are needed to account for the character and disposition of the components
of the crust of the earth, that he says, broadly and boldly:--" ... There
is no part of the earth which has not had the same origin, so far as this
consists in that earth being collected at the bottom of the sea, and
afterwards produced, as land, along with masses of melted substances, by
the operation of mineral causes."[4]
[Footnote 4: _Ibid._. p. 371.]
But other influences were at work upon Hutton beside those of a mind
logical by nature, and scientific by sound training; and the peculiar
turn which his speculations took seems to me to be unintelligible, unless
these be taken into account. The arguments of the French astronomers and
mathematicians, which, at the end of the last century, were held to
demonstrate the existence of a compensating arrangement among the
celestial bodies, whereby all perturbations eventually reduced themselves
to oscillations on each side of a mean position, and the stability of the
solar system was secured, had evidently taken strong hold of Hutton's
mind.
In those oddly constructed periods which seem to have prejudiced many
persons against reading his works, but which are full of that peculiar,
if unattractive, eloquence which flows from mastery of the subject,
Hutton says:--
"We have now got to the end of our reasoning; we have no data further to
conclude immediately from that which actually is. But we have got enough;
we have the satisfaction to find, that in Nature there is wisdom, system,
and consistency. For having, in the natural history of this earth, seen a
succession of worlds, we may from this conclude that there is a system in
Nature; in like manner as, from seeing revolutions of the planets, it is
concluded, that there is a system by which they are intended to continue
those revolutions. But if the succession of worlds is established in the
system of nature, it is in vain to look for anything higher in the origin
of the earth. The result, therefore, of this physical inquiry is, that we
find no vestige of a beginning,--no prospect of an end."[5]
[Footnote 5: _Ibid._, vol. i. p. 200.]
Yet another influence worked strongly upon Hutton. Like most philosophers
of his age, he coquetted with those final causes which have been named
barren virgins, but which might be more fitly termed the _hetairoe_ of
philosophy, so constantly have they led men astray. The final cause of
the existence of the world is, for Hutton, the production of life and
intelligence.
"We have now considered the globe of this earth as a machine, constructed
upon chemical as well as mechanical principles, by which its different
parts are all adapted, in form, in quality, and in quantity, to a certain
end; an end attained with certainty or success; and an end from which we
may perceive wisdom, in contemplating the means employed.
"But is this world to be considered thus merely as a machine, to last no
longer than its parts retain their present position, their proper forms
and qualities? Or may it not be also considered as an organised body?
such as has a constitution in which the necessary decay of the machine is
naturally repaired, in the exertion of those productive powers by which
it had been formed.
"This is the view in which we are now to examine the globe; to see if
there be, in the constitution of this world, a reproductive operation, by
which a ruined constitution may be again repaired, and a duration or
stability thus procured to the machine, considered as a world sustaining
plants and animals."[6]
[Footnote 6: _Ibid._, vol. i. pp. 16, 17.]
Kirwan, and the other Philistines of the day, accused Hutton of declaring
that his theory implied that the world never had a beginning, and never
differed in condition from its present state. Nothing could be more
grossly unjust, as he expressly guards himself against any such
conclusion in the following terms:--
"But in thus tracing back the natural operations which have succeeded
each other, and mark to us the course of time past, we come to a period
in which we cannot see any farther. This, however, is not the beginning
of the operations which proceed in time and according to the wise economy
of this world; nor is it the establishing of that which, in the course of
time, had no beginning; it is only the limit of our retrospective view of
those operations which have come to pass in time, and have been conducted
by supreme intelligence."[7]
[Footnote 7: _Ibid._, vol. i. p. 223.]
