in the first instance, disguised in a transparent liquid; the solid
matter of which our woods and forests are composed is also, for the
most part disguised in a transparent gas, which is mixed in small
quantities with the air of our atmosphere. This gas is formed by the
union of carbon and oxygen, and is called carbonic acid gas. The
carbonic acid of the air being subjected to an action somewhat
analogous to that of the electric current in the case of our lead and
silver solutions, has its carbon liberated and deposited as woody
fibre. The watery vapour of the air is subjected to similar action;
its hydrogen is liberated from its oxygen, and lies down side by side
with the carbon in the tissues of the tree. The oxygen in both cases
is permitted to wander away into the atmosphere. But what is it in
nature that plays the part of the electric current in our experiments,
tearing asunder the locked atoms of carbon, oxygen, and hydrogen? The
rays of the sun. The leaves of plants which absorb both the carbonic
acid and the aqueous vapour of the air, answer to the cells in which
our decompositions took place. And just as the molecular attractions
of the silver and the lead found expression in those beautiful
branching forms seen in our experiments, so do the molecular
attractions of the liberated carbon and hydrogen find expression in
the architecture of grasses, plants, and trees.
In the fall of a cataract and the rush of the wind we have examples of
mechanical power. In the combinations of chemistry and in the
formation of crystals and vegetables we have examples of molecular
power. You have learned how the atoms of oxygen and hydrogen rush
together to form water. I have not thought it necessary to dwell upon
the mighty mechanical energy of their act of combination; but it may
be said, in passing, that the clashing together of 1 lb. of hydrogen
and 8 lbs. of oxygen to form 9 lbs. of aqueous vapour, is greater than
the shock of a weight of 1,000 tons falling from a height of 20 feet
against the earth. Now, in order that the atoms of oxygen and
hydrogen should rise by their mutual attractions to the velocity
corresponding to this enormous mechanical effect, a certain distance
must exist between the particles. It is in rushing over this that the
velocity is attained.
*****
This idea of distance between the attracting atoms is of the highest
importance in our conception of the system of the world. For the
matter of the world may be classified under two distinct heads: atoms
and molecules which have already combined and thus satisfied their
mutual attractions, and atoms and molecules which have not yet
combined, and whose mutual attractions are, therefore, unsatisfied.
Now, as regards motive power, we are entirely dependent on atoms and
molecules of the latter kind. Their attractions can produce motion,
because sufficient distance intervenes between the attracting atoms,
and it is this atomic motion that we utilise in our machines. Thus we
can get power out of oxygen and hydrogen by the act of their union;
but once they are combined, and once the vibratory motion consequent
on their combination has been expended, no further power can be got
out of their mutual attraction. As dynamic agents they are dead. The
materials of the earth's crust consist for the most part of substances
whose atoms have already closed in chemical union--whose mutual
attractions are satisfied. Granite, for instance, is a widely
diffused substance; but granite consists, in great part, of silicon,
oxygen, potassium, calcium, and aluminum, whose atoms united long ago,
and are therefore dead. Limestone is composed of carbon, oxygen, and
a metal called calcium, the atoms of which have already closed in
chemical union, and are therefore finally at rest. In this way we
might go over nearly the whole of the materials of the earth's crust,
and satisfy ourselves that though they were sources of power in ages
past, and long before any creature appeared on the earth capable of
turning their power to account, they are sources of power no longer.
And here we might halt for a moment to remark on that tendency, so
prevalent in the world, to regard everything as made for human use.
Those who entertain this notion, hold, I think, an overweening opinion
of their own importance in the system of nature. Flowers bloomed
before men saw them, and the quantity of power wasted before man could
utilise it is all but infinite compared with what now remains. We are
truly heirs of all the ages; but as honest men it behoves us to learn
the extent of our inheritance, and as brave ones not to whimper if it
should prove less than we had supposed. The healthy attitude of mind
with reference to this subject is that of the poet, who, when asked
whence came the rhodora, joyfully acknowledged his brotherhood with
the flower:
Why thou wert there, O rival of the rose!
