TRANSCRIBER’S NOTE
Italic text is denoted by _underscores_.
Footnote anchors are denoted by [number], and the footnotes have been
placed at the end of the book.
Some minor changes to the text are noted at the end of the book.
BRIDGEWATER TREATISES.
CAREY, LEA & BLANCHARD
HAVE PUBLISHED,
ASTRONOMY AND GENERAL PHYSICS, considered with reference to Natural
Theology, by the Rev. WILLIAM WHEWELL, M. A., Fellow and Tutor
of Trinity College, Cambridge; being the _Third Part_ of the
Bridgewater Treatises on the Power, Wisdom, and Goodness of God, as
manifested in the Creation.
The series of Treatises, of which the present is one, is
published under the following circumstances:--
The Right Honourable and Rev. FRANCIS HENRY, Earl of Bridgewater,
died in the month of February, 1825; he directed certain
trustees therein named, to invest in the public funds, the sum
of eight thousand pounds sterling; this sum, with the accruing
dividends thereon, to be held at the disposal of the President,
for the time being, of the Royal Society of London, to be paid
to the person or persons nominated by him. The Testator farther
directed, that the person or persons selected by the said
President, should be appointed to write, print and publish one
thousand copies of a work, on the Power, Wisdom, and Goodness
of God, as manifested in the Creation; illustrating such work,
by all reasonable arguments, as, for instance, the variety and
formation of God’s creatures in the Animal, Vegetable, and
Mineral Kingdoms; the effect of digestion, and, thereby, of
conversion; the construction of the hand of man, and an infinite
variety of other arguments; as also by discoveries, ancient and
modern, in arts, sciences, and the whole extent of literature.
He desired, moreover, that the profits arising from the sale of
the works so published, should be paid to the authors of the
works.
The late President of the Royal Society, DAVIES GILBERT, Esq.,
requested the assistance of his Grace, the Archbishop of
Canterbury, and of the Bishop of London, in determining upon
the best mode of carrying into effect, the intentions of the
Testator. Acting with their advice, and with the concurrence of
a nobleman immediately connected with the deceased, Mr. Davies
Gilbert appointed the following eight gentlemen to write separate
Treatises in the different branches of the subjects here stated:--
I. The Adaptation of External Nature to the Moral and
Intellectual Constitution of Man, by the Rev. THOMAS CHALMERS, D.
D., Professor of Divinity in the University of Edinburgh.
II. The Adaptation of External Nature to the Physical Condition
of Man, by JOHN KIDD, M. D., F. R. S., Regius Professor of
Medicine in the University of Oxford.
III. Astronomy and General Physics, considered with reference to
Natural Theology, by the Rev. WILLIAM WHEWELL, M. A., F. R. S.,
Fellow of Trinity College, Cambridge.
IV. The Hand: its Mechanism and Vital Endowments as evincing
Design, by Sir CHARLES BELL, K. H., F. R. S.
V. Animal and Vegetable Physiology, by PETER MARK ROGET, M. D.,
Fellow of and Secretary to the Royal Society.
VI. Geology and Mineralogy, by the Rev. WILLIAM BUCKLAND, D. D.,
F. R. S., Canon of Christ Church, and Professor of Geology in the
University of Oxford.
VII. The History, Habits, and Instincts of Animals, by the Rev.
WILLIAM KIRBY, M. A., F. R. S.
VIII. Chemistry, Meteorology, and the Function of Digestion, by
WILLIAM PROUT, M. D., F. R. S.
_The whole of these Treatises are nearly finished, and will be
put to press as soon as received, and published in a cheap and
handsome form._
THE PRINCIPLES OF CHRISTIAN PHILOSOPHY; containing the Doctrines,
Duties, Admonitions, and Consolations of the Christian Religion, by
JOHN BURNS, M. D., F. R. S. From the fourth London edition. In the
press.
CONVERSATIONS WITH LORD BYRON ON THE SUBJECT OF RELIGION. By J.
KENNEDY, M. D. 12mo.
GLEANINGS IN NATURAL HISTORY, WITH LOCAL RECOLLECTIONS. By EDWARD
JESSE, Esq. To which are added, Maxims and Hints for Anglers. From
the second London edition, in one volume, being a Companion to the
Journal of a Naturalist.
We have occasionally selected a paragraph from a very pretty
volume, by Mr. Jesse, published under the above title. The
author lives in the neighbourhood of Kew, and like Mr. White
of Selborne,--who made a small village of Hampshire one of the
most interesting spots to the lover of nature, by his ample
descriptions of the natural objects which he saw around him,--Mr.
Jesse has rendered his walks a vehicle for much instruction and
amusement to himself and to others. He principally confines
his attention to zoology--the most generally attractive of the
departments of natural history; and he looks upon the animal
world with so much practical wisdom, being disposed to be happy
himself, and to see every creature around him happy, that there
are few persons who will not read his slight sketches with
improvement to their hearts and understandings.--_Penny Magazine._
THE MECHANISM OF THE HEAVENS. By Mrs. SOMERVILLE. In 18mo.
Is it asking too much of Mrs. Somerville to express a hope that
she will allow this beautiful preliminary Dissertation to be
printed separately for the delight and instruction of thousands
of readers, young and old, who cannot understand, or are too
indolent to apply themselves to the more elaborate parts of the
work? If she will do this, we hereby promise to exert our best
endeavours to make its merits known.--_Literary Gazette._
SALMONIA; OR, DAYS OF FLY FISHING. By Sir H. DAVY.
We are surprised in meeting with an American reprint of this
delightful volume, that a work so universally popular has not
been before republished in this country.--_N. Y. American._
One of the most delightful labours of leisure ever seen; not a
few of the most beautiful phenomena of nature are here lucidly
explained.--_Gent. Magazine._
THE NATURAL HISTORY OF SELBORNE. By the late Rev. GILBERT WHITE,
A. M., Fellow of the Oriel College, Oxford; with additions by Sir
WILLIAM JARDINE, Bart. F. R. S., E. F. L. S., M. W. S., author of
“Illustrations of Ornithology.”
White’s History of Selborne, the most fascinating piece of rural
writing and sound English philosophy that has ever issued from
the press.--_Athenæum._
JOURNAL OF A NATURALIST. With Plates.
----Plants, trees, and stones we note;
Birds, insects, beasts and rural things.
