contradiction in terms. Did M. Flourens ever visit one of the prettiest
watering-places of "la belle France," the Baie d'Arcachon? If so, he
will probably have passed through the district of the Landes, and will
have had an opportunity of observing the formation of "dunes" on a grand
scale. What are these "dunes?" The winds and waves of the Bay of Biscay
have not much consciousness, and yet they have with great care
"selected," from among an infinity of masses of silex of all shapes and
sizes, which have been submitted to their action, all the grains of sand
below a certain size, and have heaped them by themselves over a great
area. This sand has been "unconsciously selected" from amidst the gravel
in which it first lay with as much precision as if man had "consciously
selected" it by the aid of a sieve. Physical Geology is full of such
selections--of the picking out of the soft from the hard, of the soluble
from the insoluble, of the fusible from the infusible, by natural
agencies to which we are certainly not in the habit of ascribing
consciousness.
But that which wind and sea are to a sandy beach, the sum of influences,
which we term the "conditions of existence," is to living organisms. The
weak are sifted out from the strong. A frosty night "selects" the hardy
plants in a plantation from among the tender ones as effectually as if
it were the wind, and they, the sand and pebbles, of our illustration;
or, on the other hand, as if the intelligence of a gardener had been
operative in cutting the weaker organisms down. The thistle, which has
spread over the Pampas, to the destruction of native plants, has been
more effectually "selected" by the unconscious operation of natural
conditions than if a thousand agriculturists had spent their time in
sowing it.
It is one of Mr. Darwin's many great services to Biological science that
he has demonstrated the significance of these facts. He has shown
that--given variation and given change of conditions--the inevitable
result is the exercise of such an influence upon organisms that one is
helped and another is impeded; one tends to predominate, another to
disappear; and thus the living world bears within itself, and is
surrounded by, impulses towards incessant change.
But the truths just stated are as certain as any other physical laws,
quite independently of the truth, or falsehood, of the hypothesis which
Mr. Darwin has based upon them; and that M. Flourens, missing the
substance and grasping at a shadow, should be blind to the admirable
exposition of them, which Mr. Darwin has given, and see nothing there
but a "dernière erreur du dernier siècle"--a personification of
Nature--leads us indeed to cry with him: "O lucidité! O solidité de
l'esprit Français, que devenez-vous?"
M. Flourens has, in fact, utterly failed to comprehend the first
principles of the doctrine which he assails so rudely. His objections to
details are of the old sort, so battered and hackneyed on this side of
the Channel, that not even a Quarterly Reviewer could be induced to pick
them up for the purpose of pelting Mr. Darwin over again. We have Cuvier
and the mummies; M. Roulin and the domesticated animals of America; the
difficulties presented by hybridism and by Palæontology; Darwinism a
_rifacciamento_ of De Maillet and Lamarck; Darwinism a system without a
commencement, and its author bound to believe in M. Pouchet, &c. &c. How
one knows it all by heart, and with what relief one reads at p. 65--
"Je laisse M. Darwin!"
But we cannot leave M. Flourens without calling our readers' attention
to his wonderful tenth chapter, "De la Préexistence des Germes et de
l'Epigénèse," which opens thus:--
"Spontaneous generation is only a chimæra. This point established,
two hypotheses remain: that of _pre-existence_ and that of
_epigenesis_. The one of these hypotheses has as little foundation
as the other." (P. 163.)
"The doctrine of _epigenesis_ is derived from Harvey: following by
ocular inspection the development of the new being in the Windsor
does, he saw each part appear successively, and taking the moment
of _appearance_ for the moment of _formation_ he imagined
_epigenesis_." (P. 165.)
On the contrary, says M. Flourens (p. 167),
"The new being is formed at a stroke (_tout d'un coup_), as a
whole, instantaneously; it is not formed part by part, and at
different times. It is formed at once; it is formed at the single
_individual_ moment at which the conjunction of the male and female
elements takes place."
It will be observed that M. Flourens uses language which cannot be
mistaken. For him, the labours of Von Baer, of Rathke, of Coste, and
their contemporaries and successors in Germany, France, and England, are
non-existent; and, as Darwin "_imagina_" natural selection, so Harvey
"_imagina_" that doctrine which gives him an even greater claim to the
veneration of posterity than his better known discovery of the
circulation of the blood.