I have spoken of Uniformitarianism as the doctrine of Hutton and of
Lyell. If I have quoted the older writer rather than the newer, it is
because his works are little known, and his claims on our veneration too
frequently forgotten, not because I desire to dim the fame of his eminent
successor. Few of the present generation of geologists have read
Playfair's "Illustrations," fewer still the original "Theory of the
Earth"; the more is the pity; but which of us has not thumbed every page
of the "Principles of Geology"? I think that he who writes fairly the
history of his own progress in geological thought, will not be able to
separate his debt to Hutton from his obligations to Lyell; and the
history of the progress of individual geologists is the history of
geology.
No one can doubt that the influence of uniformitarian views has been
enormous, and, in the main, most beneficial and favourable to the
progress of sound geology.
Nor can it be questioned that Uniformitarianism has even a stronger title
than Catastrophism to call itself the geological speculation of Britain,
or, if you will, British popular geology. For it is eminently a British
doctrine, and has even now made comparatively little progress on the
continent of Europe. Nevertheless, it seems to me to be open to serious
criticism upon one of its aspects.
I have shown how unjust was the insinuation that Hutton denied a
beginning to the world. But it would not be unjust to say that he
persistently in practice, shut his eyes to the existence of that prior
and different state of things which, in theory, he admitted; and, in this
aversion to look beyond the veil of stratified rocks, Lyell follows him.
Hutton and Lyell alike agree in their indisposition to carry their
speculations a step beyond the period recorded in the most ancient strata
now open to observation in the crust of the earth. This is, for Hutton,
"the point in which we cannot see any farther"; while Lyell tells us,--
"The astronomer may find good reasons for ascribing the earth's form to
the original fluidity of the mass, in times long antecedent to the first
introduction of living beings into the planet; but the geologist must be
content to regard the earliest monuments which it is his task to
interpret, as belonging to a period when the crust had already acquired
great solidity and thickness, probably as great as it now possesses, and
when volcanic rocks, not essentially differing from those now produced,
were formed from time to time, the intensity of volcanic heat being
neither greater nor less than it is now."[8]
[Footnote 8: _Principles of Geology_, vol. ii. p. 211.]
And again, "As geologists, we learn that it is not only the present
condition of the globe which has been suited to the accommodation of
myriads of living creatures, but that many former states also have been
adapted to the organisation and habits of prior races of beings. The
disposition of the seas, continents and islands, and the climates, have
varied; the species likewise have been changed; and yet they have all
been so modelled, on types analogous to those of existing plants and
animals, as to indicate, throughout, a perfect harmony of design and
unity of purpose. To assume that the evidence of the beginning, or end,
of so vast a scheme lies within the reach of our philosophical inquiries,
or even of our speculations, appears to be inconsistent with a just
estimate of the relations which subsist between the finite powers of man
and the attributes of an infinite and eternal Being."[9]
[Footnote 9: _Ibid._, vol. ii. p. 613.]
The limitations implied in these passages appear to me to constitute the
weakness and the logical defect of Uniformitarianism. No one will impute
blame to Hutton that, in face of the imperfect condition, in his day, of
those physical sciences which furnish the keys to the riddles of geology,
he should have thought it practical wisdom to limit his theory to an
attempt to account for "the present order of things"; but I am at a loss
to comprehend why, for all time, the geologist must be content to regard
the oldest fossiliferous rocks as the _ultima Thule_ of his science; or
what there is inconsistent with the relations between the finite and the
infinite mind, in the assumption, that we may discern somewhat of the
beginning, or of the end, of this speck in space we call our earth. The
finite mind is certainly competent to trace out the development of the
fowl within the egg; and I know not on what ground it should find more
difficulty in unravelling the complexities Of the development of the
earth. In fact, as Kant has well remarked,[10] the cosmical process is
really simpler than the biological.
[Footnote 10: "Man darf es sich also nicht befremden lassen, wenn ich
mich unterstehe zu sagen, dass eher die Bildung aller Himmelskörper, die
Ursache ihrer Bewegungen, kurz der Ursprung der gantzen gegenwärtigen
Verfassung des Weltbaues werden können eingesehen werden, ehe die
Erzeugung eines einzigen Krautes oder einer Raupe aus mechanischen
Gründen, deutlich und vollständig kund werden wird."--KANT'S _Sämmtliche
Werke_, Bd. i. p. 220.]