We again most strongly recommend this little unpretending volume
to the attention of every lover of nature, and more particularly
of our country readers. It will induce them, we are sure, to
examine more closely than they have been accustomed to do, into
the objects of animated nature, and such examination will prove
one of the most innocent, and the most satisfactory sources of
gratification and amusement. It is a book that ought to find its
way into every rural drawing-room in the kingdom, and one that
may safely be placed in every lady’s boudoir, be her rank and
station in life what they may.--_Quart. Review_, No. LXXVIII.
This is a most delightful book on the most delightful of all
studies. We are acquainted with no previous work which bears
any resemblance to this, except “White’s History of Selborne,”
the most fascinating piece of rural writing and sound English
philosophy that ever issued from the press.--_Athenæum._
THE FAMILY CABINET ATLAS, constructed upon an original plan: being
a Companion to the Encyclopædia Americana, Cabinet Cyclopædia,
Family Library, Cabinet Library, &c.
[This Atlas comprises, in a volume of the Family Library size,
nearly one hundred Maps and Tables, which present equal to _fifty
thousand names of places_; a body of information three times as
extensive as that supplied by the generality of _Quarto Atlases_.]
This beautiful and most useful little volume, says the Literary
Gazette, is a perfect picture of elegance, containing a vast sum
of geographical information. A more instructive little present,
or a gift better calculated to be long preserved and often
referred to, could not be offered to favoured youth of either
sex. Its cheapness, we must add, is another recommendation; for,
although this elegant publication contains one hundred beautiful
engravings, it is issued at a price that can be no obstacle to
its being procured by every parent and friend to youth.
This Atlas far surpasses any thing of the kind which we have
seen, and is made to suit the popular libraries which Dr.
Lardner and Mr. Murray are now sending into every family in the
empire.--_Monthly Review._
Its very ingenious method of arrangement secures to the
geographical student the information for which hitherto
he has been obliged to resort to works of the largest
dimensions.--_Athenæum._
THE RECTORY OF VALEHEAD. By the Rev. ROBERT WILSON EVANS, M. A.
Universally and cordially do we recommend this delightful volume.
Impressed with the genuine spirit of Christianity; a diary, as it
were, of the feelings, hopes, and sorrows of a family,--it comes
home to all, either in sympathy or example. It is a beautiful
picture of a religious household, influencing to excellence all
within its sphere. We believe no person could read this work, and
not be better for its pious touching lessons.--_Literary Gaz._
We fearlessly pronounce this delightful little volume to be
not only one of the most faultless, but every way valuable
works it has ever fallen to our lot to recommend to public
perusal.--_Stamford Herald._
The Rectory of Valehead is a beautiful model of domestic life
in the Christian home of a well-regulated family, and combines
literary amusement with the most refined and intellectual
improvement.--_Scotsman._
A GENERAL VIEW OF THE PROGRESS OF ETHICAL PHILOSOPHY, chiefly
during the Seventeenth and Eighteenth Centuries. By Sir JAMES
MACKINTOSH, M. P. In 8vo.
The best offspring of the pen of an author who in philosophical
spirit, knowledge and reflection, richness of moral sentiment,
and elegance of style, has altogether no superior--perhaps no
equal--among his contemporaries. Some time ago we made copious
extracts from the beautiful work. We could not recommend the
whole too earnestly.--_National Gazette._
THE BOOK OF THE SEASONS; OR THE CALENDAR OF NATURE. By WILLIAM
HOWITT. In one volume, 12mo.
THE BRIDGEWATER TREATISES
ON THE POWER, WISDOM, AND GOODNESS OF GOD
AS MANIFESTED IN THE CREATION.
TREATISE III.
ON ASTRONOMY AND GENERAL PHYSICS.
BY THE REV. W. WHEWELL.
ET HÆC DE DEO, DE QUO UTIQUE EX PHÆNOMENIS DISSERERE AD
PHILOSOPHIAM NATURALEM PERTINET.
NEWTON, CONCLUSION OF THE PRINCIPIA.
ASTRONOMY AND GENERAL PHYSICS
CONSIDERED WITH REFERENCE TO
NATURAL THEOLOGY.
BY THE
REV. WILLIAM WHEWELL, M. A.
FELLOW AND TUTOR OF TRINITY COLLEGE,
CAMBRIDGE.
Philadelphia:
CAREY, LEA & BLANCHARD,
CHESTNUT STREET.
1833.
TO THE
RIGHT HONOURABLE AND RIGHT REVEREND
CHARLES JAMES,
LORD BISHOP OF LONDON.
MY LORD--
I owe it to you that I was selected for the task attempted in the
following pages, a distinction which I feel to be honourable;
and on this account alone I should have a peculiar pleasure in
dedicating the work to your lordship. I do so with additional
gratification on another account: the Treatise has been written
within the walls of the College of which your lordship was formerly
a resident member, and its merits, if it have any, are mainly
due to the spirit and habits of the place. The society is always
pleased and proud to recollect that a person of the eminent talents
and high character of your lordship is one of its members; and I
am persuaded that any effort in the cause of letters and religion
coming from that quarter, will have for you an interest beyond what
it would otherwise possess.
The subject proposed to me was limited: my prescribed object is to
lead the friends of religion to look with confidence and pleasure
on the progress of the physical sciences, by showing how admirably
every advance in our knowledge of the universe harmonizes with
the belief of a most wise and good God. To do this effectually
may be, I trust, a useful labour. Yet, I feel most deeply, what
I would take this occasion to express, that this, and all that
the speculator concerning Natural Theology can do, is utterly
insufficient for the great ends of Religion; namely, for the
purpose of reforming men’s lives, of purifying and elevating their
characters, of preparing them for a more exalted state of being. It
is the need of something fitted to do this, which gives to religion
its vast and incomparable importance; and this can, I well know, be
achieved only by that Revealed Religion of which we are ministers,
but on which the plan of the present work did not allow me to dwell.
That Divine Providence may prosper the labours of your lordship,
and of all who are joined with you in the task of maintaining and
promoting _this_ Religion, is, my lord, the earnest wish and prayer
of
Your very faithful
And much obliged servant,
WILLIAM WHEWELL.
Trinity College, Cambridge,
Feb. 25, 1833.
NOTICE.
