13. But still, though Endosmose may account in part for

absorption in some cases, it is certain that there is some

other vital force at work in this process. There must be, as

Müller says[80\9], 'an organic attraction of a kind hitherto

unknown.' 'If absorption,' he adds[81\9], is to be explained

in a manner analogous to {213} the laws of endosmose, it

must be supposed that a chemical affinity, resulting from

the vital process itself, is exerted between the chyme in

the intestines and the chyle in the lacteals, by which the

chyle is enabled to attract the chyme without being itself

attracted by it. But such affinity or attraction would be of

a vital nature, since it does not exist after death.'

[Note 80\9: _Physiology_, p. 299.]

[Note 81\9: _Ib._ p. 301.]

14. If the force of absorption be thus mysterious in its

nature, the force of _Secretion_ is still more so. In this

case we have an organ filled with a fine net-work of

blood-vessels, and in the cavities of some _gland_, or open

part, we have a new fluid formed, of a kind altogether

different from the blood itself. It is easily shown that

this cannot be explained by any action of pores or capillary

tubes. But what conception can we form of the forces by

which such a change is produced? Here, again, I shall borrow

the expressions of Müller, as presenting the last result of

modern physiology. He says[82\9], 'The more probable

supposition is, that by virtue of imbibition, or the general

organic porosity, the fluid portion of the blood becomes

diffused through the tissue of the secreting organ; that the

external surface of the glandular canals exerts a chemical

attraction on the elements of the fluid, infusing into them

at the same time a tendency to unite in new combinations;

and then repels them in a manner which is certainly quite

inexplicable, towards the inner surface of the secreting

membrane, or glandular canals.' 'Although quite unsupported

by facts,' he adds, 'this theory of attraction and repulsion

is not without its analogy in physical phenomena; and it

would appear that very similar powers effect the elimination

of the fluid in secretion, and cause it to be taken up by

the lymphatics in absorption.' He elsewhere says[83\9],

'Absorption seems to depend on an attraction the nature of

which is unknown, but of which the very counterpart, as it

were, takes place in secretion; the fluids altered by the

secreting action being repelled towards the free side or

open surface only of the {214} secreting membranes, and then

pressed forwards by the successive portions of the fluids

secreted.'

[Note 82\9: _Physiology_, p. 464.]

[Note 83\9: _Ib._ p. 301.]

15. With regard to the forces which produce the _Motion_ of

absorbed or secreted fluids along their destined course, it

may be seen, from the last quoted sentence, that the same

vital force which changes the nature, also produces the

movement of the substance. The fluids are pressed forwards

by the successive portions absorbed or secreted. That this

is the sole cause, or at least a very powerful cause, of the

motion of the nutritive fluids in organic bodies, is easily

shown by experience. It is found[84\9] that the organs which

effect the ascent of the sap in trees during the spring are

the terminal parts of the roots; that the whole force by

which the sap is impelled upwards is the _vis a tergo_, as

it has been called, the force pushing from behind, exerted

in the roots. And thus the force which produces this motion

is exerted exactly at those points where the organic body

selects from the contiguous mass those particles which it

absorbs and appropriates. And the same may most probably be

taken for the cause of the motion of the lymph and chyle; at

least, Müller says[85\9] that no other motive power has been

detected which impels those fluids in their course.

[Note 84\9: Müller, p. 300.]

[Note 85\9: _Ib._ p. 254.]

Thus, though we must confess the Vital Force concerned in

Assimilation and Secretion to be unknown in its nature, we

still obtain a view of some of the attributes which it

involves. It has mechanical efficacy, producing motions,

often such as would require great mechanical force. But it

exerts at the same point both an attraction and a repulsion,

attracting matter on one side, and repelling it on the

other; and in this circumstance it differs entirely from

mechanical forces. Again, it is not only mechanical but

chemical, producing a complete change in the nature of the

substance on which it acts; to which we must add that the

changes produced by the vital forces are such as, for the

most part, our artificial chemistry {215} cannot imitate.

But, again, by the action of the vital force at any point of

an organ, not only are fluids made to pass, and changed as

they pass, but the organ itself is maintained and

strengthened, so as to continue or to increase its

operation: and thus the vital energy supports its activity

by its action, and is augmented by being exerted.

We have thus endeavoured to obtain a view of some of the

peculiar characters which belong to the Force of Organic

Assimilation;--the Force by which life is kept up, conceived

in the most elementary form to which we can reduce it by

observation and contemplation. It appears that it is a force

which not only produces motion and chemical change, but also

_vitalizes_ the matter on which it acts, giving to it the

power of producing like changes on other matter, and so on

indefinitely. It not only circulates the particles of

matter, but puts them in a stream of which the flow is

development as well as movement.

The force of Organic Assimilation being thus conceived, it

becomes instructive to compare it with the force concerned

in Generation, which we shall therefore endeavour to do.

SECT. IV.--_Attempts to conceive the Process of Generation._

16. At first sight the function of Nutrition appears very

different from the function of Generation. In the former

case we have merely the existing organs maintained or

enlarged, and their action continued; in the latter, we have

a new individual produced and extricated from the parent.

The term _Reproduction_ has, no doubt, been applied, by

different writers, to both these functions;--to the

processes by which an organ when mutilated, is restored by

the forces of the living body, and to the process by which a

new generation of individuals is produced which may be

considered as taking the place of the old generation, as

these are gradually removed by death. But these are

obviously different senses of the word. In the latter case,

the {216} term _Reproduction_ is figuratively used; for the

_same_ individuals are not reproduced; but the species is

kept up by the propagation of new individuals, as in

nutrition the organ is kept up by the assimilation of new

matter. To escape ambiguity, I shall avoid using the term

_Reproduction_ in the sense of _Propagation_.