Language such as that we have quoted is, in fact, so preposterous, so
utterly incompatible with anything but absolute ignorance of some of the
best established facts, that we should have passed it over in silence
had it not appeared to afford some clue to M. Flourens' unhesitating, _à
priori_, repudiation of all forms of the doctrine of the progressive
modification of living beings. He whose mind remains uninfluenced by an
acquaintance with the phænomena of development, must indeed lack one of
the chief motives towards the endeavour to trace a genetic relation
between the different existing forms of life. Those who are ignorant of
Geology, find no difficulty in believing that the world was made as it
is; and the shepherd, untutored in history, sees no reason to regard the
green mounds which indicate the site of a Roman camp, as aught but part
and parcel of the primæval hill-side. So M. Flourens, who believes that
embryos are formed "tout d'un coup," naturally finds no difficulty in
conceiving that species came into existence in the same way.
FOOTNOTES:
[65] "Die Radiolarien: eine Monographie," p. 231.
[66] Space will not allow us to give Professor Kölliker's arguments in
detail; our readers will find a full and accurate version of them in the
_Reader_ for August 13th and 20th, 1864.
[67] If, on the contrary, we follow the analogy of the more complex
forms of Agamogenesis, such as that exhibited by some _Trematoda_ and by
the _Aphides_, the Hyæna must produce, asexually, a brood of asexual
Dogs, from which other sexless Dogs must proceed. At the end of a
certain number of terms of the series, the Dogs would acquire sexes and
generate young; but these young would be, not Dogs, but Hyænas. In fact,
we have _demonstrated_, in Agamogenetic phænomena, that inevitable
recurrence to the original type, which is _asserted_ to be true of
variations in general, by Mr. Darwin's opponents; and which, if the
assertion could be changed into a demonstration, would, in fact, be
fatal to his hypothesis.
XIV.
ON DESCARTES' "DISCOURSE TOUCHING THE METHOD OF USING ONE'S REASON
RIGHTLY AND OF SEEKING SCIENTIFIC TRUTH."
It has been well said that "all the thoughts of men, from the beginning
of the world until now, are linked together into one great chain;" but
the conception of the intellectual filiation of mankind which is
expressed in these words may, perhaps, be more fitly shadowed forth by a
different metaphor. The thoughts of men seem rather to be comparable to
the leaves, flowers, and fruit upon the innumerable branches of a few
great stems, fed by commingled and hidden roots. These stems bear the
names of the half-a-dozen men, endowed with intellects of heroic force
and clearness, to whom we are led, at whatever point of the world of
thought the attempt to trace its history commences; just as certainly as
the following up the small twigs of a tree to the branchlets which bear
them, and tracing the branchlets to their supporting branches, brings
us, sooner or later, to the bole.
It seems to me that the thinker who, more than any other, stands in the
relation of such a stem towards the philosophy and the science of the
modern world is René Descartes. I mean, that if you lay hold of any
characteristic product of modern ways of thinking, either in the region
of philosophy, or in that of science, you find the spirit of that
thought, if not its form, to have been present in the mind of the great
Frenchman.
There are some men who are counted great because they represent the
actuality of their own age, and mirror it as it is. Such an one was
Voltaire, of whom it was epigrammatically said, "he expressed
everybody's thoughts better than anybody."[68] But there are other men
who attain greatness because they embody the potentiality of their own
day, and magically reflect the future. They express the thoughts which
will be everybody's two or three centuries after them. Such an one was
Descartes.
Born, in 1596, nearly three hundred years ago, of a noble family in
Touraine, René Descartes grew up into a sickly and diminutive child,
whose keen wit soon gained him that title of "the Philosopher," which,
in the mouths of his noble kinsmen, was more than, half a reproach. The
best schoolmasters of the day, the Jesuits, educated him as well as a
French boy of the seventeenth century could be educated. And they must
have done their work honestly and well, for, before his schoolboy days
were over, he had discovered that the most of what he had learned,
except in mathematics, was devoid of solid and real value.