The series of Treatises, of which the present is one, is published
under the following circumstances:
The RIGHT HONOURABLE and REVEREND FRANCIS HENRY, EARL OF
BRIDGEWATER, died in the month of February, 1829; and by his last
Will and Testament, bearing date the 25th of February, 1825, he
directed certain Trustees therein named to invest in the public
funds the sum of Eight thousand pounds sterling; this sum, with
the accruing dividends thereon, to be held at the disposal of the
President, for the time being, of the Royal Society of London, to
be paid to the person or persons nominated by him. The Testator
further directed, that the person or persons selected by the said
President should be appointed to write, print, and publish one
thousand copies of a work _On the Power, Wisdom, and Goodness of
God, as manifested in the Creation; illustrating such work by all
reasonable arguments, as for instance the variety and formation
of God’s creatures in the animal, vegetable, and mineral
kingdoms; the effect of digestion, and thereby of conversion;
the construction of the hand of man, and an infinite variety of
other arguments; as also by discoveries ancient and modern, in
arts, sciences, and the whole extent of literature_. He desired,
moreover, that the profits arising from the sale of the works so
published should be paid to the authors of the works.
The late President of the Royal Society, Davies Gilbert,
Esq. requested the assistance of his Grace the Archbishop of
Canterbury and of the Bishop of London, in determining upon
the best mode of carrying into effect the intentions of the
Testator. Acting with their advice, and with the concurrence of
a nobleman immediately connected with the deceased, Mr. Davies
Gilbert appointed the following eight gentlemen to write separate
Treatises on the different branches of the subject as here stated:
THE REV. THOMAS CHALMERS, D. D.
Professor of Divinity in the University of Edinburgh.
ON THE ADAPTATION OF EXTERNAL NATURE TO THE MORAL AND
INTELLECTUAL CONSTITUTION OF MAN.
JOHN KID, M. D. F. R. S.
Regius Professor of Medicine in the University of Oxford.
ON THE ADAPTATION OF EXTERNAL NATURE TO THE PHYSICAL
CONDITION OF MAN.
THE REV. WILLIAM WHEWELL, M. A. F. R. S.
Fellow of Trinity College, Cambridge.
ON ASTRONOMY AND GENERAL PHYSICS.
SIR CHARLES BELL, K. H. F. R. S,
THE HAND: ITS MECHANISM AND VITAL ENDOWMENTS AS EVINCING
DESIGN.
PETER MARK ROGET, M. D.
Fellow of and Secretary to the Royal Society.
ON ANIMAL AND VEGETABLE PHYSIOLOGY.
THE REV. WILLIAM BUCKLAND, D. D. F. R. S.
Canon of Christ Church, and Professor of Geology in the University of Oxford.
ON GEOLOGY AND MINERALOGY.
THE REV. WILLIAM KIRBY, M. A. F. R. S.
ON THE HISTORY, HABITS, AND INSTINCTS OF ANIMALS.
WILLIAM PROUT, M. D. F. R. S.
ON CHEMISTRY, METEOROLOGY, AND THE FUNCTION OF DIGESTION.
HIS ROYAL HIGHNESS THE DUKE OF SUSSEX, President of the Royal
Society, having desired that no unnecessary delay should take
place in the publication of the above mentioned treatises, they
will appear at short intervals, as they are ready for publication.
CONTENTS.
[Within the last year or two, several works have been published in
this country on subjects more or less closely approaching to that
here treated. It may, therefore, be not superfluous to say that the
author of the following pages believes that he has not borrowed
any of his views or illustrations from recent English writers on
Natural Theology.]
Page.
INTRODUCTION.
CHAPTER I. Object of the Present Treatise 13
II. On Laws of Nature 17
III. Mutual Adaptation of Laws of Nature 20
IV. Division of the Subject 23
BOOK I. TERRESTRIAL ADAPTATIONS 25
CHAPTER I. The Length of the Year 28
II. The Length of the Day 37
III. The Mass of the Earth 43
IV. The Magnitude of the Ocean 50
V. The Magnitude of the Atmosphere 51
VI. The Constancy and Variety of Climates 52
VII. The Variety of Organization corresponding
to the Variety of Climate 57
VIII. The Constituents of Climate 66
The Laws of Heat with respect to the Earth 67
IX. The Laws of Heat with respect to Water 70
X. The Laws of Heat with respect to Air 81
XI. The Laws of Electricity 91
XII. The Laws of Magnetism 93
XIII. The Properties of Light with regard to
Vegetation 94
XIV. Sound 96
XV. The Atmosphere 102
XVI. Light 104
XVII. The Ether 111
XVIII. Recapitulation 113
BOOK II. COSMICAL ARRANGEMENTS 119
CHAPTER I. The Structure of the Solar System 121
II. The Circular Orbits of the Planets round the Sun 123
III. The Stability of the Solar System 127
IV. The Sun in the Centre 134
V. The Satellites 137
VI. The Stability of the Ocean 140
VII. The Nebular Hypothesis 143
VIII. The Existence of a Resisting Medium in the
Solar System 150
IX. Mechanical Laws 163
X. The Law of Gravitation 166
XI. The Laws of Motion 178
XII. Friction 183
BOOK III. RELIGIOUS VIEWS 193
CHAPTER I. The Creator of the Physical World is the
Governor of the Moral World 195
II. On the Vastness of the Universe 205
III. On Man’s Place in the Universe 212
IV. On the Impression produced by the Contemplation
of Laws of Nature; or, on the Conviction
that Law implies Mind 223
V. On Inductive Habits; or, on the impression
produced on Men’s Minds by discovering
Laws of Nature 230
VI. On Deductive Habits; or, on the Impression
produced on Men’s Minds by tracing
the Consequences of ascertained Laws 243
VII. On Final Causes 257
VIII. On the Physical Agency of the Deity 267
IX. On the Impression produced by considering
the Nature and Prospects of Science;
or, on the Impossibility of the Progress
of our Knowledge ever enabling us to
comprehend the Nature of the Deity 273
ON
ASTRONOMY
AND
GENERAL PHYSICS.
INTRODUCTION.
CHAPTER I.
