controverted question of the evidences of the production of the lowest
and most rudimentary forms of life from inorganic matter, it may be
stated as certain that there is no rational and educated person,
whatever his religious beliefs or philosophical views, who is not
convinced that every individual animal or plant, sufficiently highly
organised to deserve such distinctive appellation, now existing upon the
world, has been produced from pre-existing parents by the operation of a
series of processes of the order to which the term natural is commonly
applied. These processes are also fundamentally the same throughout the
whole range of living beings, however much modified in detail to suit
the various manifestations under which those beings are presented to us.
We feel absolutely certain, when we see a horse, a bird, a butterfly, or
an oak-tree, that each was derived from pre-existing parents, more or
less closely resembling itself. Though we may have no direct evidence of
the fact in each individual case, the knowledge derived from the
combined observations of an overwhelming number of analogous cases is of
such a positive character that we should entirely refuse to credit any
one who made the contrary assertion, and should feel satisfied that he
had been deluded by some error of observation. We cannot, indeed,
conceive of the sudden beginning of any such creatures, either from
nothing, from inorganic matter, or even from other animals or plants
totally unlike themselves.
To persons whose opportunities of observation of animal and plant life
are limited to a comparatively few kinds, existing under comparatively
similar circumstances, and which observations moreover only extend over
a comparatively limited period of time, it appears that in each kind of
animal or plant such as those just mentioned, individuals of various
succeeding generations present a very close resemblance to each other.
That they often vary a little cannot escape careful observation, but the
deviations from the common characters of the kind to be noticed by
persons whose range of vision is thus limited are not striking, and
usually appear not to pass beyond certain bounds. Hence arose the common
idea, natural enough under such circumstances, but which gradually
developed itself, not only into a scientific hypothesis, but even, it
would appear, almost into an article of religious belief, that the
different kinds or “species,” as they are technically called, of animals
and plants, had each its separate origin, its fixed limits of variation,
and could not under any circumstances become modified or changed into
any other form.
This idea became deeply rooted in the human mind, in consequence of the
very long period during which it prevailed, the horizon of observation
having remained practically stationary from the time man first began to
observe and record the phenomena of nature, until little more than a
century ago, when commenced that sudden expansion of knowledge of the
facts of the animal and vegetable world, which has been steadily
widening ever since. Now it is important to observe that it is strictly
_pari passu_ with the growth of knowledge of the facts, that the
theoretical views of nature have changed, and the older hypothesis of
species to which I have referred has gradually given way to a new and
different one.
The expansion of the special branches of knowledge affecting our views
upon this subject has taken place in many different directions, of which
I can here only indicate the most striking.
1. The discovery of enormous numbers of forms of life, the existence of
which was entirely unknown a hundred years ago. The increase of
knowledge in this respect is something inconceivable to those who have
not followed its progress. Not only has the number of well-defined
species known multiplied prodigiously, but infinite series of gradations
between what were formerly supposed to be distinct species are being
constantly brought to light. The difficulty of giving any satisfactory
definition of what is meant by the term “species” is increasingly felt
day by day by practical zoologists, as evidenced by the introduction of
such terms as “sub-species,” “permanent local variety,” etc., into
general use, and especially by the wide differences of opinion as to the
number or limits of the species included in any given group of animals
or plants among naturalists who have made such group their special
study.
2. Vast increase in the knowledge of the intimate structure of organic
bodies, both as revealed by ordinary dissection, and by microscopic
examination, a method of investigation only brought to perfection in
very recent years. By the knowledge thus acquired has been demonstrated
the unity of plan pervading, under diverse modifications, the different
members of each natural group of organisms, at one time attributed to
“conformity to type,” a so-called explanation which explained nothing,
but for which a _vera causa_ may be found in descent from a common
ancestor. Wonderful gradations in the perfection to which different
structures have attained in the progress of their adaptation to their
respective purposes have also been shown, and of still greater
importance and interest, the numerous cases of apparently useless or
rudimentary organs in both animals and plants, which were absolutely
unaccounted for under the older hypothesis.
3. The comparatively new study of the geographical distribution of
living things, which has only become possible since the prosecution of
the systematic and scientific explorations of the earth’s surface, which
have distinguished the present century. The results of this branch of
inquiry alone have been sufficient to convince many naturalists of the
unsoundness of the old view of the distinct origin of species, whether
created each in the region of the globe to which it is now confined, or,
as many still imagine, all in one spot, from which they have spread
themselves unchanged in form, colour, or other essential attributes to
their present abodes, however diverse in climate and other environments
or conditions of existence.