"Therefore," says he, in that "Discourse"[69] which I have taken
for my text, "as soon as I was old enough to be set free from the
government of my teachers, I entirely forsook the study of letters;
and determining to seek no other knowledge than that which I could
discover within myself, or in the great book of the world, I spent
the remainder of my youth in travelling; in seeing courts and
armies; in the society of people of different humours and
conditions; in gathering varied experience; in testing myself by
the chances of fortune; and in always trying to profit by my
reflections on what happened.... And I always had an intense desire
to learn how to distinguish truth from falsehood, in order to be
clear about my actions, and to walk surefootedly in this life."
But "learn what is true, in order to do what is right," is the summing
up of the whole duty of man, for all who are unable to satisfy their
mental hunger with the east wind of authority; and to those of us
moderns who are in this position, it is one of Descartes' great claims
to our reverence as a spiritual ancestor, that, at three-and-twenty, he
saw clearly that this was his duty, and acted up to his conviction. At
two-and-thirty, in fact, finding all other occupations incompatible with
the search after the knowledge which leads to action, and being
possessed of a modest competence, he withdrew into Holland; where he
spent nine years in learning and thinking, in such retirement that only
one or two trusted friends knew of his whereabouts.
In 1637 the firstfruits of these long meditations were given to the
world in the famous "Discourse touching the Method of using Reason
rightly and of seeking scientific Truth," which, at once an
autobiography and a philosophy, clothes the deepest thought in language
of exquisite harmony, simplicity, and clearness.
The central propositions of the whole "Discourse" are these. There is a
path that leads to truth so surely, that if any one who will follow it
must needs reach the goal, whether his capacity be great or small. And
there is one guiding rule by which a man may always find this path, and
keep himself from straying when he has found it. This golden rule
is--give unqualified assent to no propositions but those the truth of
which is so clear and distinct that they cannot be doubted.
The enunciation of this great first commandment of science consecrated
Doubt. It removed Doubt from the seat of penance among the grievous sins
to which it had long been condemned, and enthroned it in that high place
among the primary duties, which is assigned to it by the scientific
conscience of these latter days. Descartes was the first among the
moderns to obey this commandment deliberately; and, as a matter of
religious duty, to strip off all his beliefs and reduce himself to a
state of intellectual nakedness, until such time as he could satisfy
himself which were fit to be worn. He thought a bare skin healthier than
the most respectable and well-cut clothing of what might, possibly, be
mere shoddy.
When I say that Descartes consecrated doubt, you must remember that it
was that sort of doubt which Goethe has called "the active scepticism,
whose whole aim is to conquer itself;"[70] and not that other sort which
is born of flippancy and ignorance, and whose aim is only to perpetuate
itself, as an excuse for idleness and indifference. But it is impossible
to define what is meant by scientific doubt better than in Descartes'
own words. After describing the gradual progress of his negative
criticism, he tells us:--
"For all that, I did not imitate the sceptics, who doubt only for
doubting's sake, and pretend to be always undecided; on the
contrary, my whole intention was to arrive at certainty, and to dig
away the drift and the sand until I reached the rock or the clay
beneath."
And further, since no man of common sense, when he pulls down his house
for the purpose of rebuilding it, fails to provide himself with some
shelter while the work is in progress; so, before demolishing the
spacious, if not commodious, mansion of his old beliefs, Descartes
thought it wise to equip himself with what he calls "_une morale par
provision_," by which he resolved to govern his practical life until
such time as he should be better instructed. The laws of this
"provisional self-government" are embodied in four maxims, of which one
binds our philosopher to submit himself to the laws and religion in
which he was brought up; another, to act, on all those occasions which
call for action, promptly and according to the best of his judgment, and
to abide, without repining, by the result: a third rule is to seek
happiness in limiting his desires, rather than in attempting to satisfy
them; while the last is to make the search after truth the business of
his life.