_Object of the Present Treatise._
The examination of the material world brings before us a number
of things and relations of things which suggest to most minds
the belief of a creating and presiding Intelligence. And this
impression, which arises with the most vague and superficial
consideration of the objects by which we are surrounded, is, we
conceive, confirmed and expanded by a more exact and profound study
of external nature. Many works have been written at different
times with the view of showing how our knowledge of the elements
and their operation, of plants and animals and their construction,
may serve to nourish and unfold our idea of a Creator and Governor
of the world. But though this is the case, a new work on the same
subject may still have its use. Our views of the Creator and
Governor of the world, as collected from or combined with our
views of the world itself, undergo modifications, as we are led by
new discoveries, new generalizations, to regard nature in a new
light. The conceptions concerning the Deity, his mode of effecting
his purposes, the scheme of his government, which are suggested
by one stage of our knowledge of natural objects and operations,
may become manifestly imperfect or incongruous, if adhered to and
applied at a later period, when our acquaintance with the immediate
causes of natural events has been greatly extended. On this account
it may be interesting, after such an advance, to show how the views
of the creation, preservation, and government of the universe,
which natural science opens to us, harmonize with our belief in
a Creator, Governor, and Preserver of the world. To do this with
respect to certain departments of Natural Philosophy is the object
of the following pages; and the author will deem himself fortunate,
if he succeeds in removing any of the difficulties and obscurities
which prevail in men’s minds, from the want of a clear mutual
understanding between the religious and the scientific speculator.
It is needless here to remark the necessarily imperfect and scanty
character of Natural Religion; for most persons will allow that,
however imperfect may be the knowledge of a Supreme Intelligence
which we gather from the contemplation of the natural world, it
is still of most essential use and value. And our purpose on this
occasion is, not to show that Natural Theology is a perfect and
satisfactory scheme, but to bring up our Natural Theology to the
point of view in which it may be contemplated by the aid of our
Natural Philosophy.
Now the peculiar point of view which at present belongs to Natural
Philosophy, and especially to the departments of it which have been
most successfully cultivated, is, that nature, so far as it is an
object of scientific research, is a collection of facts governed by
_laws_: our knowledge of nature is our knowledge of laws; of laws
of operation and connexion, of laws of succession and co-existence,
among the various elements and appearances around us. And it must
therefore here be our aim to show how this view of the universe
falls in with our conception of the Divine Author, by whom we hold
the universe to be made and governed.
_Nature acts by general laws_; that is, the occurrences of the
world in which we find ourselves, result from causes which operate
according to fixed and constant rules. The succession of days,
and seasons, and years, is produced by the motions of the earth;
and these again are governed by the attraction of the sun, a
force which acts with undeviating steadiness and regularity. The
changes of winds and skies, seemingly so capricious and casual,
are produced by the operation of the sun’s heat upon air and
moisture, land and sea; and though in this case we cannot trace
the particular events to their general causes, as we can trace
the motions of the sun and moon, no philosophical mind will doubt
the generality and fixity of the rules by which these causes act.
The variety of the effects takes place, because the circumstances
in different cases vary; and not because the action of material
causes leaves anything to chance in the result. And again, though
the vital movements which go on in the frame of vegetables and
animals depend on agencies still less known, and probably still
more complex, than those which rule the weather, each of the powers
on which such movements depend has its peculiar laws of action,
and these are as universal and as invariable as the law by which a
stone falls to the earth when not supported.
The world then is governed by general laws; and in order to
collect from the world itself a judgment concerning the nature
and character of its government, we must consider the import and
tendency of such laws, so far as they come under our knowledge. If
there be, in the administration of the universe, intelligence and
benevolence, superintendence and foresight, grounds for love and
hope, such qualities may be expected to appear in the constitution
and combination of those fundamental regulations by which the
course of nature is brought about, and made to be what it is.
If a man were, by some extraordinary event, to find himself in a
remote and unknown country, so entirely strange to him that he
did not know whether there existed in it any law or government at
all; he might in no long time ascertain whether the inhabitants
were controlled by any superintending authority; and with a little
attention he might determine also whether such authority were
exercised with a prudent care for the happiness and well-being
of its subjects, or without any regard and fitness to such ends;
whether the country were governed by laws at all, and whether the
laws were good. And according to the laws which he thus found
prevailing, he would judge of the sagacity, and the purposes of the
legislative power.
By observing the laws of the material universe and their operation,
we may hope, in a somewhat similar manner, to be able to direct
our judgment concerning the government of the universe: concerning
the mode in which the elements are regulated and controlled, their
effects combined and balanced. And the general tendency of the
results thus produced may discover to us something of the character
of the power which has legislated for the material world.
We are not to push too far the analogy thus suggested. There is
undoubtedly a wide difference between the circumstances of man
legislating for man, and God legislating for matter. Still we
shall, it will appear, find abundant reason to admire the wisdom
and the goodness which have established _the Laws of Nature_,
however rigorously we may scrutinize the import of this expression.
CHAPTER II.
_On Laws of Nature._
When we speak of material nature as being governed by _laws_, it
is sufficiently evident that we use the term in a manner somewhat
metaphorical. The laws to which man’s attention is primarily
directed are _moral_ laws; rules laid down for his actions; rules
for the conscious actions of a person; rules which, as a matter
of possibility, he may obey or may transgress; the latter event
being combined, not with an impossibility, but with a penalty. But
the _Laws of Nature_ are something different from this; they are
rules for that which _things_ are to do and suffer; and this by
no consciousness or will of theirs. They are rules describing the
mode in which things _do_ act; they are invariably obeyed; their
transgression is not punished, it is excluded. The language of a
moral law is, man _shall_ not kill; the language of a Law of Nature
is, a stone _will_ fall to the earth.
These two kinds of laws direct the actions of persons and of
things, by the sort of control of which persons and things are
respectively susceptible; so that the metaphor is very simple; but
it is proper for us to recollect that it is a metaphor, in order
that we may clearly apprehend what is implied in speaking of the
Laws of Nature.
In this phrase are included all properties of the portions of
the material world; all modes of action and rules of causation,
according to which they operate on each other. The whole course of
the visible universe therefore is but the collective result of such
laws; its movements are only the aggregate of _their_ working. All
natural occurrences, in the skies and on the earth, in the organic
and in the inorganic world, are determined by the relations of the
elements and the actions of the forces of which the rules are thus
prescribed.
The relations and rules by which these occurrences are thus
determined necessarily depend on measures of time and space,
motion and force; on quantities which are subject to numerical
measurement, and capable of being connected by mathematical
properties. And thus all things are ordered by number and weight
and measure. “God,” as was said by the ancients, “works by
geometry:” the legislation of the material universe is necessarily
delivered in the language of mathematics; the stars in their
courses are regulated by the properties of conic sections, and
the winds depend on arithmetical and geometrical progressions of
elasticity and pressure.