4. Lastly, though most important of all, must be mentioned the entirely
new science of palæolontology, opening up worlds of organic life before
unknown, also showing infinite gradations of structure, but mainly
important as increasing our horizon of observation to an extent not
previously dreamt of in the direction of time. Powers of observation
formerly limited to the brief space of a few generations are now
extended over ages, which the concurrent testimony of various branches
of knowledge, of astronomy, cosmogony, and geology, show are
immeasurable compared with any periods of which we hitherto had
cognisance. We are enabled to trace, and every year, as discovery
succeeds discovery, with increasing distinctness, numerous cases of
sequences of modification running through groups of animals in
successive periods of time, such as the gradual progress in the
development and perfection of the antlers of deer, from their entire
absence in the earliest known representatives of the type, through the
simple conical or bifurcated form, increasing in complexity as time
advanced to the magnificent many-branched appendages which adorn the
heads of some species of recent stags; such also as the progressive
modifications, so often described, beginning in the short-necked,
heavy-limbed, many-toed tapir-like animal of the Eocene period, and
ending in the graceful, long-necked, light-limbed, single-toed horse of
our own age, and numerous others which time will not allow me even to
mention.
It would be impossible here to trace the history of the effect of this
enormous influx of knowledge upon the doctrine of the separate origin
and fixed characters of species; to narrate the scattered efforts of
philosophical minds, discontented with the former views, but not yet
clearly seeing the light; to describe the slow and struggling growth of
the new views, amid difficulties arising from imperfections of knowledge
and the opposition of prejudice, or to apportion to each of those who by
their labours have contributed to the final result, his exact share in
bringing it about. How much, for instance, is due to the work and the
writings of our illustrious countryman, Darwin? and how much to those
who have preceded or followed him? All this forms an episode in the
history of the progress of human knowledge, which has been abundantly
chronicled elsewhere.
The result may, however, be briefly stated to be, that the opinion now
almost, if not quite, universal among skilled and thoughtful naturalists
of all countries, and whatever their beliefs upon other subjects, is
that the various forms of life which we see around us, and the
existence of which we know from their fossil remains, are the product,
not of independent creations, but of descent with gradual modification
from pre-existing forms. In short, the law of the natural descent of
individuals, of varieties, races, or breeds (which being within the
limits of the previous powers of observation, was already universally
admitted), has been extended to the still greater modifications
constituting what we call species, and consequently to the higher groups
called genera, families, and orders. The barrier fancied to exist
between so-called varieties and so-called species has broken down.
Any one commencing the study of the subject at the present time without
prejudice, and carefully investigating the evidence upon which to form
his conclusions, bearing in mind that he must look for his proofs, not
so much in direct experiments or absolute demonstrations, which from the
nature of the case are impossible, but in the convergence of the
indications furnished by the interpretations of multitudinous facts of
most diverse kinds, must find it extremely difficult to place himself in
the position of those who held the older view, so much more reasonable,
so much more in accordance with all that we know of the general
phenomena of nature, does this new one seem. In fact the _onus probandi_
now appears entirely to lie with those who make the assertion that
species have been separately created. Where, it may be asked, is the
shadow of a scientific proof that the first individual of any species
has come into being without pre-existing parents? Has any competent
observer at any time witnessed such an occurrence? The apparent advent
of a new species in geological history, a common event enough, has
certainly been cited as such. As well might the presence of a horse in a
field, with no sign of other animals of the same kind near it, be quoted
as evidence of the fallacy of the common view of the descent of
individuals. Ordinary observation tells us of the numerous causes which
may have isolated that horse from its parents and kindred. Geologists
know equally well how slight the chances of more than a stray individual
or fragment of an individual here and there being first preserved and
afterwards discovered to give any indication of the existence of the
race. Those who object to the new view complain sometimes of the
frequency with which its advocates take refuge, as they call it, in the
“imperfection of the geological record.” I think, on the contrary, the
difficulty is always to allow sufficiently for this imperfection. When
we contrast the present knowledge of palæolontology with what it was
fifty or even ten years ago--when we see by what mere accident as it
were, a railway driven through a new country, a quarry worked for
commercial purposes, a city newly fortified, so many of the most
important discoveries of extinct animals have been made--we must be
convinced that all arguments drawn from the absence of the required
links are utterly valueless. The study of palæolontology is as yet in
its merest infancy, the wonder is that it has already furnished so much,
not so little, corroboration of the doctrine of transmutation of
species.