This attempt to limit, at a particular point, the progress of inductive
and deductive reasoning from the things which are, to those which were--
this faithlessness to its own logic, seems to me to have cost
Uniformitarianism the place, as the permanent form of geological
speculation, which it might otherwise have held.
It remains that I should put before you what I understand to be the third
phase of geological speculation--namely, EVOLUTIONISM.
I shall not make what I have to say on this head clear, unless I diverge,
or seem to diverge, for a while, from the direct path of my discourse, so
far as to explain what I take to be the scope of geology itself. I
conceive geology to be the history of the earth, in precisely the same
sense as biology is the history of living beings; and I trust you will
not think that I am overpowered by the influence of a dominant pursuit if
I say that I trace a close analogy between these two histories.
If I study a living being, under what heads does the knowledge I obtain
fall? I can learn its structure, or what we call its ANATOMY; and its
DEVELOPMENT, or the series of changes which it passes through to acquire
its complete structure. Then I find that the living being has certain
powers resulting from its own activities, and the interaction of these
with the activities of other things--the knowledge of which is
PHYSIOLOGY. Beyond this the living being has a position in space and
time, which is its DISTRIBUTION. All these form the body of ascertainable
facts which constitute the _status quo_ of the living creature. But these
facts have their causes; and the ascertainment of these causes is the
doctrine of AETIOLOGY.
If we consider what is knowable about the earth, we shall find that such
earth-knowledge--if I may so translate the word geology--falls into the
same categories.
What is termed stratigraphical geology is neither more nor less than the
anatomy of the earth; and the history of the succession of the formations
is the history of a succession of such anatomies, or corresponds with
development, as distinct from generation.
The internal heat of the earth, the elevation and depression of its
crust, its belchings forth of vapours, ashes, and lava, are its
activities, in as strict a sense as are warmth and the movements and
products of respiration the activities of an animal. The phenomena of the
seasons, of the trade winds, of the Gulf-stream, are as much the results
of the reaction between these inner activities and outward forces, as are
the budding of the leaves in spring and their falling in autumn the
effects of the interaction between the organisation of a plant and the
solar light and heat. And, as the study of the activities of the living
being is called its physiology, so are these phenomena the subject-matter
of an analogous telluric physiology, to which we sometimes give the name
of meteorology, sometimes that of physical geography, sometimes that of
geology. Again, the earth has a place in space and in time, and relations
to other bodies in both these respects, which constitute its
distribution. This subject is usually left to the astronomer; but a
knowledge of its broad outlines seems to me to be an essential
constituent of the stock of geological ideas.
All that can be ascertained concerning the structure, succession of
conditions, actions, and position in space of the earth, is the matter of
fact of its natural history. But, as in biology, there remains the matter
of reasoning from these facts to their causes, which is just as much
science as the other, and indeed more; and this constitutes geological
aetiology.
Having regard to this general scheme of geological knowledge and thought,
it is obvious that geological speculation may be, so to speak, anatomical
and developmental speculation, so far as it relates to points of
stratigraphical arrangement which are out of reach of direct observation;
or, it may be physiological speculation so far as it relates to
undetermined problems relative to the activities of the earth; or, it may
be distributional speculation, if it deals with modifications of the
earth's place in space; or, finally, it will be aetiological speculation
if it attempts to deduce the history of the world, as a whole, from the
known properties of the matter of the earth, in the conditions in which
the earth has been placed.
For the purposes of the present discourse I may take this last to be what
is meant by "geological speculation."
Now Uniformitarianism, as we have seen, tends to ignore geological
speculation in this sense altogether.