The constitution of the universe, so far as it can be clearly
apprehended by our intellect, thus assumes a shape involving an
assemblage of mathematical propositions: certain algebraical
formulæ, and the knowledge when and how to apply them, constitute
the last step of the physical science to which we can attain.
The labour and the endowments of ages have been employed in
bringing such science into the condition in which it now exists;
and an exact and extensive discipline in mathematics, followed
by a practical and profound study of the researches of natural
philosophers, can alone put any one in possession of the knowledge
concerning the course of the material world, which is at present
open to man. The general impression, however, which arises from
the view thus obtained of the universe, the results which we
collect from the most careful scrutiny of its administration, may,
we trust, be rendered intelligible without this technical and
laborious study, and to do this is our present object.
It will be our business to show that the laws which really prevail
in nature are, by their _form_, that is, by the nature of the
connexion which they establish among the quantities and properties
which they regulate, remarkably adapted to the office which is
assigned them; and thus offer evidence of selection, design, and
goodness, in the power by which they were established. But these
characters of the legislation of the universe may also be seen, in
many instances, in a manner somewhat different from the selection
of the law. The _nature of the connexion_ remaining the same, the
quantities which it regulates may also in their _magnitude_ bear
marks of selection and purpose. For the law may be the same while
the quantities to which it applies are different. The law of the
gravity which acts to the earth and to Jupiter, is the same; but
the intensity of the force at the surfaces of the two planets is
different. The law which regulates the density of the air at any
point, with reference to the height from the earth’s surface,
would be the same, if the atmosphere were ten times as large, or
only one-tenth as large as it is; if the barometer at the earth’s
surface stood at three inches only, or if it showed a pressure of
thirty feet of mercury.
Now this being understood, the adaptation of a law to its purpose,
or to other laws, may appear in two ways:--either in the form of
the law, or in the amount of the magnitudes which it regulates,
which are sometimes called _arbitrary magnitudes_.
If the attraction of the sun upon the planets did not vary
inversely as the square of the distance, the _form_ of the law
of gravitation would be changed; if this attraction were, at the
earth’s orbit, of a different _value_ from its present one, the
arbitrary magnitude would be changed; and it will appear, in a
subsequent part of this work, that either change would, so far as
we can trace its consequences, be detrimental. The form of the law
determines in what manner the facts shall take place; the arbitrary
magnitude determines how fast, how far, how soon; the one gives a
model, the other a measure of the phenomenon; the one draws the
plan, the other gives the scale on which it is to be executed; the
one gives the rule, the other the rate. If either were wrongly
taken, the result would be wrong too.
CHAPTER III.
_Mutual Adaptation in the Laws of Nature._
To ascertain such laws of nature as we have been describing, is
the peculiar business of science. It is only with regard to a very
small portion of the appearances of the universe, that science, in
any strict application of the term, exists. In very few departments
of research have men been able to trace a multitude of known facts
to causes which appear to be the ultimate material causes, or to
discern the laws which seem to be the most general laws. Yet, in
one or two instances, they have done this, or something approaching
to this; and most especially in the instance of that part of
nature, which it is the object of this treatise more peculiarly to
consider.
The apparent motions of the sun, moon, and stars have been more
completely reduced to their causes and laws than any other class of
phenomena. Astronomy, the science which treats of these, is already
a wonderful example of the degree of such knowledge which man may
attain. The forms of its most important laws may be conceived to
be certainly known; and hundreds of observers in all parts of the
world are daily employed in determining, with additional accuracy,
the arbitrary magnitudes which these laws involve.
The inquiries in which the mutual effects of heat, moisture,
air, and the like elements are treated of, including, among
other subjects, all that we know of the causes of the weather
(meteorology) is a far more imperfect science than astronomy. Yet,
with regard to these agents, a great number of laws of nature have
been discovered, though, undoubtedly, a far greater number remain
still unknown.
So far, therefore, as our knowledge goes, astronomy and meteorology
are parts of natural philosophy in which we may study the order
of nature with such views as we have suggested; in which we may
hope to make out the adaptations and aims which exist in the laws
of nature; and thus to obtain some light on the tendency of this
part of the legislation of the universe, and on the character and
disposition of the Legislator.
The number and variety of the laws which we find established in
the universe is so great, that it would be idle to endeavour
to enumerate them. In their operation they are combined and
intermixed in incalculable and endless perplexity, influencing
and modifying each other’s effects in every direction. If we
attempt to comprehend at once the whole of this complex system,
we find ourselves utterly baffled and overwhelmed by its extent
and multiplicity. Yet, in so far as we consider the bearing of
one part upon another, we receive an impression of adaptation, of
mutual fitness, of conspiring means, of preparation and completion,
of purpose and provision. This impression is suggested by the
contemplation of every part of nature; but the grounds of it, from
the very circumstances of the case, cannot be conveyed in a few
words. It can only be fully educed by leading the reader through
several views and details, and must grow out of the combined
influence of these on a sober and reflecting frame of mind. However
strong and solemn be the conviction which may be derived from a
contemplation of nature, concerning the existence, the power, the
wisdom, the goodness of our Divine Governor, we cannot expect that
this conviction, as resulting from the extremely complex spectacle
of the material world, should be capable of being irresistibly
conveyed by a few steps of reasoning, like the conclusion of
a geometrical proposition, or the result of an arithmetical
calculation.
We shall, therefore, endeavour to point out cases and circumstances
in which the different parts of the universe exhibit this mutual
adaptation, and thus to bring before the mind of the reader the
evidence of wisdom and providence, which the external world
affords. When we have illustrated the correspondencies which
exist in every province of nature, between the qualities of brute
matter and the constitution of living things, between the tendency
to derangement and the conservative influences by which such a
tendency is counteracted, between the office of the minutest speck
and of the most general laws; it will, we trust, be difficult or
impossible to exclude from our conception of this wonderful system,
the idea of a harmonizing, a preserving, a contriving, an intending
Mind; of a Wisdom, Power, and Goodness far exceeding the limits of
our thoughts.
CHAPTER IV.