Thus prepared to go on living while he doubted, Descartes proceeded to
face his doubts like a man. One thing was clear to him, he would not lie
to himself--would, under no penalties, say, "I am sure" of that of which
he was not sure; but would go on digging and delving until he came to
the solid adamant; or, at worst, made sure there was no adamant. As the
record of his progress tells us, he was obliged to confess that life is
full of delusions; that authority may err; that testimony may be false
or mistaken; that reason lands us in endless fallacies; that memory is
often as little trustworthy as hope; that the evidence of the very
senses may be misunderstood; that dreams are real as long as they last,
and that what we call reality may be a long and restless dream. Nay, it
is conceivable that some powerful and malicious being may find his
pleasure in deluding us, and in making us believe the thing which is
not, every moment of our lives. What, then, is certain? What even, if
such a being exists, is beyond the reach of his powers of delusion? Why,
the fact that the thought, the present consciousness, exists. Our
thoughts may be delusive, but they cannot be fictitious. As thoughts,
they are real and existent, and the cleverest deceiver cannot make them
otherwise.
Thus, thought is existence. More than that, so far as we are concerned,
existence is thought, all our conceptions of existence being some kind
or other of thought. Do not for a moment suppose that these are mere
paradoxes or subtleties. A little reflection upon the commonest facts
proves them to be irrefragable truths. For example, I take up a marble,
and I find it to be a red, round, hard, single body. We call the
redness, the roundness, the hardness, and the singleness, "qualities" of
the marble; and it sounds, at first, the height of absurdity to say that
all these qualities are modes of our own consciousness, which cannot
even be conceived to exist in the marble. But consider the redness, to
begin with. How does the sensation of redness arise? The waves of a
certain very attenuated matter, the particles of which are vibrating
with vast rapidity, but with very different velocities, strike upon the
marble, and those which vibrate with one particular velocity are thrown
off from its surface in all directions. The optical apparatus of the eye
gathers some of these together, and gives them such a course that they
impinge upon the surface of the retina, which is a singularly delicate
apparatus, connected with the termination of the fibres of the optic
nerve. The impulses of the attenuated matter, or ether, affect this
apparatus and the fibres of the optic nerve in a certain way; and the
change in the fibres of the optic nerve produces yet other changes in
the brain; and these, in some fashion unknown to us, give rise to the
feeling, or consciousness, of redness. If the marble could remain
unchanged, and either the rate of vibration of the ether, or the nature
of the retina, could be altered, the marble would seem not red, but some
other colour. There are many people who are what are called colourblind,
being unable to distinguish one colour from another. Such an one might
declare our marble to be green; and he would be quite as right in saying
that it is green, as we are in declaring it to be red. But then, as the
marble cannot, in itself, be both green and red, at the same time, this
shows that the quality "redness" must be in our consciousness and not in
the marble.
In like manner, it is easy to see that the roundness and the hardness
are forms of our consciousness, belonging to the groups which we call
sensations of sight and touch. If the surface of the cornea were
cylindrical, we should have a very different notion of a round body from
that which we possess now; and if the strength of the fabric, and the
force of the muscles, of the body were increased a hundredfold, our
marble would seem to be as soft as a pellet of bread crumbs.
Not only is it obvious that all these qualities are in us, but, if you
will make the attempt, you will find it quite impossible to conceive of
"blueness," "roundness," and "hardness" as existing without reference to
some such consciousness as our own. It may seem strange to say that even
the "singleness" of the marble is relative to us; but extremely simple
experiments will show that such is veritably the case, and that our two
most trustworthy senses may be made to contradict one another on this
very point. Hold the marble between the finger and thumb, and look at it
in the ordinary way. Sight and touch agree that it is single. Now
squint, and sight tells you that there are two marbles, while touch
asserts that there is only one. Next, return the eyes to their natural
position, and, having crossed the forefinger and the middle finger, put
the marble between their tips. Then touch will declare that there are
two marbles, while sight says that there is only one; and touch claims
our belief, when we attend to it, just as imperatively as sight does.
But it may be said, the marble takes up a certain space which could not
be occupied, at the same time, by anything else. In other words, the
marble has the primary quality of matter, extension. Surely this quality
must be in the thing, and not in our minds? But the reply must still be;
whatever may, or may not, exist in the thing, all that we can know of
these qualities is a state of consciousness. What we call extension is a
consciousness of a relation between two, or more, affections of the
sense of sight, or of touch. And it is wholly inconceivable that what
we call extension should exist independently of such consciousness as
our own. Whether, notwithstanding this inconceivability, it does so
exist, or not, is a point on which I offer no opinion.