I never thought to ask, I never knew,
But in my simple ignorance supposed
The self-same power that brought me there brought you.
Emerson.
A few exceptions to the general state of union of the molecules of the
earth's crust--vast in relation to us, but trivial in comparison to
the total store of which they are the residue--still remain. They
constitute our main sources of motive power. By far the most
important of these are our beds of coal. Distance still intervenes
between the atoms of carbon and those of atmospheric oxygen, across
which the atoms may be urged by their mutual attractions; and we can
utilise the motion thus produced. Once the carbon and the oxygen have
rushed together, so as to form carbonic acid, their mutual attractions
are satisfied; and, while they continue in this condition, as dynamic
agents they are dead. Our woods and forests are also sources of
mechanical energy, because they have the power of uniting with the
atmospheric oxygen. Passing from plants to animals, we find that the
source of motive power just referred to is also the source of muscular
power. A horse can perform work, and so can a man; but this work is
at bottom the molecular work of the transmuted food and the oxygen of
the air. We inhale this vital gas, and bring it into sufficiently
close proximity with the carbon and the hydrogen of the body. These
unite in obedience to their mutual, attractions; and their motion
towards each other, properly turned to account by the wonderful
mechanism of the body, becomes muscular motion.
One fundamental thought pervades all these statements: there is one
tap root from which they all spring. This is the ancient maxim that
out of nothing nothing comes; that neither in the organic world nor in
the inorganic is power produced without the expenditure of power; that
neither in the plant nor in the animal is there a creation of force or
motion. Trees grow, and so do men and horses; and here we have new
power incessantly introduced upon the earth. But its source, as I
have already stated, is the sun. It is the sun that separates the
carbon from the oxygen of the carbonic acid, and thus enables them to
recombine. Whether they recombine in the furnace of the steam-engine
or in the animal body, the origin of the power they produce is the
same. In this sense we are all 'souls of fire and children of the
sun.' But, as remarked by Helmholtz, we must be content to share our
celestial pedigree with the meanest of living things.
Some estimable persons, here present, very possibly shrink from
accepting these statements; they may be frightened by their apparent
tendency towards what is called materialism--a word which, to many
minds, expresses something very dreadful. But it ought to be known
and avowed that the physical philosopher, as such, must be a pure
materialist. His enquiries deal with matter and force, and with them
alone. And whatever be the forms which matter and force assume,
whether in the organic world or the inorganic, whether in the
coal-beds and forests of the earth, or in the brains and muscles of
men, the physical philosopher will make good his right to investigate
them. It is perfectly vain to attempt to stop enquiry in this
direction. Depend upon it, if a chemist by bringing the proper
materials together, in a retort or crucible, could make a baby, he
would do it. There is no law, moral or physical, forbidding him to do
it. At the present moment there are, no doubt, persons experimenting
on the possibility of producing what we call life out of inorganic
materials. Let them pursue their studies in peace; it is only by such
trials that they will learn the limits of their own powers and the
operation of the laws of matter and force.
But while thus making the largest demand for freedom of
investigation--while I consider science to be alike powerful as an
instrument of intellectual culture and as a ministrant to the material
wants of men; if you ask me whether it has solved, or is likely in our
day to solve, the problem of this universe, I must shake my head in
doubt. You remember the first Napoleon's question, when the savants
who accompanied him to Egypt discussed in his presence the origin of
the universe, and solved it to their own apparent satisfaction. He
looked aloft to the starry heavens, and said, 'It is all very well,
gentlemen; but who made these?' That question still remains
unanswered, and science makes no attempt to answer it. As far as I
can see, there is no quality in the human intellect which is fit to be
applied to the solution of the problem. It entirely transcends us.
