' That these theories should have found their way there in no way detracts from the greatness of the man or

the remarkable power which his work has had in stimulating scientific research. It merely proves that fresh facts, of which he was not cognisant, have come to light, facts which upset or seem to upset his theories. But it affords another proof of the extraordinary caution which we should adopt in dealing with scientific hypotheses, the scepticism with which they should be received/ and the importance of constantly keeping before one's' mind the fact that the hypo.thesis, however alluring, is only a working hypothesis, and that it must not.be estimated at a higher value than that which it really possesses. Ou the whole, then, I -hope I have been able to show by the examples which I have chosen, and I might have added many others to them, that A Scientific Hypothesis is by no Means Necessarily a Scientific Truth. T also wish to emphasise the point that this is a matter which is perfectly well understood by men of science, ' and that the reason why there is any doubt at all about it in the minds of the public, is that the public relies for its information upon unreliable manuals and articles which, for effect, pick up a theory and flaunt it in the face of that public as if it were a fact as undeniable as sunrise and sunset, and moreover often draw from it deductions which are frequently unwarrantable and almost always absent from the minds, or at least the books, of the real originators of the main hypothesis. And so, to any one worried by the bearing, or supposed bearing, of any scientific hypothesis upon matters close to his heart, I would say, 'Do not be worried ; Theories come and go, but God remains for ever, and there can be no possible ultimate contradiction or difference between the tenets of His Church and the laws of His creation.' There is just one other point which I should wish to dwell upon for a moment. The extraordinary results of science during the past fifty years, the remarkable fecundity of observation in all branches, the almost incredible progress which has been made, all tend to show the wonderful complexity of the problems with which we have_to do and the truly amazing extent of our ignorance. If there is a science in which it might be supposed that really definite knowledge had been arrived at it is that of physics, yet it is not, perhaps, too much to say that physicists are beginning to come to the conclusion that they know nothing of the underlying physical facts of which ordinary things and phenomena are the symbol and the manifestation. The same is true on the biological side. The greater the improvements in the microscope, the more subtle the methods of microscopic preparation, the more delicate and searching the experiments undertaken, the greater are the mysteries which are found to surround us. There is nothing on which greater pains and study have been expended than on the Structure and Physiology of the Cell, and, to us as Catholics, I may add that it is matter of congratulation that some of the most important and fruitful of this work has been done in the University of Louvain. It is a small thing — the cell. It might have been supposed by the casual observer that no very great amount of labour would be necessary to clear up all that could possibly be known of such a very limited field of investigation. Yet after so many years of work, after the unceasing toil of hundreds of observers in all parts of the world, the leading authority on the subject finds himself compelled to write, 'The recent advance of discovery has not tended to simplify our conceptions of cell-life, but has rather led to an emphasised sense of the diversity and complexity of its problems. ' The sea by the side of which Sir Isaac Newton picked up his pebbles is a much greater one than even he imagined, and the pebbles which remain to be picked up are a million for every- one on which .a discoverer has as yet laid Mbhand. How can we then, in the presence of such a confession of ignorance, feel any great confidence in the foundation or longevity of a scientific theory when we know not the day in which some new pebble may not be picked up which will shatter that theory into fragments, as that -fine pebble, radium, has shattered so many pre-existing views.

Pulchra quae videntur, pulchriora quae existimantur, longe pulcherrima quae ignorantur. We have not come to the confines of knowledge as yet nor anywhere near them. We cannot understand the flower from the crannied wall, nor even grasp the secrets of one of the many million cells of which it is built up^ and it is improbable that future generations will succeed in clearing up all the mysteries which elude our grasp. But till all these have been cleared up it is hard to say that any scientific hypothesis is irrefutably established. Facts let us have in as great a measure as possible and theories, too, let us have, in any reasonable number: but let us be quite clear as to what are facts and what are theories, and quite definite in our ideas as to the relative value of the two categories.