Chapter 5

Samuel Butler, in _Life and Habit_, warns his readers against the dicta of scientific men, and more particularly against his own dicta, though he made no claim to be a scientist. If his reader _must_ believe in something, "let him believe in the music of Handel, the painting of Giovanni Bellini, and in the thirteenth chapter of St. Paul's first Epistle to the Corinthians." And he exclaims: "Let us have no more 'Lo, here!' with the professor; he very rarely knows what he says he knows; no sooner has he misled the world for a sufficient time with a great flourish of trumpets than he is toppled over by one more plausible than himself." That is a somewhat unkind way of putting it; but undoubtedly theory after theory is put forward, and often claimed to be final, only to disappear when another explanation takes its place. Thus at the moment we are in the full flood of the chemical theory which is employed to explain inheritance. That heredity exists we all know, but so far we know nothing about its mechanism. Darwin, with "Pangenesis," and others, using other titles, argued in favour of a "particulate" explanation, but the number of particles which would be necessary to account for the phenomena involved, this and other difficulties, have practically put this explanation out of court. Then we had the Mnemic theory of Hering, Butler, and others, by which the unconscious memory of the embryo--even the germ--is the explanation. Quite lately the mnemic theory has been claimed by Rignano in his _Scientific Synthesis_ as a complete explanation, in forgetfulness of the fact that even the all-powerful protozoon can only remember what has passed and could certainly not _remember_ that it was some day going to breed a man. At the moment, things are explained on a chemical basis, though that basis is far from firm; is of a shifting nature, and a little hazy in details. Some time ago, colloids were the cry. A President of the British Association almost led one to imagine that "the homunculus in the retort" might be expected in a few weeks. But the chemists would have none of this, and denied that the colloids, about which they ought to know more than do the biologists, had that promise in them which had been claimed. We had Leduc and his "fairy flowers," as now we have Loeb and others with their metabolites and hormones. As to these last, there seems to be no kind of doubt that the internal secretions of many organs and structures have effects which were, even a few years ago, quite unsuspected. Those of the thyroid and adrenals are excellent examples.

It seems to be the fate, however, of all supporters of new theories to run into extravagances. Darwin had to remind his enthusiastic disciples that Natural Selection could not create variations, and we may feel some confidence that Hering, were he alive, would urge his followers to bear in mind that memory cannot create a state of affairs which never existed. So far we may certainly say that these internal secretions do produce certain physical effects, some of them effects not to be suspected by the uninformed reader. There seems to be very good evidence that the growth of antlers in deer depends upon an internal secretion from the sex-gland and from the interstitial tissue of that gland; for it is apparently upon the secretions of this portion of the gland that the secondary sexual characters depend, and not merely these, but also the normal sexual instincts. And this takes us a stage further. The extreme claim is that all instincts, in fact all thoughts and operations, are in the last analysis chemical or chemico-physical. Let us examine this claim for a moment. The adrenals are two inconspicuous ductless bodies situated immediately above the kidneys. Not many years ago, when the present writer was a medical student, all that was known about these organs was that when stricken with a certain disease, known as Addison's disease from the name of its first describer, the unfortunate possessor of the diseased glands became of a more or less rich chocolate colour. To-day we know that the internal secretion of these organs is a very powerful styptic, and there is good reason to believe that a copious discharge accompanies an unusual exhibition of rage. When we are told things of this kind we must first of all remember that the adrenalin does not cause the rage, though it may produce its concomitant phenomena. If a man flies into a violent passion because someone has trodden upon his corns, and there is a copious flow of adrenalin from the glands, it is not that flow which has caused his rage. It may be the flow from the interstitial tissue of the sex-glands which engenders sexual feelings, but then those are almost wholly physical, and only in a very minor sense--if even if any true sense--psychical. Persons who take the extreme view have never yet suggested that there is a characteristic hormone connected with those psychical attributes alluded to in the chapter of the Corinthians recommended to our notice by Butler. In fact they seem to ignore all but the lower or vegetable characters when dealing with psychology from the chemico-physical point of view.

Finally, we come again to the fatal and fundamental defect of this as of other "explanations"; it is an explanation "_within the system_," and therefore unphilosophical in so far as it fails to explain the facts through their ultimate or deepest reasons.