17. In Nutrition, as we have seen, the matter, which from

being at first extraneous, is appropriated by the living

system, and directed to the sustentation of the organs,

undergoes a series of changes of which the detail eludes our

observation and apprehension. The nutriment which we receive

contributes to the growth of flesh and bone, viscera and

organs of sense. But we cannot trace in its gradual changes

a visible preparation for its final office. The portion of

matter which is destined to repair the waste of the eye or

the skin, is not found assuming a likeness to the parts of

the eye or the structure of the skin, as it comes near the

place where it is moulded into its ultimate form. The new

parts are insinuated among the old ones, in an obscure and

imperceptible matter. We can trace their progress only by

their effects. The organs _are_ nourished, and that is

almost all we can learn: we cannot discover _how_ this is

done. We cannot follow nature through a series of manifest

preparations and processes to this result.

18. In Generation the case is quite different. The young

being is formed gradually and by a series of distinguishable

processes. It is included within the parent before it is

extruded, and approaches more or less to the likeness of the

parent before it is detached. While it is still an embryo,

it shares in the nutriment which circulates through the

system of the mother; but its destination is already clear.

While the new and the old parts, in every other portion of

the mother, are undistinguishably mixed together, this new

part, the fœtus, is clearly distinct from the rest of the

system, and becomes rapidly more and more so, as the time

goes on. And thus there is formed, not a new part, but a new

whole; it is not an organ which is kept up, but an offspring

which is prepared. The progeny is {217} included in the

parent, and is gradually fitted to be separated from it. The

young is at first only the development of a part of the

organization of the mother;--of a germ, an ovule. But it is

not developed like other organs, retaining its general form.

It does not become merely a larger bud, a larger ovule; it

is entirely changed; it becomes--from a bud--a blossom, a

flower, a fruit, a seed; from an ovule it becomes an egg, a

chick, a bird; or it may be, a fœtus, a child. The original

rudiment is not merely nourished, but unfolded and

transformed through the most marked and remote changes,

gradually tending to the form of the new individual.

19. But this is not all. The fœtus is, as we have said, a

development of a portion of the mother's organization. But

the fœtus (supposing it female) is a likeness of the mother.

The mother, even before conception, contains within herself

the germs of her progeny; the female fœtus, therefore, at a

certain stage of development, will contain also the germs of

possible progeny; and thus we may have the germs of future

generations, pre-existing and included successively within

one another. And this state of things, which thus suggests

itself to us as possible, is found to be the case in facts

which observation supplies. Anatomists have traced ovules in

the unborn fœtus, and thus we have three generations

included one within another.

20. Supposing we were to stop here, the process of

propagation might appear to be altogether different from

that of nutrition. The latter, as we have seen, may be in

some measure illustrated by the image of a _vortex_; the

former has been represented by the image of a series of

germs, _sheathed_ one within another successively, and this

without any limit. This view of the subject has been termed

the doctrine of the _Pre-existence of germs_; and has been

designated by German writers by a term 'Einschachtelungs-theorie'

descriptive of the successive sheathing of which I have

spoken. Imitating this term, we may call it _the Theory of

successive inclusion_. It has always had many {218}

adherents; and has been, perhaps, up to the present time,

the most current opinion on the subject of generation.

Cuvier inclines to this opinion[86\9]. 'Fixed forms

perpetuating themselves by generation distinguish the

species of living things. These forms do not produce

themselves, do not change themselves. Life supposes them to

exist already; its flame can be lighted only in organization

previously prepared; and the most profound meditations and

the most delicate researches terminate alike in the mystery

of the _pre-existence of germs_.'

[Note 86\9: _Règne Animal_, p. 20.]

21. Yet this doctrine is full of difficulty. It is, as

Cuvier says, a mysterious view of the subject;--so

mysterious, that it can hardly be accepted by us, who seek

distinct conceptions as the basis of our philosophy. Can it

be true, not only that the germ of the offspring is

originally included in the parent, but also the germs of

_its_ progeny, and so on without limit:--so that each

fruitful individual contains in itself an infinite

collection of future possible individuals;--a reserve of

infinite succeeding generations? This is hard to admit. Have

we no alternative? What is the opposite doctrine?

22. The opposite doctrine deserves at least some notice. It

extends, to the production of a new individual, the

conception of growth by nutrition. According to this view,

we suppose propagation to take place, not as in the view

just spoken of, by inclusion and extrusion, but by

assimilation and development;--not by the material

pre-existence of germs, but by the communication of vital

forces to new matter. This opinion appears to be entertained

by some of the most eminent physiologists of the present

time. Thus, Müller says, 'The organic force is also

creative. The organic force which resides in the whole, and

on which the existence of each part depends, has also the

property of generating, from organic matter, the parts

necessary to the whole.' Life, he adds, is not merely a

harmony of the {219} parts. On the contrary, the harmonious

action of the parts subsists only by the influence of a

force pervading all parts of the body. 'This force exists

before the harmonizing parts, which are in fact formed by it

during the development of the embryo.' And again; 'The

creative force exists in the germ, and creates in it the

essential force of the future animal. The germ is

_potentially_ the whole animal: during the development of

the germ the parts which constitute the actual whole are

produced.'

23. In this view, we extend to the reproduction of an

individual the same conception of organic assimilation which

we have already arrived at, as the best notion we can form

of the force by which the reproduction and sustentation of

parts takes place. And is not such an extension really very

consistent? If a living thing can appropriate to itself

extraneous matter, invest it with its own functions, and

thus put it in the stream of constant development, may we

not conceive the development of a new _whole_ to take place

in this way as well as of a _part_? If the organized being

can infuse into new matter its vital forces, is there any

contradiction in supposing this infusion to take place in

the full measure which is requisite for the production of a

new individual? The force of organic assimilation is

transferred to the very matter on which it acts; it may be

transferred so that the operation of the forces produces not

only an organ, but a system of organs.

24. This identification of the forces which operate in

Nutrition and Generation may at first seem forced and

obscure, in consequence of the very strong apparent

differences of the two processes which we have already

noticed. But this defect in the doctrine is remedied by the

consideration of what may be considered as intermediate

cases. It is not true that, in the nutrition of special

organs, the matter is always conveyed to its ultimate

destination without being on its way moulded into the form

which it is finally to bear, as the embryo is moulded into

the form of the {220} future individual. On the contrary,

there are cases in which the waste of the organs is supplied

by the growth of new ones, which are prepared and formed

before they are used, just as the offspring is prepared and

formed before it is separated from the parent. This is the

case with the teeth of many animals, and especially with the

teeth of animals of the crocodile kind. Young teeth grow

near the root of the old ones, like buds on the stem of a

plant; and as these become fully developed, they take the

place of the parent tooth when that dies and is cast away.

