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_.
Galileo and his case we shall consider later on, for he and it are
really germane to the question with which we are dealing. The
Inquisition has really nothing to do with the matter. The _Index_ we
also reserve for a later part of this essay. With the _imprimatur_ we
may now deal, since there is no doubt that there is a genuine
misunderstanding on this subject on the part of some people who are
misled perhaps through ignorance of Latin and quite certainly through
ignorance of what the whole matter amounts to. Let us begin by reminding
ourselves that, though the unchanging Church is now, so far as I am
aware, the only body which issues an _imprimatur_, there were other
instances of the exercise of such a privilege even in recent or
comparatively recent days. There were Royal licences to print with which
we need not concern ourselves. But, what is important, there was a time
when the scientific authority of the day assumed the right of issuing an
_imprimatur_. I take the first book which occurs to me, Tyson's
_Anatomie of a Pygmie_, and for the sake of those who are not acquainted
with it, I may add that this book is not only the foundation-stone of
Comparative Anatomy, but also, through its appendix _A Philological
Essay Concerning the Pygmies, the Cynocephali, the Satyrs, and Sphinges
of the Ancients_, the foundation-stone of all folk-lore study. On the
page fronting the title of this work the following appears:
_17 Die Maij, 1699._
_Imprimatur Liber cui Titulus, Orang-Outang sive Homo
Sylvestris, etc. Authore Edvardo Tyson, M.D., R.S.S._
_John Hoskins, V.P.R.S._
What does this mean? In the first place it shows, what all instructed
persons know, that the Royal Society did then exercise the privilege of
giving an _imprimatur_ at any rate to books written by its own Fellows.
It cannot be supposed that such _imprimatur_ guaranteed the accuracy of
all the statements made by Tyson, for we may feel sure that John Hoskins
was quite unable to give any such assurance. We must assume that it
meant that there was nothing in the book which would reflect discredit
upon the Society of which Tyson was a Fellow and from which the
_imprimatur_ was obtained.
However this may be, the sway over its Fellows' publications was
exercised, and indeed very excellent arguments might be adduced for the
reassumption of such a sway even to-day.[26]
Though the _imprimatur_ in question has fallen into desuetude, it is, as
we all know, the commonest of things for the introductions to works of
science to occupy some often considerable part of their space with
acknowledgments of assistance given by learned friends who have read the
manuscript or the proofs and made suggestions with the object of
improving the book or adding to its accuracy. Any person who has written
a book can feel nothing but gratitude towards those who have helped him
to avoid the errors and slips to which even the most careful are
subject.
So that such acknowledgments of assistance have come to be almost what
the lawyers call "common form." What they really amount to is a
proclamation on the part of the author that he has done his best to
ensure that his book is free from mistakes. Now the _imprimatur_ really
amounts to the same thing, for it is, of course, confined to books or
parts of books where theology or philosophy trenching upon theology is
concerned. Thus a book may deal largely, perhaps mainly, with scientific
points, yet necessarily include allusions to theological dogmas. The
_imprimatur_ to such a book would relate solely and entirely to the
theological parts, just as the advice of an architectural authority on a
point connected with that subject in a work in which it was mentioned
only in an incidental manner, would refer to that point, and to nothing
else. Perhaps it should be added, that no author is obliged to obtain an
_imprimatur_ any more than he is compelled to seek advice on any other
point in connection with his book. "_Nihil Obstat_," says the skilled
referee: "I see no reason to suppose that there is anything in all this
which contravenes theological principles." To which the authority
appealed to adds "_imprimatur_:" "Then by all means let it be printed."
The procedure is no doubt somewhat more stately and formal than the
modern system of acknowledgments, yet in actual practice there is but
little to differentiate the two methods of ensuring, so far as is
possible, that the work is free from mistakes. That neither the
assistance of friends nor the _imprimatur_ of authorities is infallible
is proved by the facts that mistakes do creep into works of science,
however carefully examined, and that more than one book with an
_imprimatur_ has, none the less, found its way on to the _Index_. Before
leaving this branch of the subject one cannot refrain from calling
attention to another point. How often in advertisements of books do we
not see quotations from reviews in authoritative journals--a medical
work from the _Lancet_, a physical or chemical from _Nature_? Frequently
too we see "Mr. So-and-So, the well-known authority on the subject, says
of this book, etc., etc." What are all these authoritative commendations
but an _imprimatur_ up to date?