The one point the catastrophists and the uniformitarians agreed upon,
when this Society was founded, was to ignore it. And you will find, if
you look back into our records, that our revered fathers in geology
plumed themselves a good deal upon the practical sense and wisdom of this
proceeding. As a temporary measure, I do not presume to challenge its
wisdom; but in all organised bodies temporary changes are apt to produce
permanent effects; and as time has slipped by, altering all the
conditions which may have made such mortification of the scientific flesh
desirable, I think the effect of the stream of cold water which has
steadily flowed over geological speculation within these walls has been
of doubtful beneficence.
The sort of geological speculation to which I am now referring
(geological aetiology, in short) was created, as a science, by that famous
philosopher Immanuel Kant, when, in 1775, he wrote his "General Natural
History and Theory of the Celestial Bodies; or an Attempt to account for
the Constitutional and the Mechanical Origin of the Universe upon
Newtonian principles."[11]
[Footnote 11: Grant (_History of Physical Astronomy_, p. 574) makes but
the briefest reference to Kant.]
In this very remarkable but seemingly little-known treatise,[12] Kant
expounds a complete cosmogony, in the shape of a theory of the causes
which have led to the development of the universe from diffused atoms of
matter endowed with simple attractive and repulsive forces.
[Footnote 12: "Allgemeine Naturgeschichte und Theorie des Himmels; oder
Versuch von der Verfassung und dem mechanischen Ursprunge des ganzen
Weltgebäudes nach Newton'schen Grundsatzen abgehandelt."--KANT'S
_Sämmtliche Werke_, Bd. i. p. 207.]
"Give me matter," says Kant, "and I will build the world;" and he
proceeds to deduce from the simple data from which he starts, a doctrine
in all essential respects similar to the well-known "Nebular Hypothesis"
of Laplace.[13] He accounts for the relation of the masses and the
densities of the planets to their distances from the sun, for the
eccentricities of their orbits, for their rotations, for their
satellites, for the general agreement in the direction of rotation among
the celestial bodies, for Saturn's ring, and for the zodiacal light. He
finds in each system of worlds, indications that the attractive force of
the central mass will eventually destroy its organisation, by
concentrating upon itself the matter of the whole system; but, as the
result of this concentration, he argues for the development of an amount
of heat which will dissipate the mass once more into a molecular chaos
such as that in which it began.
[Footnote 13: _Système du Monde_, tome ii. chap. 6.]
Kant pictures to himself the universe as once an infinite expansion of
formless and diffused matter. At one point of this he supposes a single
centre of attraction set up; and, by strict deductions from admitted
dynamical principles, shows how this must result in the development of a
prodigious central body, surrounded by systems of solar and planetary
worlds in all stages of development. In vivid language he depicts the
great world-maelstrom, widening the margins of its prodigious eddy in the
slow progress of millions of ages, gradually reclaiming more and more of
the molecular waste, and converting chaos into cosmos. But what is gained
at the margin is lost in the centre; the attractions of the central
systems bring their constituents together, which then, by the heat
evolved, are converted once more into molecular chaos. Thus the worlds
that are, lie between the ruins of the worlds that have been, and the
chaotic materials of the worlds that shall be; and in spite of all waste
and destruction, Cosmos is extending his borders at the expense of Chaos.
Kant's further application of his views to the earth itself is to be
found in his "Treatise on Physical Geography"[14] (a term under which the
then unknown science of geology was included), a subject which he had
studied with very great care and on which he lectured for many years. The
fourth section of the first part of this Treatise is called "History of
the great Changes which the Earth has formerly undergone and is still
undergoing," and is, in fact, a brief and pregnant essay upon the
principles of geology. Kant gives an account first "of the gradual
changes which are now taking place" under the heads of such as are caused
by earthquakes, such as are brought about by rain and rivers, such as are
effected by the sea, such as are produced by winds and frost; and,
finally, such as result from the operations of man.
[Footnote 14: Kant's _Sämmtliche Werke_, Bd. viii. p. 145.]