Direct proof is, then, equally absent from both theories. For the old
view it may be said that it has been held for a very long time by
persons whose knowledge of the facts of nature which bear upon it was
extremely limited. On the other hand, the new view is continually
receiving more support as that knowledge increases, and furnishes a key
to a vast number of otherwise inexplicable facts in every branch of
natural history, in geological and geographical distribution, in the
habits of animals, in their development and growth, and especially in
their structure. I will take one instance from the last named--the
anatomy of the whale. How is it possible, upon any other supposition
than that it is the descendant of some land animal, with completely
developed limbs and teeth, which has become gradually modified to suit
an aquatic mode of existence, to explain the presence of the numerous
rudimentary, and to their present possessors absolutely useless,
structures found in its body. Amongst others, a complete set of teeth,
existing only in embryonic life, entirely disappearing even before
birth, and rudimentary hind legs, with their various bones, joints, and
muscles, of which no trace is seen externally. It may be asserted that
the whale was originally created so, as it was asserted, and long
maintained, that fossil shells and bones were originally created as such
in the rocks in which they are found. It took more than two centuries
of continuous and most acrimonious discussion to convince the world,
especially the theological world, that these were the actual remains of
animals which had once lived in a former period of the earth’s history.
Their evidence is now, however, universally admitted as supplying
knowledge of the changed conditions of the surface of the earth, and
with equal clearness do these rudimentary organs, hidden in the secret
recesses of the whale’s body, furnish, to those who inquire, indications
that the animal has passed through phases of existence unlike those in
which we now see it.
I do not for a moment assert that the new view explains everything that
we students of nature are longing to know, or that we do not everywhere
meet with obscure problems and perplexing difficulties, facts that we
cannot account for, and breaks in the chain of evidence. As to the
details and mode of operation of the secondary laws by which variation
and modification have been brought about, we are far from being in
accord. Happy for us that it is so, or our work would be at an end. I
only maintain that the transmutation view removes more difficulties,
requires fewer assumptions, and presents so much more consistency with
observed facts, than that which it seeks to supersede, and is,
therefore, so generally accepted, that there is no more probability of
its being abandoned, and the old doctrine of the fixity of species
revived, than that we should revert to the old astronomical theories
which placed the earth in the centre of the universe, and limited the
date of its creation to six ordinary days.
The question of the fixity or the transmutation of species is a purely
scientific one, only to be discussed and decided on scientific grounds.
To the naturalist, it is clearly one of extreme importance, as it gives
him for the first time a key to the interpretation of the phenomena with
which he has to deal. It may seem to many that a question like this is
entirely beside the business of a Church Congress, as it is one with
which only those expert in the ways of scientific investigation, and
deeply imbued with knowledge of scientific facts, could be called upon
to deal. This would certainly have been my view, if it had not been that
some who, from their capacities and education, should have been
onlookers in such a controversy, awaiting the issues of the conflict
while the lists are being fought out by the trained knights, have rushed
into the fray, and by their unskilful interposition have only confused
the issues, casting about dust instead of light. In the hope of clearing
away some of this dust the present discussion has been decided upon.
It is self-evident that a solid advance of any branch of knowledge must,
in some way or other, and to a greater or less degree, influence many
others, even those not directly connected with it, and therefore the
rapid simultaneous strides of so many branches of knowledge as may be
embraced under the term of “Recent Advances in Natural Science,” will be
very likely to have some bearing upon theological beliefs. Whether in
the direction of expanding, improving, purifying, elevating, or in the
direction of contracting, hardening, and destroying, depends not upon
those engaged in contributing to the advance of science, but upon those
whose special duty it is to show the bearing of these advances upon
hitherto received theological dogmas. The scientific questions
themselves may well be left to experts. If the new doctrines are not
true, there are plenty of keen critics among men of science ready to
sift the sound from the unsound. Error in scientific subjects has its
day, but it is certain not long to survive the ordeal, yearly increasing
in severity, to which it is subjected by those devoted to its
cultivation. On the other hand, the advances of truth, though they may
be retarded, will never be stopped by the opposition of those who are
incompetent by the nature of their education to deal with the evidence
on which it rests. There is no position so dangerous to religion as that
which binds it up essentially with this or that scientific doctrine,
with which it must either stand or fall. The history of the reception of
the greatest discoveries in Astronomy and Geology, the passionate
clinging to the exploded pseudo-scientific views on those subjects
supposed to be bound up with religious faith, the fierce denunciations
of the advocates of the then new, but now universally accepted ideas,
are well-worn subjects, and would not be alluded to but for the
repetition, almost literal repetition in some cases, of that reception
which has been accorded to the new views of biology.