The mind of man may be compared to a musical instrument with a certain
range of notes, beyond which in both directions we have an infinitude
of silence. The phenomena of matter and force lie within our
intellectual range, and as far as they reach we will at all hazards
push our enquiries. But behind, and above, and around all, the real
mystery of this universe lies unsolved, and, as far as we are
concerned, is incapable of solution. Fashion this mystery as you
will, with that I have nothing to do. But let your conception of it
not be an unworthy one. Invest that conception with your highest and
holiest thought, but be careful of pretending to know more about it
than is given to man to know. Be careful, above all things, of
professing to see in the phenomena of the material world the evidences
of Divine pleasure or displeasure. Doubt those who would deduce from
the fall of the tower of Siloam the anger of the Lord against those
who were crushed. Doubt equally those who pretend to see in cholera,
cattle-plague, and bad harvests, evidences of Divine anger. Doubt
those spiritual guides who in Scotland have lately propounded the
monstrous theory that the depreciation of railway scrip is a
consequence of railway travelling on Sundays. Let them not, as far as
you are concerned, libel the system of nature with their ignorant
hypotheses. Looking from the solitudes of thought into this highest
of questions, and seeing the puerile attempts often made to solve it,
well might the mightiest of living Scotchmen--that strong and earnest
soul, who has made every soul of like nature in these islands his
debtor--well, I say, might your noble old Carlyle scornfully retort on
such interpreters of the ways of God to men:
The Builder of this universe was wise,
He formed all souls, all systems, planets, particles;
The plan he formed his worlds and Aeons by,
Was--Heavens!--was thy small nine-and-thirty articles!
********************
Here, indeed, we arrive at the barrier which needs to be perpetually
pointed out; alike to those who seek materialistic explanations of
mental phenomena, and to those who are alarmed lest such explanations
may be found. The last class prove by their fear almost as much as
the first prove by their hope, that they believe Mind may possibly be
interpreted in terms of Matter; whereas many whom they vituperate as
materialists are profoundly convinced that there is not the remotest
possibility of so interpreting them.
HERBERT SPENCER.
====================
VI. SCIENTIFIC MATERIALISM.
[Footnote: President's Address to the Mathematical and Physical
Section of the British Association at Norwich.]
1868.
THE celebrated Fichte, in his lectures on the 'Vocation of the
Scholar,' insisted on a culture which should be not one-sided, but
all-sided. The scholar's intellect was to expand spherically, and not
in a single direction only. In one direction, however, Fichte
required that the scholar should apply himself directly to nature,
become a creator of knowledge, and thus repay, by original labours of
his own, the immense debt he owed to the labours of others. It was
these which enabled him to supplement the knowledge derived from his
own researches, so as to render his culture rounded and not one-sided.
As regards science, Fichte's idea is to some extent illustrated by the
constitution and labours of the British Association. We have here a
body of men engaged in the pursuit of Natural Knowledge, but variously
engaged. While sympathising with each of its departments, and
supplementing his culture by knowledge drawn from all of them, each
student amongst us selects one subject for the exercise of his own
original faculty--one line, along which he may carry the light of his
private intelligence a little way into the darkness by which all
knowledge is surrounded. Thus, the geologist deals with the rocks;
the biologist with the conditions and phenomena of life; the
astronomer with stellar masses and motions; the mathematician with the
relations of space and number; the chemist pursues his atoms; while
the physical investigator has his own large field in optical, thermal,
electrical, acoustical, and other phenomena. The British Association
then, as a whole, faces physical nature on all sides, and pushes
knowledge centrifugally outwards, the sum of its labours constituting
what Fichte might call the sphere of natural knowledge. In the
meetings of the Association it is found necessary to resolve this
sphere into its component parts, which take concrete form under the
respective letters of our Sections.
Mathematics and Physics have been long accustomed to coalesce, and
here they form a single section. No matter how subtle a natural
phenomenon may be, whether we observe it in the region of sense, or
follow it into that of imagination, it is in the long run reducible to
mechanical laws. But the mechanical data once guessed or given,
mathematics are all-powerful as an instrument of deduction. The
command of Geometry over the relations of space, and the far-reaching
power which Analysis confers, are potent both As means of physical
discovery, and of reaping the entire fruits of discovery. Indeed,
without mathematics, expressed or implied, our knowledge of physical
science would be both friable and incomplete.