_Division of the Subject._
In making a survey of the universe, for the purpose of pointing
out such correspondencies and adaptations as we have mentioned, we
shall suppose the general leading facts of the course of nature
to be known, and the explanations of their causes now generally
established among astronomers and natural philosophers to be
conceded. We shall assume therefore that the earth is a solid
globe of ascertained magnitude, which travels round the sun, in
an orbit nearly circular, in a period of about three hundred and
sixty-five days and a quarter, and in the mean time revolves, in an
inclined position, upon its own axis in about twenty-four hours,
thus producing the succession of appearances and effects which
constitute seasons and climates, day and night;--that this globe
has its surface furrowed and ridged with various inequalities,
the waters of the ocean occupying the depressed parts:--that it
is surrounded by an atmosphere, or spherical covering of air;
and that various other physical agents, moisture, electricity,
magnetism, light, operate at the surface of the earth, according to
their peculiar laws. This surface is, as we know, clothed with a
covering of plants, and inhabited by the various tribes of animals,
with all their variety of sensations, wants, and enjoyments. The
relations and connexions of the larger portions of the world, the
sun, the planets, and the stars, the _cosmical_ arrangements of
the system, as they are sometimes called, determine the course
of events among these bodies; and the more remarkable features
of these arrangements are therefore some of the subjects for our
consideration. These cosmical arrangements, in their consequences,
affect also the physical agencies which are at work at the surface
of the earth, and hence come in contact with _terrestrial_
occurrences. They thus influence the functions of plants and
animals. The circumstances in the cosmical system of the universe,
and in the organic system of the earth, which have thus a bearing
on each other, form another of the subjects of which we shall
treat. The former class of considerations attends principally to
the stability and other apparent perfections of the solar system;
the latter to the well-being of the system of organic life by which
the earth is occupied. The two portions of the subject may be
treated as Cosmical Arrangements and Terrestrial Adaptations.
We shall begin with the latter class of adaptations, because in
treating of these the facts are more familiar and tangible, and the
reasonings less abstract and technical, than in the other division
of the subject. Moreover, in this case men have no difficulty
in recognizing as desirable the end which is answered by such
adaptations, and they therefore the more readily consider it _as
an end_. The nourishment, the enjoyment, the diffusion of living
things, are willingly acknowledged to be a suitable object for
contrivance; the simplicity, the permanence, of an inert mechanical
combination might not so readily be allowed to be a manifestly
worthy aim of a Creating Wisdom. The former branch of our argument
may therefore be best suited to introduce to us the Deity as the
institutor of Laws of Nature, though the latter may afterwards give
us a wider view and a clearer insight into one province of his
legislation.
BOOK I.
TERRESTRIAL ADAPTATIONS.
We proceed in this book to point out relations which subsist
between the laws of the inorganic world, that is, the general facts
of astronomy and meteorology; and the laws which prevail in the
organic world, the properties of plants and animals.
With regard to the first kind of laws, they are in the highest
degree various and unlike each other. The intensity and activity
of natural influences follow in different cases the most different
rules. In some instances they are _periodical_, increasing and
diminishing alternately, in a perpetual succession of equal
intervals of time. This is the case with the heat at the earth’s
surface, which has a period of a year; with the light, which has a
period of a day. Other qualities are _constant_, thus the force of
gravity at the same place is always the same. In some cases, a very
simple cause produces very complicated effects; thus the globular
form of the earth, and the inclination of its axis during its
annual motion, give rise to all the variety of climates. In other
cases a very complex and variable system of causes produces effects
comparatively steady and uniform; thus solar and terrestrial heat,
air, moisture, and probably many other apparently conflicting
agents, join to produce our weather, which never deviates very far
from a certain average standard.
Now a general fact, which we shall endeavour to exemplify in the
following chapters, is this:--That those properties of plants and
animals which have reference to agencies of a periodical character,
have also by their nature a periodical mode of working; while
those properties which refer to agencies of constant intensity,
are adjusted to this constant intensity: and again, there are
peculiarities in the nature of organized beings which have
reference to a variety in the conditions of the external world,
as, for instance, the difference of the organized population of
different regions: and there are other peculiarities which have
a reference to the constancy of the average of such conditions,
and the limited range of the deviations from that average; as for
example, that constitution by which each plant and animal is fitted
to exist and prosper in its usual place in the world.
And not only is there this general agreement between the nature of
the laws which govern the organic and inorganic world, but also
there is a coincidence between the _arbitrary magnitudes_ which
such laws involve on the one hand and on the other. Plants and
animals have, in their construction, certain periodical functions,
which have a reference to alternations of heat and cold; the
length of the period which belongs to these functions by their
construction, appears to be that of the period which belongs to the
actual alternations of heat and cold, namely, a year. Plants and
animals have again in their construction certain other periodical
functions, which have a reference to alternations of light and
darkness; the length of the period of such functions appears to
coincide with the natural day. In like manner the other arbitrary
magnitudes which enter into the laws of gravity, of the effects of
air and moisture, and of other causes of permanence, and of change,
by which the influences of the elements operate, are the same
arbitrary magnitudes to which the members of the organic world are
adapted by the various peculiarities of their construction.
The illustration of this view will be pursued in the succeeding
chapters; and when the coincidence here spoken of is distinctly
brought before the reader, it will, we trust, be found to convey
the conviction of a wise and benevolent design, which has been
exercised in producing such an agreement between the internal
constitution and the external circumstances of organized beings.
We shall adduce cases where there is an apparent relation between
the course of operation of the elements and the course of vital
functions; between some fixed measure of time or space, traced
in the lifeless and in the living world; where creatures are
constructed on a certain plan, or a certain scale, and this plan
or this scale is exactly the single one which is suited to their
place on the earth; where it was necessary for the Creator (if we
may use such a mode of speaking) _to take account_ of the weight
of the earth, or the density of the air, or the measure of the
ocean, and where these quantities are rightly taken account of in
the arrangements of creation. In such cases we conceive that we
trace a Creator, who, in producing one part of his work, was not
forgetful or careless of another part; who did not cast his living
creatures into the world to prosper or perish as they might find it
suited to them or not; but fitted together, with the nicest skill,
the world and the constitution which he gave to its inhabitants;
so fashioning it and them, that light and darkness, sun and air,
moist and dry, should become their ministers and benefactors, the
unwearied and unfailing causes of their well-being.