Ought not the history of those discoveries and the controversies to
which they gave rise, to be both a warning and an encouragement? Those
who hoped and those who feared that faith would be destroyed by them,
have been equally mistaken; and is it not probable that the same result
will follow the great biological discoveries and controversies of the
present day?
In stating thus briefly what is the issue of these discoveries, as
generally understood and accepted by men of science, I have done all
that I promised, and must leave, in far more competent hands, the part
of the subject especially appropriate for discussion at this meeting. I
may, however, perhaps be allowed to put a few plain and simple
considerations before you, which may have some bearing upon the subject,
and which have no pretensions to novelty, though being often lost sight
of, their repetition may do no harm.
I said at the commencement of this paper that it has long been admitted
by all educated persons, whatever their religious faith may be, that
that very universal, but still most wonderful process, the commencement
and gradual development of a new individual of whatever living form,
whether plant, animal, or man, takes place according to definite and
regularly acting laws, without miraculous interposition. Further than
this, I believe that every one will admit that the production of the
various races or breeds of domestic animals is brought about by similar
means. We do not think it necessary to call in any special intervention
of creative power to produce a short-horned race of cattle, or to
account for the difference between a bull dog and a greyhound, a Dorking
and a Cochin-China fowl. The gradual modifications by which these races
were produced, having taken place under our own eyes as it were, we are
satisfied that they are the consequence of what we call natural laws,
modified and directed in these particular cases by man’s agency. We have
even gone farther, having long admitted, without the slightest fear of
producing a collision with religious faith, that variation has taken
place among animals in a wild state, producing local races of more or
less stable and permanent character, and brought about by the influence
of food, climate, and other surrounding circumstances.
The evidences of the Divine government of the world, and of the
Christian faith, have been sufficient for us, notwithstanding our
knowledge that the individual was created according to law, and that the
race or variety was also created according to law. In what way then can
they be affected by the knowledge that the somewhat greater
modifications, which we call species, were also created according to
law? The difficulties, which to some minds seem insuperable, remain
exactly as they were; the proofs, which to others are so convincing, are
entirely unaffected by this widening of scientific knowledge.
Even to what is to many the supreme difficulty of all, the origin of
man, the same considerations are applicable. Believe everything you will
about man in his highest intellectual and moral development, about the
nature, origin, existence, and destiny of the human soul; you have long
been able to reconcile all this with the knowledge of his individual
material origin according to law, in no whit different in principle from
that of the beasts of the field, passing through all the phases they go
through, and existing long before possessing, except potentially, any of
the special attributes of humanity. At what exact period and by what
means the great transformation takes place no one can tell. If the most
Godlike of men have passed through the stages which physiologists
recognise in human development without prejudice to the noblest,
highest, most divine part of their nature, why should not the race of
mankind, as a whole, have had a similar origin, followed by similar
progress and development, equally without prejudice to its present
condition and future destiny? Can it be of real consequence at the
present time, either to our faith or our practice, whether the first man
had such an extremely lowly beginning as the dust of the earth, in the
literal sense of the words, or whether he was formed through the
intervention of various progressive stages of animal life?
The reign of order and law in the government of the world has been so
far admitted that all these questions have really become questions of a
little more or a little less order and law. Science may well be left to
work out the details as it may. Science has thrown some light, little
enough at present, but ever increasing, and for which we should all be
thankful, upon the processes or methods by which the world in which we
dwell has been brought into its present condition. The wonder and
mystery of Creation remain as wonderful and mysterious as before. Of the
origin of the whole, science tells us nothing. It is still as impossible
as ever to conceive that such a world, governed by laws, the operations
of which have led to such mighty results, and are attended by such
future promise, could have originated without the intervention of some
power external to itself. If the succession of small miracles, formerly
supposed to regulate the operations of nature, no longer satisfies us,
have we not substituted for them one of immeasurable greatness and
grandeur?
X
A PRACTICAL LESSON FROM BIOLOGICAL STUDIES[29]