Side by side with the mathematical method we have the method of
experiment. Here from a starting-point furnished by his own
researches or those of others, the investigator proceeds by combining
intuition and verication. He ponders the knowledge he possesses, and
tries to push it further; he guesses, and checks his guess; he
conjectures, and confirms or explodes his conjecture. These guesses
and conjectures are by no means leaps in the dark; for knowledge once
gained casts a faint light beyond its own immediate boundaries. There
is no discovery so limited as not to illuminate something beyond
itself. The force of intellectual penetration into this penumbral
region which surrounds actual knowledge is not, as some seem to think,
dependent upon method, but upon the genius of the investigator. There
is, however, no genius so gifted as not to need control and
verification. The profoundest minds know best that Nature's ways are
not at all times their ways, and that the brightest flashes in the
world of thought are incomplete until they have been proved to have
their counterparts in the world of fact. Thus the vocation of the
true experimentalist may be defined as the continued exercise of
spiritual insight, and its incessant correction and realisation. His
experiments constitute a body, of which his purified intuitions are,
as it were, the soul.
Partly through mathematical and partly through experimental research,
physical science has, of late years, assumed a momentous position in
the world. Both in a material and in an intellectual point of view it
has produced, and it is destined to produce, immense changes--vast
social ameliorations, and vast alterations in the popular conception
of the origin, rule, and governance of natural things. By science, in
the physical world, miracles are wrought, while philosophy is
forsaking its ancient metaphysical channels, and pursuing others which
have been opened, or indicated by, scientific research. This must
become more and more the case as philosophical writers become more
deeply imbued with the methods of science, better acquainted with the
facts which scientific men have established, and with the great
theories which they have elaborated.
If you look at the face of a watch, you see the hour and minute-hands,
and possibly also a second-hand, moving over the graduated dial. Why
do these hands move? and why are their relative motions such as they
are observed to be? These questions cannot be answered without
opening the watch, mastering its various parts, and ascertaining their
relationship to each other. When this is done, we find that the
observed motion of the hands follows of necessity from the inner
mechanism of the watch when acted upon by the force invested in the
spring. The motion of the hands may be called a phenomenon of art,
but the case is similar with the phenomena of nature. These also have
their inner mechanism and their store of force to set that mechanism
going. The ultimate problem of physical science is to reveal this
mechanism, to discern this store, and to show that from the combined
action of both, the phenomena of which they constitute the basis,
must, of necessity, flow.
I thought an attempt to give you even a brief and sketchy illustration
of the manner in which scientific thinkers regard this problem, would
not be uninteresting to you on the present occasion; more especially
as it will give me occasion to say a word or two on the tendencies and
limits of modern science; to point out the region which men of science
claim as their own, and where it is futile to oppose their advance;
and also to define, if possible, the bourne between this and that
other region, to which the questionings and yearnings of the
scientific intellect are directed in vain.
But here your tolerance will be needed. It was the American Emerson,
I think, who said that it is hardly possible to state any truth
strongly, without apparent injustice to some other truth. Truth is
often of a dual character, taking the form of a magnet with two poles;
and many of the differences which agitate the thinking part of mankind
are to be traced to the exclusiveness with which partisan reasoners
dwell upon one half of the duality, in forgetfulness of the other. The
proper course appears to be to state both halves strongly, and allow
each its fair share in the formation of the resultant conviction. But
this waiting for the statement of the two sides of a question implies
patience. It implies a resolution to suppress indignation, if the
statement of the one half should clash with our convictions; and to
repress equally undue elation, if the half-statement should happen to
chime in with our views. It implies a determination to wait calmly
for the statement of the whole, before we pronounce judgment in the
form of either acquiescence or dissent.