Thus, whatever our marble may be in itself, all that we can know of it
is under the shape of a bundle of our own consciousnesses.
Nor is our knowledge of anything we know or feel more, or less, than a
knowledge of states of consciousness. And our whole life is made up of
such states. Some of these states we refer to a cause we call "self;"
others to a cause or causes which may be comprehended under the title of
"not-self." But neither of the existence of "self," nor of that of
"not-self," have we, or can we by any possibility have, any such
unquestionable and immediate certainty as we have of the states of
consciousness which we consider to be their effects. They are not
immediately observed facts, but results of the application of the law of
causation to those facts. Strictly speaking, the existence of a "self"
and of a "not-self" are hypotheses by which we account for the facts of
consciousness. They stand upon the same footing as the belief in the
general trustworthiness of memory, and in the general constancy of the
order of nature--as hypothetical assumptions which cannot be proved, or
known with that highest degree of certainty which is given by immediate
consciousness; but which, nevertheless, are of the highest practical
value, inasmuch as the conclusions logically drawn from them are always
verified by experience.
This, in my judgment, is the ultimate issue of Descartes' argument; but
it is proper for me to point out that we have left Descartes himself
some way behind us. He stopped at the famous formula, "I think,
therefore I am." But a little consideration will show this formula to be
full of snares and verbal entanglements. In the first place, the
"therefore" has no business there. The "I am" is assumed in the "I
think," which is simply another way of saying "I am thinking." And, in
the second place, "I think" is not one simple proposition, but three
distinct assertions rolled into one. The first of these is, "something
called I exists;" the second is, "something called thought exists;" and
the third is, "the thought is the result of the action of the I."
Now, it will be obvious to you, that the only one of these three
propositions which can stand the Cartesian test of certainty is the
second. It cannot be doubted, for the very doubt is an existent thought.
But the first and third, whether true or not, may be doubted, and have
been doubted. For the assertor may be asked, How do you know that
thought is not self-existent; or that a given thought is not the effect
of its antecedent thought, or of some external power? And a diversity of
other questions, much more easily put than answered. Descartes,
determined as he was to strip off all the garments which the intellect
weaves for itself, forgot this gossamer shirt of the "self;" to the
great detriment, and indeed ruin, of his toilet when he began to clothe
himself again.
But it is beside my purpose to dwell upon the minor peculiarities of the
Cartesian philosophy. All I wish to put clearly before your minds thus
far, is that Descartes, having commenced by declaring doubt to be a
duty, found certainty in consciousness alone; and that the necessary
outcome of his views is what may properly be termed Idealism; namely,
the doctrine that, whatever the universe may be, all we can know of it
is the picture presented to us by consciousness. This picture may be a
true likeness--though how this can be is inconceivable; or it may have
no more resemblance to its cause than one of Bach's fugues has to the
person who is playing it; or than a piece of poetry has to the mouth and
lips of a reciter. It is enough for all the practical purposes of human
existence if we find that our trust in the representations of
consciousness is verified by results; and that, by their help, we are
enabled "to walk surefootedly in this life."
Thus the method, or path which leads to truth, indicated by Descartes,
takes us straight to the Critical Idealism of his great successor Kant.
It is that Idealism which declares the ultimate fact of all knowledge to
be a consciousness, or, in other words, a mental phenomenon; and
therefore affirms the highest of all certainties, and indeed the only
absolute certainty, to be the existence of mind. But it is also that
Idealism which refuses to make any assertions, either positive or
negative, as to what lies beyond consciousness. It accuses the subtle
Berkeley of stepping beyond the limits of knowledge when he declared
that a substance of matter does not exist; and of illogicality, for not
seeing that the arguments which he supposed demolished the existence of
matter were equally destructive to the existence of soul. And it refuses
to listen to the jargon of more recent days about the "Absolute," and
all the other hypostatized adjectives, the initial letters of the names
of which are generally printed in capital letters; just as you give a
Grenadier a bearskin cap, to make him look more formidable than he is by
nature.