And these new teeth in their turn are succeeded by others

which germinate from them. Several generations of such

teeth, it is said as many as four, have been detected by

anatomists, visibly existing at the same time; just as

several generations of germs of individuals have been, as we

already stated, observed included in one another. But this

case of the teeth appears to show very strikingly how

insufficient such observations are to establish the doctrine

of successive inclusion, or of the pre-existence of germs.

Are we to suppose that every crocodile's tooth includes in

itself the germs of an infinite number of possible teeth, as

in the theory of pre-existing germs every individual

includes an infinite number of individuals? If this be true

of teeth, we must suppose that organ to follow laws entirely

different from almost every other organ; for no one would

apply to the other organs in general such a theory of

reproduction. But if such a theory be not maintained

respecting the teeth, how can we maintain the theory of the

pre-existing germs of individuals, which has no

recommendation except that of accounting for exactly the

same phenomena?

It would seem, then, that we are, by the closest

consideration of the subject, led to conceive the forces by

which generation is produced, as forces which vitalize

certain portions of matter, and thus prepare them for

development according to organic forms; and thus the

conception of this Generative Force is identified with the

conception of the Force of Organic Assimilation, to {221}

which we were led by the consideration of the process of

nutrition.

I shall not attempt to give further distinctness and fixity

to this conception of one of the vital forces; but I shall

proceed to exemplify the same analysis of life by some

remarks upon another Vital Process, and the Forces of which

it exhibits the operation.

{{222}}

CHAPTER V.

ATTEMPTS TO FORM IDEAS OF SEPARATE VITAL FORCES,

_continued_.--VOLUNTARY MOTION.

1. WE formerly noticed the distinctions of _organic_ and

_animal_ functions, organic and animal forces, as one of the

most marked distinctions to which physiologists have been

led in their analysis of the vital powers. I have now taken

one of the former, the _organic_ class of functions, namely,

Nutrition; and have endeavoured to point out in some measure

the peculiar nature of the vital forces by which this

function is carried on. It may serve to show the extent and

the difficulty of this subject, if, before quitting it, I

offer a few remarks suggested by a function belonging to the

other class, the _animal_ functions. This I shall briefly do

with respect to _Voluntary Motion_.

2. In the History of Physiology, I have already related the

progress of the researches by which the organs employed in

voluntary motion became known to anatomists. It was

ascertained to the satisfaction of all physiologists, that

the immediate agents in such motion are the muscles; that

the muscles are in some way contracted, when the nerves

convey to them the agency of the will; and that thus the

limbs are moved. It was ascertained, also, that the nerves

convey sensations from the organs of sense inwards, so as to

make these sensations the object of the animal's

consciousness. In man and the higher animals, these

impressions upon the nerves are all conveyed to one internal

organ, the brain; and from this organ all impressions of the

will appear to proceed; and thus the brain is {223} the

center of animal life, towards which sensations converge,

and from which volitions diverge.

But this being the process, we are led to inquire how far we

can obtain any knowledge, or form any conception, of the

vital forces by means of which the process is carried on.

And here I have further stated in the History[87\9], that

the transfer of sensations and volitions along the nerves

was often represented as consisting in the motion of a

Nervous Fluid. I have related that the hypothesis of such a

fluid, conveying its impressions either by motions of

translation or of vibration, was countenanced by many great

names, as Newton, Haller, and even Cuvier. But I have

ventured to express my doubt whether this hypothesis can

have much value: 'for,' I have said, 'this principle cannot

be mechanical, chemical, or physical, and therefore cannot

be better understood by embodying it in a fluid. The

difficulty we have in conceiving what the force _is_, is not

got rid of by explaining the machinery by which it is

_transferred_.'

[Note 87\9: _Hist. Ind. Sc._ b. xvii. c. v. s. 2.]

3. I may add, that no succeeding biological researches

appear to have diminished the force of these considerations.

In modern times, attempts have repeatedly been made to

identify the nervous fluid with electricity or galvanism.

But these attempts have not been satisfactory or conclusive

of the truth of such an identity: and Professor Müller

probably speaks the judgment of the most judicious

physiologists, when he states it as his opinion, after

examining the evidence[88\9], 'That the vital actions of the

nerves are not attended with the development of any galvanic

currents which our instruments can detect; and that the laws

of action of the nervous principle are totally different

from those of electricity.'

[Note 88\9: _Elem. Phys._ p. 640.]

That the powers by which the nerves are the instruments of

sensation, and the muscles of motion, are vital endowments,

incapable of being expressed or explained by any comparison

with mechanical, chemical, and electrical forces, is the

result which we should {224} expect to find, judging from

the whole analogy of science; and which thus is confirmed by

the history of physiology up to the present time. We

naturally, then, turn to inquire whether such peculiar vital

powers have been brought into view with any distinctness and

clearness.

4. The property by which muscles, under proper stimulation,

contract and produce motion, has been termed _Irritability_

or _Contractility_; the property by which nerves are

susceptible of their appropriate impressions has been termed

_Sensibility_. A very few words on each of these subjects

must suffice.

_Irritability._--I have, in the History of Physiology[89\9],

noticed that Glisson, a Cambridge professor, distinguished

the Irritation of muscles as a peculiar property, different

from any merely mechanical or physical action. I have

mentioned, also, that he divides Irritation into _natural_,

_vital_, and _animal_; and points out, though briefly, the

graduated differences of Irritability in different organs.

Although these opinions did not at first attract much

notice, about seventy years afterwards attention was

powerfully called to this vital force, _Irritability_, by

Haller. I shall borrow Sprengel's reflections on this subject.

[Note 89\9: _Hist. Ind. Sc._ b. xvii. c. v.]