We have spoken of the mutual adaptation of the organic and the
inorganic world. If we were to conceive the contrivance of the
world as taking place in an order of time in the contriving mind,
we might also have to conceive this adaptation as taking place
in one of two ways: we might either suppose the laws of inert
nature to be accommodated to the foreseen wants of living things,
or the organization of life to be accommodated to the previously
established laws of nature. But we are not forced upon any such
mode of conception, or upon any decision between such suppositions:
since, for the purpose of our argument, the consequence of either
view is the same. There is an adaptation somewhere or other,
on either supposition. There is account taken of one part of
the system in framing the other: and the mind which took such
account can be no other than that of the Intelligent Author of the
universe. When indeed we come to see the vast number, the variety,
the extent, the interweaving, the reconciling of such adaptations,
we shall readily allow, that all things are so moulded upon and
locked into each other, connected by such subtilty and profundity
of design, that we may well abandon the idle attempt to trace the
_order_ of thought in the mind of the Supreme Ordainer.
CHAPTER I.
_The Length of the Year._
A year is the most important and obvious of the periods which occur
in the organic, and especially in the vegetable world. In this
interval of time the cycle of most of the external influences which
operate upon plants is completed. There is also in plants a cycle
of internal functions, corresponding to this succession of external
causes. The length of either of these periods might have been
different from what it is, according to any grounds of necessity
which we can perceive. But a certain length is selected in both
instances, and in both instances the same. The length of the year
is so determined as to be adapted to the constitution of most
vegetables; or the construction of vegetables is so adjusted as to
be suited to the length which the year really has, and unsuited
to a duration longer or shorter by any considerable portion. The
vegetable clock-work is so set as to go for a year.
The length of the year or interval of recurrence of the seasons is
determined by the time which the earth employs in performing its
revolution round the sun: and we can very easily conceive the solar
system so adjusted that the year should be longer or shorter than
it actually is. We can imagine the earth to revolve round the sun
at a distance greater or less than that which it at present has,
all the forces of the system remaining unaltered. If the earth were
removed towards the centre by about one-eighth of its distance, the
year would be diminished by about a month; and in the same manner
it would be increased by a month on increasing the distance by
one-eighth. We can suppose the earth at a distance of eighty-four
or a hundred and eight millions of miles, just as easily as at its
present distance of ninety-six millions: we can suppose the earth
with its present stock of animals and vegetables placed where Mars
or where Venus is, and revolving in an orbit like one of theirs: on
the former supposition our year would become twenty-three, on the
latter seven of our present months. Or we can conceive the present
distances of the parts of the system to continue what they are,
and the size, or the density of the central mass, the sun, to be
increased or diminished in any proportion; and in this way the time
of the earth’s revolution might have been increased or diminished
in any degree; a greater velocity, and consequently a diminished
period, being requisite in order to balance an augmented central
attraction. In any of these ways the length of the earth’s natural
year might have been different from what it now is: in the last
way without any necessary alteration, so far as we can see, of
temperature.
Now, if any change of this kind were to take place, the working
of the botanical world would be thrown into utter disorder, the
functions of plants would be entirely deranged, and the whole
vegetable kingdom involved in instant decay and rapid extinction.
That this would be the case, may be collected from innumerable
indications. Most of our fruit trees, for example, require the year
to be of its present length. If the summer and the autumn were
much shorter, the fruit could not ripen; if these seasons were
much longer, the tree would put forth a fresh suit of blossoms, to
be cut down by the winter. Or if the year were twice its present
length, a second crop of fruit would probably not be matured, for
want, among other things, of an intermediate season of rest and
consolidation, such as the winter is. Our forest trees in like
manner appear to need all the seasons of our present year for their
perfection; the spring, summer, and autumn, for the developement of
their leaves and consequent formation of their _proper juice_, and
of wood from this; and the winter for the hardening and solidifying
the substance thus formed.
Most plants, indeed, have some peculiar function adapted to each
period of the year, that is of the now existing year. The sap
ascends with extraordinary copiousness at two seasons, in the
spring and in the autumn, especially the former. The opening of
the leaves and the opening of the flowers of the same plants are
so constant to their times, (their _appointed_ times, as we are
naturally led to call them,) that such occurrences might be taken
as indications of the times of the year. It has been proposed in
this way to select a series of botanical facts which should form a
calendar; and this has been termed a _calendar of Flora_. Thus, if
we consider the time of putting forth leaves,[1] the honeysuckle
protrudes them in the month of January; the gooseberry, currant,
and elder in the end of February, or beginning of March; the
willow, elm, and lime-tree in April; the oak and ash, which are
always the latest among trees, in the beginning or towards the
middle of May. In the same manner the flowering has its regular
time: the mezereon and snowdrop push forth their flowers in
February; the primrose in the month of March; the cowslip in April;
the great mass of plants in May and June; many in July, August,
and September; some, not till the month of October, as the meadow
saffron; and some not till the approach and arrival of winter, as
the laurustinus and arbutus.
The fact which we have here to notice, is the recurrence of these
stages in the developement of plants, at intervals precisely or
very nearly of twelve months. Undoubtedly, this result is in part
occasioned by the action of external stimulants upon the plant,
especially heat, and by the recurrence of the intensity of such
agents. Accordingly, there are slight differences in the times of
such occurrences, according to the backwardness or forwardness of
the season, and according as the climate is genial or otherwise.
Gardeners use artifices which will, to a certain extent, accelerate
or retard the time of developement of a plant. But there are
various circumstances which show that this recurrence of the same
events and equal intervals is not entirely owing to external
causes, and that it depends also upon something in the internal
structure of vegetables. Alpine plants do not wait for the stimulus
of the sun’s heat, but exert such a struggle to blossom, that their
flowers are seen among the yet unmelted snow. And this is still
more remarkable in the naturalization of plants from one hemisphere
to the other. When we transplant our fruit trees to the temperate
regions south of the equator, they continue for some years to
flourish at the period which corresponds to our spring. The reverse
of this obtains, with certain trees of the southern hemisphere.
Plants from the Cape of Good Hope, and from Australia, countries
whose summer is simultaneous with our winter, exhibit their
flowers in the coldest part of the year, as the heaths.