A large part of Loeb's book is devoted to a description of the author's remarkable experiments in artificial parthenogenesis, and an attempt to show that they offer a complete explanation. Sir William Tilden, one of the greatest living authorities on organic chemistry, tells us that "too much has been made of the curious observations of J. Loeb and others"; and he definitely states that when we consider "the propagation of the animal races by the sexual process ... there can be no fear of contradiction in the statement that in the whole range of physical and chemical phenomena there is no ground for even a suggestion of an explanation." Behind this pronouncement of an expert, one might well shelter oneself; but the question under consideration merits a little further treatment. The reproduction of kind, though usually a bi-sexual process, may, however, normally in rare cases be uni-sexual, and this process is known as Parthenogenesis. Even in human beings certain tumours of the sex-glands, known as teratomata, very rare in women and even rarer, if ever existent, in men, have been claimed as examples of attempts at parthenogenesis, and so far no better explanation is available.

Now Loeb and others have succeeded in certain forms--even in a vertebrate like the frog--in inducing development in unimpregnated ova. The evidence for all these things is still slender; but we will content ourselves with noting that point and passing on to the consideration of the phenomena and the claims put forward in connection with them. We find the task of unravelling the writer's meaning rendered more difficult by a certain confusion in his use of terms, since fertilisation, _i.e._ syngamy--the union of the different sex products--seems to be confused with segmentation, _i.e._ germination; and this confusion is accentuated by the claim that "the main effect of the spermatozoon in inducing the development of the egg consists in an alteration in the surface of the latter which is apparently of the nature of a cytolysis of the cortical layer. Anything that causes this alteration without endangering the rest of the egg may induce its development." When the spermatozoon enters the ovum it causes some alteration in the surface membrane of the latter which, amongst other things, prevents the entrance of further spermatozoa. Loeb thinks that in causing this alteration it sets up the segmentation of the ovum. That there is a close connection between the two events seems undoubted; that they are in relation of cause and effect seems likely. It is quite evident that an artificial stimulus can in certain cases set up segmentation, but never can it cause the fertilisation of the ovum. It may very likely produce the same change in the membrane that is caused by the entrance of the spermatozoon under normal circumstances--membrane formation may be necessarily coincident with the liberation in the egg of some zymose which arises from a pre-existent zymogen. But we are still some way off any assurance that the _main_ object of the spermatozoon in inducing the development of the egg is this surface alteration. It may be the initial effect; very probably it is; but since the main function of the spermatozoon must be the introduction of germplasm from the male parent, it is too much for anyone to ask us to believe that its _main_ function is concerned with surface alteration.

Loeb argues that the change in the surface membrane is of a chemical character, and that no doubt may be correct; but even if we allow him every scientific fact, or surmise, he is still, as in the other cases with which we have dealt, miles away from any real explanation. He is still inside his chemico-physical explanation to begin with; and, even within that, he still leaves us anxious for the explanation of a number of points--for example, as to the nature of the chemical process which accompanies, or is the cause of, segmentation. We in no way press these questions; for similar demands could be made in so many cases; we only indicate that they are there. What we do press is this--that when an authority comes forward to assure us that all the processes of life, including man's highest as well as his lowest attributes, can be explained on chemico-physical lines, we are entitled to ask for a more cogent proof of it than the demonstration, however complete, of the germination of an egg, caused by artificial stimulus and not by the ordinary method of syngamy, even though that germination may lead to the production of a perfect adult form. We are entitled to ask him to make clear to us not only what is happening _within his system_, but--which is far more important--what that system is, and how it came into existence. We are entitled to ask why the artificial stimulus, or the entry of the spermatozoon, produces the effects which it is claimed to produce instead of any one of some score of other effects which it might conceivably have produced. Above all we are entitled to ask why there are any effects, or even why there is any ovum or any spermatozoon or curious physiological investigator, to give the artificial stimulus. Until some light is thrown upon these things we are still within the system, or merely hovering round its confines, and are far away from any final or philosophical explanation such as would satisfy the mind of the man who wants to get a real and not a partial knowledge of the things around him.

We may now turn to the question of Vitalism. It was long the regnant theory; then temporarily the Cinderella of biology; it is now returning to its early position, though still denied by those of the older school of thought who cannot imagine the kitchen wench of yesterday the ruler of to-day. One of the objections to Vitalism is that this explanation of living things is thought by ignorant writers to be so inextricably mixed up with theological considerations as to furnish a case of _stantis aut cadentis ecclesiae_. That is, of course, absurd; but it creates an undoubted bias against the theory. Hence it is the fashion amongst its opponents to write of it as "mystical" or, as Loeb does, as "supernatural," probably the most illogical term that could possibly be used. What is Vitalism? It is the theory that there is some other element--call it entelechy with Driesch, or call it what you like--in living things than those elements known to chemistry and physics. If it is _not_ there, _cadit quaestio_; if it _is_ there it is not "supernatural." It might with reason be called "super-mechanical," or "super-chemical," or "super-physical"; but if it is in Nature, as it is held to be, it is not "supernatural" in any true sense of that word--no dictionary confines the term "Nature" to the operations of chemistry and physics.