'Hitherto men had been led to see more and more clearly that

the cause of the bodily functions, the fundamental power of

the animal frame, is not to be sought in the mechanism, and

still less in the mixture of the parts. In this conviction,

they had had recourse partly to the quite supersensuous

principle of the Soul, partly to the half-material principle

of the Animal Spirits, in order to explain the bodily

motions. Glisson alone saw the necessity of assuming an

Original Power in the fibres, which, independent of the

influence of the animal spirits, should produce contraction

in them. And Gorter first held that this Original Power was

not to be confined to the muscles, but to be extended to all

parts of the living body. {225}

'But as yet the laws of this Power were not known, nor had

men come to an understanding whether it were fully distinct

from the elasticity of the parts, or by what causes it was

put in action. They had neither instituted observations nor

experiments which established its relation to other assumed

forces of the body. There was still wanting a determination

of the peculiar seat of this power, and experiments to trace

its gradual differences in different parts of the body. In

addition to other causes, the necessity of the assumption of

such a power was felt the more, in consequence of the

prevalence of Leibnitz's doctrine of the activity of matter;

but it was an occult quality, and remained so till Haller,

by numerous experiments and solid observations, placed in a

clear light the peculiarities of the powers of the animal body.'

5. Perhaps, however, Haller did more in the way of

determining experimentally the limits and details of the

application of this idea of Irritability as a peculiar

attribute, than in developing the Idea itself. In that way

his merits were great. As early as the year 1739, he

published his opinion upon Irritability as the cause of

muscular motion, which he promulgated again in 1743. But

from the year 1747 he was more attentive to the

peculiarities of Irritability, and its difference from the

effect of the nerves. In the first edition of his

_Physiology_, which appeared in 1747, he distinguished three

kinds of Force in muscles,--the Dead Force, the Innate

Force, and the Nervous Power. The first is identical with

the elastic force of dead matter, and remains even after

death. The _innate force_ continues only a short time after

death, and discloses itself especially by alternate

oscillations; the motions which arise from this are much

more lively than those which arise from mere elasticity:

they are not excited by tension, nor by pressure, nor by any

mechanical alteration, but only by _irritation_. The

_nervous force_ of the muscle is imparted to it from without

by the nerves; it preserves the _irritability_, which cannot

long subsist without the influence of the nervous force, but

is not identical with it. {226}

In the year 1752, Haller laid before the Society of

Göttingen the result of one hundred and ninety experiments;

from which it appears to what parts of the animal system

Irritability and Nervous Power belong. These I need not

enumerate. He also investigated with care its gradations in

those parts which do possess it. Thus the heart possesses it

in the highest degree, and other organs follow in their

order.

6. Haller's doctrine was, that there resides in the muscles

a peculiar vital power by which they contract, and that this

power is distinct from the attributes of the nerves. And

this doctrine has been accepted by the best physiologists of

modern times. But this distinction of the _irritability_ of

the muscles from the _sensibility_ of the nerves became

somewhat clearer by giving to the former attribute the name

of _Contractility_. This accordingly was done; it is, for

example, the phraseology used by Bichat. By speaking of

_animal sensibility_ and _animal contractility_, the passive

and the active element of the processes of animal life are

clearly separated and opposed to each other. The sensations

which we feel, and the muscular action which we exert, may

be closely and inseparably connected, yet still they are

clearly distinguishable. We can easily in our apprehension

separate the titillation felt in the nose on taking snuff,

from the action of the muscles in sneezing; or the

perception of an object falling towards the eye, from the

exertion which shuts the eye-lid; although in these cases

the passive and active part of the process are almost or

quite inseparable in fact. And this clear separation of the

active from the passive power is something, it would seem,

peculiar to the Animal Vital Powers; it is a character by

which they differ, not only from mechanical, chemical, and

all other merely physical forces, but even from Organic

Vital Powers.

7. But this difference between the Animal and the Organic

Vital Powers requires to be further insisted upon, for it

appears to have been overlooked or denied by very eminent

physiologists. For instance, Bichat classifies the Vital

Powers as Animal Sensibility, {227} Animal Contractility,

Organic Sensibility, Organic Contractility.

Now the view which suggests itself to us, in agreement with

what has been said, is this:--that though Animal Sensibility

and Animal Contractility are clearly and certainly distinct,

Organic Sensibility and Organic Contractility are neither

separable in fact nor in our conception, but together make

up a single Vital Power. That they are not separable in fact

is, indeed, acknowledged by Bichat himself. 'The organic

contractility,' he says[90\9], 'can never be separated from

the sensibility of the same kind; the reaction of the

excreting tubes is immediately connected with the action

which the secreted fluids exercise upon them: the

contraction of the heart must necessarily succeed the influx

of the blood into it.' It is not wonderful, therefore, that

it should have happened, as he complains, that 'authors have

by no means separated these two things, either in their

consideration or in language.' We cannot avoid asking, Are

Organic Sensibility and Organic Contractility really

anything more than two different aspects of the same thing,

like action and reaction in mechanics, which are only two

ways of considering the action which takes place at a point;

or like the positive and negative electricities, which, as

we have seen, always co-exist and correspond to each other?

[Note 90\9: _Life and Death_, p. 94.]

8. But we may observe, moreover, that Bichat, by his use of

the term Contractility, includes in it powers to which it

cannot with any propriety be applied. Why should we suppose

that the vital powers of absorption, secretion,

assimilation, are of such a nature that the name

_contractility_ may be employed to describe them? We have

seen, in the last chapter, that the most careful study of

these powers leads us to conceive them in a manner

altogether removed from any notion of contraction. Is it not

then an abuse of language which cannot possibly lead to

anything but {228} confusion, to write thus[91\9]: 'The

insensible organic contractility is that, by virtue of which

the excreting tubes react upon their respective fluids, the

secreting organs upon the blood which flows into them, the

parts where nutrition is performed upon the nutritive

juices, and the lymphatics upon the substances which excite

their open extremities'? In the same manner he

ascribes[92\9] to the peculiar sensibility of each organ the

peculiarity of its products and operations. An increased

absorption is produced by an increased susceptibility of the

'absorbent orifices.' And thus, in this view, each organic

power may be contemplated either as sensibility or as

contractility, and may be supposed to be rendered more

intense by magnifying either of these its aspects; although,

in fact, neither can be conceived to be increased without an

exactly commensurate increase of the other.