This view of the subject agrees with that maintained by the best
botanical writers. Thus Decandolle observes that after making
allowance for all meteorological causes, which determine the epoch
of flowering, we must reckon as another cause the peculiar nature
of each species. The flowering once determined, appears to be
subject to a law of _periodicity_ and habit.[2]
It appears then that the functions of plants have by their nature a
periodical character; and the length of the period thus belonging
to vegetables is a result of their organization. Warmth and light,
soil and moisture, may in some degree modify, and hasten or retard
the stages of this period; but when the constraint is removed
the natural period is again resumed. Such stimulants as we have
mentioned are not the _causes_ of this periodicity. They do not
produce the varied functions of the plant, and could not occasion
their performance at regular intervals, except the plant possessed
a suitable construction. They could not alter the length of the
cycle of vegetable functions, except within certain very narrow
limits. The processes of the rising of the sap, of the formation of
proper juices, of the unfolding of leaves, the opening of flowers,
the fecundation of the fruit, the ripening of the seed, its proper
deposition in order for the reproduction of a new plant;--all these
operations require a certain portion of time, and could not be
compressed into a space less than a year, or at least could not be
abbreviated in any very great degree. And on the other hand, if the
winter were greatly longer than it now is, many seeds would not
germinate at the return of spring. Seeds which have been kept too
long require stimulants to make them fertile.
If therefore the duration of the seasons were much to change,
the processes of vegetable life would be interrupted, deranged,
distempered. What, for instance, would become of our calendar of
Flora, if the year were lengthened or shortened by six months? Some
of the dates would never arrive in the one case, and the vegetable
processes which mark them would be superseded; some seasons would
be without dates in the other case, and these periods would be
employed in a way harmful to the plants, and no doubt speedily
destructive. We should have not only _a year of confusion_, but, if
it were repeated and continued, a year of death.
But in the existing state of things, the duration of the earth’s
revolution round the sun, and the duration of the revolution of the
vegetable functions of most plants are equal. These two periods are
_adjusted_ to each other. The stimulants which the elements apply
come at such intervals and continue for such times, that the plant
is supported in health and vigour, and enabled to reproduce its
kind. Just such a portion of time is measured out for the vegetable
powers to execute their task, as enables them to do so in the best
manner.
Now such an adjustment must surely be accepted as a proof of
design, exercised in the formation of the world. Why should the
solar year be so long and no longer? or, this being of such a
length, why should the vegetable cycle be exactly of the same
length? Can this be chance? And this occurs, it is to be observed,
not in one, or in a few species of plants, but in thousands. Take a
small portion only of known species, as the most obviously endowed
with this adjustment, and say ten thousand. How should all these
organized bodies be constructed for the same period of a year? How
should all these machines be wound up so as to go for the same
time? Even allowing that they could bear a year of a month longer
or shorter, how do they all come within such limits? No chance
could produce such a result. And if not by chance, how otherwise
could such a coincidence occur, than by an intentional adjustment
of these two things to one another? by a selection of such an
organization in plants, as would fit them to the earth on which
they were to grow; by an adaptation of construction to conditions;
of the scale of the construction to the scale of the conditions.
It cannot be accepted as an explanation of this fact in the
economy of plants, that it is necessary to their existence; that
no plants could possibly have subsisted, and come down to us,
except those which were thus suited to their place on earth.
This is true; but this does not at all remove the necessity of
recurring to design as the origin of the construction by which
the existence and continuance of plants is made possible. A watch
could not go, except there were the most exact adjustment in the
forms and positions of its wheels; yet no one would accept it as
an explanation of the origin of such forms and positions, that
the watch would not go if these were other than they are. If the
objector were to suppose that plants were originally fitted to
years of various lengths, and that such only have survived to the
present time, as had a cycle of a length equal to our present
year, or one which could be accommodated to it; we should reply,
that the assumption is too gratuitous and extravagant to require
much consideration; but that, moreover, it does not remove the
difficulty. How came the functions of plants to be _periodical_ at
all? Here is, in the first instance, an agreement in the form of
the laws that prevail in the organic and in the inorganic world,
which appears to us a clear evidence of design in their Author.
And the same kind of reply might be made to any similar objection
to our argument. Any supposition that the universe has gradually
approximated to that state of harmony among the operations of its
different parts, of which we have one instance in the coincidence
now under consideration, would make it necessary for the objector
to assume a previous state of things preparatory to this perfect
correspondence. And in this preparatory condition we should still
be able to trace the rudiments of that harmony, for which it was
proposed to account: so that even the most unbounded license of
hypothesis would not enable the opponent to obliterate the traces
of an intentional adaptation of one part of nature to another.
Nor would it at all affect the argument, if these periodical
occurrences could be traced to some proximate cause: if for
instance it could be shown, that the budding or flowering of
plants is brought about at particular intervals, by the nutriment
accumulated in their vessels during the preceding months. For the
question would still remain, how their functions were so adjusted,
that the accumulation of the nutriment necessary for budding and
flowering, together with the operation itself, comes to occupy
exactly a year, instead of a month only, or ten years. There must
be in their structure some reference to time: how did such a
reference occur? how was it i determined to the particular time of
the earth’s revolution round the sun? This could be no otherwise,
as we conceive, than by design and appointment.
We are left therefore with this manifest adjustment before us, of
two parts of the universe, at first sight so remote; the dimensions
of the solar system and the powers of vegetable life. These two
things are so related, that one has been made to fit the other. The
relation is as clear as that of a watch to a sundial. If a person
were to compare the watch with the dial, hour after hour, and day
after day, it would be impossible for him not to believe that the
watch had been _contrived_ to accommodate itself to the solar day.
We have at least ten thousand kinds of vegetable watches of the
most various forms, which are all accommodated to the solar year;
and the evidence of contrivance seems to be no more capable of
being eluded in this case than in the other.
The same kind of argument might be applied to the animal creation.
The pairing, nesting, hatching, fledging, and flight of birds,
for instance, occupy each its peculiar time of the year; and,
together with a proper period of rest, fill up the twelve months.
The transformations of most insects have a similar reference to the
seasons, their progress and duration. “In every species,” (except
man,) says a writer[3] on animals, “there is a peculiar period of
the year in which the reproductive system exercises its energies.
And the season of love and the period of gestation are so arranged
that the young ones are produced at the time wherein the conditions
of temperature are most suited to the commencement of life.” It is
not our business here to consider the details of such provisions,
beautiful and striking as they are. But the prevalence of the great
law of periodicity in the vital functions of organized beings
will be allowed to have a claim to be considered in its reference
to astronomy, when it is seen that their periodical constitution
derives its use from the periodical nature of the motions of the
planets round the sun; and that the duration of such cycles in the
existence of plants and animals has a reference to the arbitrary
elements of the solar system: a reference which, we maintain, is
inexplicable and unintelligible, except by admitting into our
conceptions; an Intelligent Author, alike of the organic and
inorganic universe.