The second part is devoted to the "Memorials of the Changes which the
Earth has undergone in remote Antiquity." These are enumerated as:--A.
Proofs that the sea formerly covered the whole earth. B. Proofs that the
sea has often been changed into dry land and then again into sea. C. A
discussion of the various theories of the earth put forward by
Scheuchzer, Moro, Bonnet, Woodward, White, Leibnitz, Linnaeus, and Buffon.
The third part contains an "Attempt to give a sound explanation of the
ancient history of the earth."
I suppose that it would be very easy to pick holes in the details of
Kant's speculations, whether cosmological, or specially telluric, in
their application. But for all that, he seems to me to have been the
first person to frame a complete system of geological speculation by
founding the doctrine of evolution.
With as much truth as Hutton, Kant could say, "I take things just as I
find them at present, and, from these, I reason with regard to that which
must have been." Like Hutton, he is never tired of pointing out that "in
Nature there is wisdom, system, and consistency." And, as in these great
principles, so in believing that the cosmos has a reproductive operation
"by which a ruined constitution may be repaired," he forestalls Hutton;
while, on the other hand, Kant is true to science. He knows no bounds to
geological speculation but those of the intellect. He reasons back to a
beginning of the present state of things; he admits the possibility of an
end.
I have said that the three schools of geological speculation which I have
termed Catastrophism, Uniformitarianism, and Evolutionism, are commonly
supposed to be antagonistic to one another; and I presume it will have
become obvious that in my belief, the last is destined to swallow up the
other two. But it is proper to remark that each of the latter has kept
alive the tradition of precious truths.
CATASTROPHISM has insisted upon the existence of a practically unlimited
bank of force, on which the theorist might draw; and it has cherished the
idea of the development of the earth from a state in which its form, and
the forces which it exerted, were very different from those we now know.
That such difference of form and power once existed is a necessary part
of the doctrine of evolution.
UNIFORMITARIANISM, on the other hand, has with equal justice insisted
upon a practically unlimited bank of time, ready to discount any quantity
of hypothetical paper. It has kept before our eyes the power of the
infinitely little, time being granted, and has compelled us to exhaust
known causes, before flying to the unknown.
To my mind there appears to be no sort of necessary theoretical
antagonism between Catastrophism and Uniformitarianism. On the contrary,
it is very conceivable that catastrophes may be part and parcel of
uniformity. Let me illustrate my case by analogy. The working of a clock
is a model of uniform action; good time-keeping means uniformity of
action. But the striking of the clock is essentially a catastrophe; the
hammer might be made to blow up a barrel of gunpowder, or turn on a
deluge of water; and, by proper arrangement, the clock, instead of
marking the hours, might strike at all sorts of irregular periods, never
twice alike, in the intervals, force, or number of its blows.
Nevertheless, all these irregular, and apparently lawless, catastrophes
would be the result of an absolutely uniformitarian action; and we might
have two schools of clock-theorists, one studying the hammer and the
other the pendulum.
Still less is there any necessary antagonists between either of these
doctrines and that of Evolution, which embraces all that is sound in both
Catastrophism and Uniformitarianism, while it rejects the arbitrary
assumptions of the one and the, as arbitrary, limitations of the other.
Nor is the value of the doctrine of Evolution to the philosophic thinker
diminished by the fact that it applies the same method to the living and
the not-living world; and embraces, in one stupendous analogy, the growth
of a solar system from molecular chaos, the shaping of the earth from the
nebulous cub-hood of its youth, through innumerable changes and
immeasurable ages, to its present form; and the development of a living
being from the shapeless mass of protoplasm we term a germ.
I do not know whether Evolutionism can claim that amount of currency
which would entitle it to be called British popular geology; but, more or
less vaguely, it is assuredly present in the minds of most geologists.
Such being the three phases of geological speculation, we are now in
position to inquire which of these it is that Sir William Thomson calls
upon us to reform in the passages which I have cited.