[Note 91\9: _Life and Death_, p. 95.]

[Note 92\9: _Ib._ p. 90.]

9. This opinion, unfounded as it thus appears to be, that

all the different organic vital powers are merely different

kinds of Contractility or Excitability, was connected with

the doctrines of Brown and his followers, which were so

celebrated in the last century, that all diseases arise from

increase or from diminution of the Vital Force. The

considerations which have already offered themselves would

lead us to assent to the judgment which Cuvier has

pronounced upon this system. 'The theory of excitation,' he

says, 'so celebrated in these later times by its influence

upon pathology and therapeutick, is at bottom only a

modification of that, in which, including under a common

name Sensibility and Irritability,' and we may add, applying

this name to all the Vital Powers, 'the speculator takes

refuge in an abstraction so wide, that if, by it, he

simplifies medicine, he by it annihilates all positive

physiology[93\9].'

[Note 93\9: _Hist. des Sc. Nat. depuis_ 1789, i. 219.]

10. The separation of the nervous influence and the muscular

irritability, although it has led to many highly instructive

speculations, is not without its {229} difficulties, when

viewed with reference to the Idea of Vital Power. If the

irritability of each muscle reside in the muscle itself, how

does it differ from a mere mechanical force, as elasticity?

But, in point of fact, it is certain that the muscular

irritability of the animal body is not an attribute of the

muscle itself independent of its connexion with the system.

No muscle, or other part, removed from the body, _long_

preserves its irritability. This power cannot subsist

permanently, except in connexion with an organic whole. This

condition peculiarly constitutes irritability a _living_

force: and this condition would be satisfied by considering

the force as derived from the nervous system; but it appears

that though the nervous system has the most important

influence upon all vital actions, the muscular irritability

must needs be considered as something distinct. And thus the

Irritability or Contractility of the muscle is a peculiar

endowment of the texture, but it is at the same time an

endowment which can only co-exist with life; it is, in

short, a peculiar Vital Power.

11. This necessity of the union of the muscle with the whole

nervous system, in order that it may possess irritability,

was the meaning of the true part of Stahl's psychical

doctrine; and the reason why he and his adherents persisted

in asserting the power of the soul even over involuntary

motions. This doctrine was the source of much controversy in

later times.

'But,' says Cuvier[94\9], 'this opposition of opinion may be

reconciled by the intimate union of the nervous substance

with the fibre and the other contractile organic elements,

and by their reciprocal action;--doctrines which had been

presented with so much probability by physiologists of the

Scotch school, but which were elevated above the rank of

hypotheses only by the observations of more recent times.

[Note 94\9: _Hist. des Sc. Nat. depuis_ 1789, i. 213.]

'The fibre does not contract by itself, but by the influence

of the nervous filaments, which are always united with it.

The change which produces the {230} contraction cannot take

place without the concurrence of both these substances; and

it is further necessary that it should be occasioned each

time by an exterior cause, by a stimulant.

'The Will is one of these stimulants; but it only excites

the Irritability, it does not constitute it; for in the case

of persons paralytic from apoplexy, the Irritability

remains, though the power of the Will over it is gone. Thus

_irritability_ depends in part on the _nerve_, but not on

the _sensibility_: this last is another property, still more

admirable and occult than the irritability; but it is only

one among several functions of the nervous system. It would

be an abuse of words to extend this denomination to

functions unaccompanied by perception.'

12. Supposing, then, that Contractility is established as a

peculiar Vital Power residing in the muscles, we may ask

whether we can trace with any further exactness the seat and

nature of this power. It would be unsuitable to the nature

of the present work to dwell upon the anatomical discussions

bearing upon this point. I will only remark that some

anatomists maintain[95\9] that muscles are contracted by

those fibres assuming a zigzag form, which at first were

straight. Others (Professor Owen and Dr. A. Thompson) doubt

the accuracy of this observation; and conceive that the

muscular fibre becomes shorter and thicker, but does not

deviate from a right line. We may remark that the latter

kind of action appears to be more elementary in its nature.

We can, as a matter of geometry, conceive a straight line

thrown into a zigzag shape by muscular contractions taking

place between remote parts of it; but it is difficult to

conceive by what _elementary_ mode of action a straight

fibre could bend itself at certain points, and at certain

points only; since the elementary force must act at every

point of the fibre, and not at certain selected points.

[Note 95\9: Müller, _Elem. Phys._ p. 887.]

13. A circumstance which remarkably marks the difference

between the vital force of Contractility, {231} inherent in

muscles, and any merely dead or mechanical force, is this;

that in assuming their contractile state, muscles exert a

tension which they could not themselves support or convey if

not strengthened by their vital irritability. They are

capable of raising weights by their exertion, which will

tear them asunder when the power of contraction is lost by

death. This has induced Cuvier and other physiologists[96\9]

to believe 'that in the moment of action, the particles that

compose a fibre, not only approach towards each other

longitudinally, but that their cohesive attraction becomes

instantaneously much greater than it was before: for without

such an increase of cohesive force, the tendency to shorten

could not, as it would appear, prevent the fibre from being

torn.' We see here the difficulty, or rather the

impossibility, of conceiving muscular contractility as a

mere mechanical force; and perhaps there is little hope of

any advantage by calling in the aid of chemical hypothesis

to solve the mechanical difficulty. Cuvier conjectures that

a sudden change in the chemical composition may thus so

quickly and powerfully augment the cohesion. But we may ask,

are not a chemical synthesis and analysis, suddenly

performed by a mere act of the will, as difficult to

conceive as a sudden increase and decrease of mechanical

power directly produced by the same cause?

[Note 96\9: Prichard, _Vital Prin._ p. 126.]

14. _Sensibility._ The nerves are the organs and channels of

Sensibility. By means of them we receive our sensations,

whether of mere pleasure and pain, or of qualities which we

ascribe to external objects, as a bitter taste, a sweet

odour, a shrill sound, a red colour, a hard or a hot feeling

of touch. Some of these sensations are but obscurely the

objects of our consciousness; as for example the feeling

which our feet have of the ground, or the sight which our

eyes have of neighbouring objects, when we walk in a

reverie. In these cases the sensations, though obscure,

exist; for they {232} serve to balance and guide us as we

walk. In other cases, our sensations are distinctly and

directly the objects of our attention.