This premised, and I trust accepted, let us enter upon our task. There
have been writers who affirmed that the Pyramids of Egypt were natural
productions; and in his early youth Alexander von Humboldt wrote a
learned essay with the express object of refuting this notion. We now
regard the pyramids as the work of men's hands, aided probably by
machinery of which no record remains. We picture to ourselves the
swarming workers toiling at those vast erections, lifting the inert
stones, and, guided by the volition, the skill, and possibly at times
by the whip of the architect, placing them in their proper positions.
The blocks, in this case, were moved and posited by a power external
to themselves, and the final form of the pyramid expressed the thought
of its human builder.
Let us pass from this illustration of constructive power to another of
a different kind. When a solution of common salt is slowly
evaporated, the water which holds the salt in solution disappears, but
the salt itself remains behind. At a certain stage of concentration
the salt can no longer retain the liquid form; its particles, or
molecules, as they are called, begin to deposit themselves as minute
solids--so minute, indeed, as to defy all microscopic power. As
evaporation continues, solidification goes on, and we finally obtain,
through the clustering together of innumerable molecules, a finite
crystalline mass of a definite form. What is this form? It sometimes
seems a mimicry of the architecture of Egypt. We have little pyramids
built by the salt, terrace above terrace from base to apex, forming a
series of steps resembling those up which the traveller in Egypt is
dragged by his guides. The human mind is as little disposed to look
without questioning at these pyramidal salt-crystals, as to look at
the pyramids of Egypt, without enquiring whence they came. How, then,
are those salt-pyramids built up?
Guided by analogy, you may, if you like, suppose that, swarming among
the constituent molecules of the salt, there is an invisible
population, controlled and coerced by some invisible master, placing
the atomic blocks in their positions. This, however, is not the
scientific idea, nor do I think your good sense will accept it as a
likely one. The scientific idea is, that the molecules act upon each
other without the intervention of slave labour; that they attract each
other, and repel each other, at certain definite points, or poles, and
in certain definite directions; and that the pyramidal form is the
result of this play of attraction and repulsion. While, then, the
blocks of Egypt were laid down by a power external to themselves,
these molecular blocks of salt are self-posited, being fixed in their
places by the inherent forces with which they act upon each other.
I take common salt as an illustration, because it is so familiar to us
all; but any other crystalline substance would answer my purpose
equally well. Everywhere, in fact, throughout inorganic nature, we
have this formative power, as Fichte would call it--this structural
energy ready to come into play, and build the ultimate particles of
matter into definite shapes. The ice of our winters, and of our polar
regions, is its handiwork, and so also are the quartz, felspar, and
mica of our rocks. Our chalk-beds are for the most part composed of
minute shells, which are also the product of structural energy; but
behind the shell, as a whole, lies a more remote and subtle formative
act. These shells are built up of little crystals of talc-spar, and,
to form these crystals, the structural force had to deal with the
intangible molecules of carbonate of lime. This tendency on the part
of matter to organise itself, to grow into shape, to assume definite
forms in obedience to the definite action of force, is, as I have
said, all-pervading. It is in the ground on which you tread, in the
water you drink, in the air you breathe. Incipient life, as it were,
manifests itself throughout the whole of what we call inorganic
nature.
The forms of the minerals resulting from this play of polar forces are
various, and exhibit different degrees of complexity. Men of science
avail themselves of all possible means of exploring their molecular
architecture. For this purpose they employ in turn, as agents of
exploration, light, heat, magnetism, electricity, and sound. Polarised
light is especially useful and powerful here. A beam of such light,
when sent in among the molecules of a crystal, is acted on by them,
and from this action we infer with more or less clearness the manner
in which the molecules are arranged. That differences, for example,
exist between the inner structure of rocksalt and that of crystallised
sugar or sugar-candy, is thus strikingly revealed. These actions
often display themselves in chromatic phenomena of great splendour,
the play of molecular force being so regulated as to cause the removal
of some of the coloured constituents of white light, while others are
left with increased intensity behind.