A good deal of the misconception existing on this point comes from pure ignorance of philosophy, a subject with which writers of this school seldom have even a nodding acquaintance. "The idea of a quasi-superhuman intelligence presiding over the forces of the living is met with in the field of regeneration." Echoes of the Cartesian idea of the soul seem to ring in this statement; but it could not have been written by anyone who had mastered the Aristotelian or the Scholastic explanation of matter and form. But let us take this question of Regeneration; the power which all living things have, in some measure, though in very different measure, of reconstructing themselves when injured. It has been dealt with in a masterly manner by Driesch; and we may at once say that we do not think that Loeb has in any way contraverted his argument, nor even entered the first line of defence of that which is built up around what he calls by the somewhat forbidding name of "Harmonious-Equipotential System."

Let us take one particular example, a very remarkable one, which has been cited by both writers--Wolff's experiment on the lens of the eye. The lens is just behind the pupil or central aperture in the iris or coloured ring at the front of the eye, and behind the cornea which is to the eye what a watch-glass is to a watch. If the lens of the eye be removed from a newt, as it is from human beings in the operation for cataract, the animal will grow another one. How does it do it? In certain cases a tiny fragment of the lens has been left behind after the operation, and the new one grows from that. This is sufficiently wonderful, but by no means so wonderful as what happens in other cases in which the entire lens has been removed and the new lens grows from the outer pigmented layer of the margin of the iris. To the unbiological reader one source of origin will not seem more wonderful than the other, but there is really a vast distinction between them. At an early stage in the development of the embryo, the cells composing it become divisible into three layers. It is even possible, as Loeb maintains, that this differentiation is present in the unsegmented ovum, in which case the facts to be detailed become still more remarkable and significant. These layers are known as epi-, meso-, and hypo-blast; and from each one of them arise certain portions of the body, and certain portions only. It would be as remarkable to a biologist to find these layers not breeding true as it would to a fowl-fancier to discover that the eggs of his Buff Orpingtons were producing young turkeys or ducks. Now the lens is an epiblastic structure, and the iris is mesoblastic. Hence the wonder with which we are filled when we find the iris growing a lens. Loeb attempts to explain this in the first instance by telling us that the cells of the iris cannot grow and develop as long as they are pigmented; that the operation wounds the iris, allows pigment to escape, and thus permits of proliferation. We may accept this, and yet ask why it takes on a form of growth familiar to us only in connection with epiblast? The reply is: "Young cells when put into the optic cup always become transparent, no matter what their origin; it looks as if this were due to a chemical influence, exercised by the optic cup or by the liquid it contains.

"Lewis has shown that when the optic cup is transplanted into any other place under the epithelium of a larva of a frog the epithelium will always grow into the cup where the latter comes in contact with the epithelium; and that the ingrowing part will always become transparent." A most remarkable and interesting experiment; it has this very important limitation--that it is always _epithelium_ with which it has to do, whereas in Wolff's experiment the regeneration takes place from mesoblastic tissue. The cause of the transparency may be a chemical reaction--it depends a good deal upon our definition of that phrase. Is protoplasm a chemical compound? Some have considered it so, and spoken of its marvellously complicated molecule. Of course it is made up of carbon, hydrogen, and other substances within the domain of chemistry. But is it, therefore, merely a chemical compound? The reply involves the whole riddle of Vitalism. The author would say that it, as well as all the living things to which it belongs, is purely and solely a chemical compound; and he must take the consequences of his belief. One of these consequences, from which doubtless he would not shrink, would be that a super-chemist (so to speak) could write him and his experiments and his book down in a series of chemical formulæ--a consequence which takes a good deal of believing. But it also involves him in a belief in the rigidity of chemical reactions; and we are entitled to ask for an explanation of the identical behaviour of the chemical reaction in connection with epiblastic and mesoblastic cells--both pure chemical compounds _ex hypothesi_ and, as far as we can tell from their normal behaviour, widely differing from one another. The optic cup, or its contained fluid, is one chemical compound; epithelium is another; mesoblast is a third. We want an explanation of the identical behaviour of the first with _either_ of the two latter; and this should be borne in mind--that the reaction is not a mere matter of "clearing" of a tissue as the histologist would clear his section by oil-of-cloves or other reagent, but of the construction of a different type of cell--epithelial, not connective tissue.