But our Sensations, as we have already said, we ascribe as

Qualities to external objects. By our senses we perceive

objects, and thus our _sensations_ become _perceptions_. We

have not only the sensation of _round_, _purple_, and

_green_, repeated and varied, but the perception of a _bunch

of grapes_ partly ripe and partly unripe. We have not only

sensations of noise and of variously-coloured specks rapidly

changing their places, but we have perceptions, by sound and

sight, of a stone rolling down the hill and crushing the

shrubs in its path. We scarcely ever dwell upon our

Sensations; our thoughts are employed upon Objects. We

regard the impressions upon our nerves, not for what they

_are_, but for what they _tell_ us.

But in what Language do the impressions upon the nerves thus

speak to us of an external world,--of the forms and

qualities and actions of objects? How is it that by the aid

of our nervous system we become acquainted not only with

impressions but with _things_; that we learn not only the

relation of objects to us, but to one another?

15. It has been shown at some length in the previous Books,

that the mode in which Sensations are connected in our minds

so as to convey to us the knowledge of Objects and their

Relations, is by being contemplated with reference to

_Ideas_. Our Sensations, connected by the Idea of Space,

become Figures; connected by the Idea of Time, they become

Causes and Effects; connected by the Idea of Resemblance,

they become Individuals and Kinds; connected by the Idea of

Organization, they become Living Things. It has been shown

that without these Ideas there can be no connexion among our

sensations, and therefore no perception of Figure, Action,

Kind, or in short, of bodies under any aspect whatever.

Sensations are the rude _Matter_ of our perceptions; and are

nothing, except so far as they have _Form_ given them by

Ideas. {233} But thus moulded by our Ideas, Sensation

becomes the source of an endless store of important

Knowledge of every possible kind.

16. But one of the most obvious uses of our perceptions and

our knowledge is to direct our Actions. It is suitable to

the condition of our being that when we perceive a bunch of

grapes, we should be able to pluck and eat the ripe ones;

that when we perceive a stone rushing down the side of a

hill, we should be able to move so as to avoid it. And this

must be done by moving our limbs; in short, by the use of

our muscles. And thus Sensation leads, not directly, but

through the medium of Ideas, to muscular Contraction. I say

that sensation and Muscular action are in such cases

connected through the medium of Ideas. For when we proceed

to pluck the grape which we see, the _sensation_ does not

determine the motion of the hand by any necessary

geometrical or mechanical conditions, as an impression made

upon a machine determines its motions; but the _perception_

leads us to stretch forth the hand to that part of space,

wherever it is, where we _know_ that the grape is; and this,

not in any determinate path, but, it may be, avoiding or

removing intervening obstacles, which we also _perceive_.

There is in every such case a connexion between the

sensation and the resulting action, not of a material but of

a mental kind. The cause and the effect are bound together,

not by physical but by intellectual ties.

17. And thus in such cases, between the two _vital_

operations, Sensation and Muscular Action, there intervenes,

as an intermediate step, Perception or Knowledge, which is

not merely vital but _ideal_. But this is not all; there is

still another mental part of the process which may be

readily distinguished from that which we have described. An

act of the _Will_, a Volition, is that, in the Mind, which

immediately determines the action of the Muscles of the

Body. And thus Will intervenes between Knowledge and Action;

and the cycle of operations which take place when animals

act with reference to external objects is {234}

this:--Sensation, Perception, Volition, Muscular

Contraction.

18. To attempt further to analyse the mental part of this

cycle does not belong to the present part of our work. But

we may remark here, as we have already remarked in the

History[97\9], how irresistibly we are led by physiological

researches into the domain of thought and mind. We pass from

the body to the soul, from physics to metaphysics; from

biology to psychology; from things to persons; from nouns to

pronouns. I have there noticed the manner in which Cuvier

expresses this transition by the introduction of the

pronoun: 'The impression of external objects upon the ME,

the production of a sensation, of an image, is a mystery

impenetrable to our thoughts.'

[Note 97\9: _Hist. Ind. Sc._ b. xvii. c. v. s. 2.]

19. But to return to the merely biological part of our

speculations. We have arrived, it will be perceived, at this

result: that in animal actions there intervenes between the

two terms of Sensation and Muscular Contraction, an

intermediate process; which may be described as a

communication to and from a Center. The Center is the seat

of the sentient and volent faculties, and is of a

_hyperphysical_ nature. But the existence of such a Center

as a necessary element in the functions of the _animal_ life

is a truth which is important in biology. This indeed may be

taken as the peculiar character of animal, as distinguished

from merely _organic_ powers. Accordingly, it is so stated

by Bichat. For although he superfluously, as I have tried to

show, introduces into his list of vital powers an organic

sensibility, he still draws the distinction of which I have

spoken; 'in the animal life, Sensibility is the faculty of

receiving an Impression _plus_ that of referring it to a

common Center[98\9].'

[Note 98\9: _Life and Death_, p. 84.]

20. But since Sensibility and Contractility are thus

connected by reference to a common Center, we may ask,

before quitting the subject, what are the different forms

which this reference assumes? Is the connexion {235} always

attended by the distinct steps of Knowledge and Will,--by a

clear act of consciousness, as in the case which we have

taken, of plucking a grape; or may these steps become

obscure, or vanish altogether?

We need not further illustrate the _conscious_ connexion.

Such actions as we have described are called _voluntary_

actions. In extreme cases, the mental part of the process is

obvious enough. But we may gradually pass from these to

cases in which the mental operation is more and more obscure.

In walking, in speaking, in eating, in breathing, our

muscular exertions are directed by our sensations and

perceptions: yet in such processes, how dimly are we

conscious of perceptive and directive power! How the mind

should be able to exercise such a power, and yet should be

scarcely or not at all conscious of its exercise, is a very

curious problem. But in all or in most of the instances just

mentioned, the solution of this problem appears to depend

upon psychological rather than biological principles, and

therefore does not belong to this place.