It certainly follows that there must be some superior, at least widely different, agency at work than one of a purely chemical character--something which transcends chemical operations. This is precisely what the Vitalist claims. No one will fail to award praise to any attempts to explain the phenomena of Nature, whether within or without any system. Loeb's book sets out to do a great deal more--to explain what it does not explain--the Organism as a Whole, and thus to give a philosophical explanation of man. It even claims to afford hints for a rule for his life, at least so we gather from the Preface, where, alluding to "that group of freethinkers, including d'Alembert, Diderot, Holbach and Voltaire," the author tells us that they "first dared to follow the consequences of a mechanistic science--incomplete as it then was--to the rules of human conduct, and thereby laid the foundation of that spirit of tolerance, justice, and gentleness which was the hope of our civilisation until it was buried under the wave of homicidal emotion which has swept through the world." On which it is surely reasonable to ask how a chemical reaction can learn so to alter itself as to exhibit "tolerance, justice, and gentleness," attributes which it had not previously possessed? Such claims of this and other writers, who would find in the laws of Nature as formulated to-day (forgetful that their formulæ may to-morrow be cast into the furnace) a rule of life as well as a full explanation of the cosmos, resemble in their lack of base an inverted pyramid.

IV. SCIENCE IN "BONDAGE"

Amongst the numerous taunts which are cast at the Catholic Church there is none more frequently employed, nor, it may be added, more generally believed, nor more injurious to her reputation amongst outsiders--even with her own less-instructed children themselves at times--than the allegation which declares that where the Church has full sway, science cannot flourish, can scarcely in fact exist, and that the Church will only permit men of science to study and to teach as and while she permits.

To give but one example of this attitude towards the Church, readers may be reminded that Huxley[23] called the Catholic Church "the vigorous enemy of the highest life of mankind," and rejoiced that evolution, "in addition to its truth, has the great merit of being in a position of irreconcilable antagonism to it." An utterly incorrect, even ignorant statement, by the way--but let that pass. The same writer, in a number of places, in season and out of season, as we may fairly say,[24] proclaims his wholly erroneous view that there is "a necessary antagonism between science and Roman Catholic doctrine." We need not labour this point. It is sufficiently obvious, nor does it need any catena of authorities to establish the fact, that outside the Church, and even, as we have hinted above, amongst the less-instructed of her own children, there is a prevalent idea that the allegation with which this paper proposes to deal is a true bill.

Those who give credit to the allegation must of course ignore certain very patent facts which are, it will be allowed, a little difficult to get over. They must commence by ignoring the historical fact that the greater number--almost all indeed--of the older Universities, places specially intended to foster and increase knowledge and research, owe their origin to Papal bulls. They must ignore the fact that vast numbers of scientific researches, often of fundamental importance, especially perhaps in the subjects of anatomy and physiology, emanated from learned men attached to seats of learning in Rome, and this during the Middle Ages, and that the learned men who were their authors quite frequently held official positions in the Papal Court. They must finally ignore the fact that a large number of the most distinguished scientific workers and discoverers in the past were also devout children of the Catholic Church. Stensen, "the Father of Geology" and a great anatomical discoverer as well, was a bishop; Mendel, whose name is so often heard nowadays in biological controversies, was an abbot. And what about Galvani, Volta, Pasteur, Schwann (the originator of the Cell Theory), van Beneden, Johannes Müller, admitted by Huxley to be "the greatest anatomist and physiologist among my contemporaries"?[25] What about Kircher, Spallanzani, Secchi, de Lapparent, to take the names of persons of different historical periods, and connected with different subjects, yet all united in the bond of the Faith? To point to these men--and a host of other names might be cited--is to overthrow at once and finally the edifice of falsehood reared by enemies of the Church, who, before erecting it, might reasonably have been asked to look to the security of their foundations.

Still there is the edifice, and as every edifice must rest on some kind of foundation or another, even if that foundation be nothing but sand, it may be useful and interesting to inquire, as I now propose to do, what foundation there is--if in fact there is any--for this particular allegation.

We might commence by interrogating the persons who make it. The probability is that the reply which would at once be drawn from most of them would amount to this: "Everybody knows it to be true." If the interrogated person is amongst those less imperfectly informed we shall probably be referred to Huxley or to some other writer. Or we may even find ourselves confronted with that greater knowledge--or less inspissated ignorance--which babbles about Galileo, the Inquisition, the _Index_, and the _imprimatur_.