21. But in cases at the other extreme (unconscious actions)

the mental part of the operation vanishes altogether. In

many animals, even after decapitation, the limbs shrink when

irritated. The motions of the iris are determined by the

influence of light on our eyes, without our being aware of

the motions. Here Sensations produce Motions, but with no

trace of intervening Perception or Will. The Sensation

appears to be _reflected_ back from the central element of

animal life, in the form of a Muscular Contraction; but in

this case the Sensation is not modified or regulated by any

_Idea_. These reflected motions have no reference to

relations of space or force among surrounding objects. They

are blind and involuntary, like the movements of convulsion,

depending for direction and amount only on the position and

circumstances of the limb itself with its muscles. Here the

Centre from which the reflection takes place is merely

_animal_, not intellectual.

In this case some physiologists have doubted whether the

reflection of the sensation in the form of a muscular {236}

contraction does really take place from the Center; and have

conceived that sensorial impressions might affect motor

nerves without any communication with the nervous Center.

But on this subject we may, I conceive, with safety adopt

the decision of Professor Müller, deliberately given after a

careful examination of the subject: 'When impressions made

by the action of external stimuli on sensitive nerves give

rise to motions in other parts, these motions are never the

result of the _direct_ reaction of the sensitive and motor

fibres of the nerves on each other; the irritation is

conveyed by the sensitive fibres to the brain and spinal

cord, and is by these communicated to the motor fibres.'

22. Thus we have two extreme cases of the connexion of

sensation with muscular action; in one of which the

connexion clearly _is_, and in the other it as clearly _is

not_, determined by relations of Ideas, in its transit

through the nervous Center. There is another highly curious

case standing intermediate between these two, and extremely

difficult to refer to either. I speak of the case of _Instinct_.

Instinct leads to actions which are _such as if they were

determined by Ideas_. The lamb follows its mother by

instinct; but the motions by which it does this, the special

muscular exertions, depend entirely upon the geometrical and

mechanical relations of external bodies, as the form of the

ground, and the force of the wind. The contractions of the

muscles which are requisite in order that the creature may

obey its instinct, vary with every variation of these

external conditions;--are not determined by any rule or

necessity, but by properties of Space and Force. Thus the

action is not governed by Sensations directly, but by

sensations moulded by Ideas. And the same is the case with

other cases of instinct. The dog hunts by instinct; but he

hunts certain kinds of animals merely, thus showing that his

instinct acts according to Resemblances and Differences; he

crosses the field repeatedly to find the track of his prey

by scent; thus recognizing the relations of Space with

reference to the track; he leaps, adjusting his Force to

{237} the distance and height of the leap with mechanical

precision; and thus he practically recognizes the Ideas of

Resemblance, Space, and Force.

But have animals such Ideas? In any proper sense in which we

can speak of possessing Ideas, it appears plain that they

have not. Animals cannot, at any time, be said properly to

possess ideas, for ideas imply the possibility of

_speculative_ knowledge.

23. But even if we allow to animals only the _practical_

possession of Ideas, we have still a great difficulty

remaining. In the case of man, his ideas are unfolded

gradually by his intercourse with the external world. The

child learns to distinguish forms and positions by a

repeated and incessant use of his hands and eyes; he learns

to walk, to run, to leap, by slow and laborious degrees; he

distinguishes one man from another, and one animal from

another, only after repeated mistakes. Nor can we conceive

this to be otherwise. How should the child know at once what

muscles he is to exert in order to touch with his hand a

certain visible object? How should he know what muscles to

exert that he may stand and not fall, till he has tried

often? How should he learn to direct his attention to the

differences of different faces and persons, till he is

roused by some memory, or hope which implies memory? It

seems to us as if the sensations could not, without

considerable practice, be rightly referred to Ideas of

Space, Force, Resemblance, and the like.

Yet that which thus appears impossible, is in fact done by

animals. The lamb almost immediately after its birth follows

its mother, accommodating the actions of its muscles to the

form of the ground. The chick, just escaped from the shell,

picks up a minute insect, directing its beak with the

greatest accuracy. Even the human infant seeks the breast

and exerts its muscles in sucking, almost as soon as it is

born. Hence, then, we see that Instinct produces at once

actions regulated by Ideas, or, at least, which take place

_as if_ they were regulated by Ideas; although the Ideas

cannot have been developed by exercise, and only appear to

exist so far as such actions are concerned. {238}

24. The term _Instinct_ may properly be opposed to

_Insight_. The former implies an inward principle of action,

implanted within a creature and practically impelling it,

but not capable of being developed into a subject of

contemplation. While the instinctive actions of animals are

directed by such a principle, the deliberate actions of man

are governed by insight: he can contemplate the ideal

relations on which the result of his action depends. He can

in his mind map the path he will follow, and estimate the

force he will exert, and class the objects he has to deal

with, and determine his actions by the relations which he

thus has present to his mind. He thus possesses Ideas not

only practically, but speculatively. And knowing that the

Ideas by which he commonly directs his actions, Space,

Cause, Resemblance, and the like, have been developed to

that degree of clearness in which he possesses them by the

assiduous exercise of the senses and the mind from the

earliest stage of infancy, and that these Ideas are capable

of being still further unfolded into long trains of

speculative truth, he is unable to conceive the manner in

which animals possess such Ideas as their instinctive

actions disclose:--Ideas which neither require to be

unfolded nor admit of unfolding; which are adequate for

practical purposes without any previous exercise, and

inadequate for speculative purposes with whatever labour

cultivated.

I have ventured to make these few remarks on Instinct since

it may, perhaps, justly be considered as the last province

of Biology, where we reach the boundary line of Psychology.

I have now, before quitting this subject, only one other

principle to speak of.

{{239}}

CHAPTER VI.

OF THE IDEA OF FINAL CAUSES.

1. BY an examination of those notions which enter into all

our reasonings and judgments on living things, it appeared

that we conceive animal life as a vortex or cycle of moving

matter in which the form of the vortex determines the

motions, and these motions again support the form of the

vortex: the stationary parts circulate the fluids, and the

fluids nourish the permanent parts. Each portion ministers

to the others, each depends upon the other. The parts make

up the whole, but the existence of the whole is essential to

the preservation of the parts. But parts existing under such

conditions are _organs_, and the whole is _organized_. This

is the fundamental conception of organization. 'Organized

beings,' says the physiologist[99\9], 'are composed of a

number of essential and mutually dependent parts.' 'An

organized product of nature,' says the great

metaphysician[100\9], 'is that in which all the parts are

mutually ends and means.'

[Note 99\9: Müller, _Elem._ p. 18.]

[Note 100\9: Kant, _Urtheilskraft_, p. 296.]

2. It will be observed that we do not content ourselves with

saying that in such a whole, all the parts are _mutually

dependent_. This might be true even of a mechanical

structure; it would be easy to imagine a framework in which

each part should be necessary to the support of each of the

others; for example, an arch of several stones. But in such

a structure, the parts have no properties which they derive

from the whole. They are beams or stones when separate; they

are no more when joined. But the same is not the case in an

organized whole. The limb of an animal separated {240} from

the body, loses the properties of a limb, and soon ceases to

retain even its form.

3. Nor do we content ourselves with saying that the parts

are _mutually causes and effects_. This is the case in

machinery. In a clock, the pendulum by means of the

escapement causes the descent of the weight, the weight by

the same escapement keeps up the motion of the pendulum. But

things of this kind may happen by accident. Stones slide

from a rock down the side of a hill and cause it to be

smooth; the smoothness of the slope causes stones still to

slide. Yet no one would call such a slide an organized

system. The system is organized, when the effects which take

place among the parts are _essential to our conception of

the whole_; when the whole would not _be_ a whole, nor the

parts, parts, except these effects were produced; when the

effects not only happen in fact, but are included in the

idea of the object; when they are not only seen, but

foreseen; not only expected, but intended: in short when,

instead of being causes and effects, they are _ends_ and

_means_, as they are termed in the above definition.

Thus we necessarily include, in our Idea of Organization,

the notion of an End, a Purpose, a Design; or, to use

another phrase which has been peculiarly appropriated in

this case, a _Final Cause_. This idea of a Final Cause is an

essential condition in order to the pursuing our researches

respecting organized bodies.

4. This Idea of Final Cause is not _deduced_ from the

phenomena by reasoning, but is _assumed_ as the only

condition under which we can reason on such subjects at all.

We do not deduce the Idea of Space, or Time, or efficient

Cause from the phenomena about us, but necessarily look at

phenomena as subordinate to these Ideas from the beginning

of our reasoning. It is true, our ideas of relations of

Space, and Time, and Force, may become much more clear by

our familiarizing ourselves with particular phenomena: but

still, the Fundamental Ideas are not generated, but

unfolded; not extracted from the external world, but evolved

from the world within. In like manner, in the contemplation

of organic structures, we consider {241} each part as

subservient to some use, and we cannot study the structure

as organic without such a conception. This notion of

adaptation,--this Idea of an End,--may become much more

clear and impressive by seeing it exemplified in particular

cases. But still, though suggested and evoked by special

cases, it is not furnished by them. If it be not supplied by

the mind itself, it can never be logically deduced from the

phenomena. It is not a portion of the facts which we study,

but it is a principle which connects, includes, and renders

them intelligible; as our other Fundamental Ideas do the

classes of facts to which they respectively apply.

5. This has already been confirmed by reference to fact; in

the History of Physiology, I have shown that those who

studied the structure of animals were irresistibly led to

the conviction that the parts of this structure have each

its end or purpose;--that each member and organ not merely

produces a certain effect or answers a certain use, but is

so framed as to impress us with the persuasion that it was

constructed _for_ that use:--that it was _intended_ to

produce the effect. It was there seen that this persuasion

was repeatedly expressed in the most emphatic manner by

Galen;--that it directed the researches and led to the

discoveries of Harvey;--that it has always been dwelt upon

as a favourite contemplation, and followed as a certain

guide, by the best anatomists;--and that it is inculcated by

the physiologists of the profoundest views and most

extensive knowledge of our own time. All these persons have

deemed it a most certain and important principle of

physiology, that in every organized structure, plant or

animal, each intelligible part has its allotted

office:--each organ is designed for its appropriate

function:--that nature, in these cases, produces nothing in

vain: that, in short, each portion of the whole arrangement

has its _final cause_; an End to which it is adapted, and in

this End, the reason that it is where and what it is.

6. This Notion of Design in organized bodies must, I say, be

supplied by the student of organization out of his own mind:

a truth which will become clearer if {242} we attend to the

most conspicuous and acknowledged instances of _design_. The

structure of the Eye, in which the parts are curiously

adjusted so as to produce a distinct image on the retina, as

in an optical instrument;--the Trochlear Muscle of the eye,

in which the tendon passes round a support and turns back,

like a rope round a pulley;--the prospective contrivances

for the preservation of animals, provided long before they

are wanted, as the Milk of the mother, the Teeth of the

child, the Eyes and Lungs of the fœtus:--these arrangements,

and innumerable others, call up in us a persuasion that

Design has entered into the plan of animal form and

progress. And if we bring in our minds this conception of

Design, nothing can more fully square with and fit it, than

such instances as these. But if we did not already possess

the Idea of Design;--if we had not had our notion of

mechanical contrivance awakened by inspection of optical

instruments, or pulleys, or in some other way:--if we had

never been conscious ourselves of providing for the

future;--if this were the case, we could not recognize

contrivance and prospectiveness in such instances as we have

referred to. The facts are, indeed, admirably in accordance

with these conceptions, when the two are brought together:

but the facts and the conceptions come together from

different quarters--from without and from within.

7. We may further illustrate this point by referring to the

relations of travellers who tell us that when consummate

examples of human mechanical contrivance have been set

before savages, they have appeared incapable of apprehending

them as proofs of design. This shows that in such cases the

Idea of Design had not been developed in the minds of the

people who were thus unintelligent: but it no more proves

that such an idea does not naturally and necessarily arise,

in the progress of men's minds, than the confused manner in

which the same savages apprehend the relations of space, or

number, or cause, proves that these ideas do not naturally

belong to their intellects. All men have these ideas; and it

is because they {243} cannot help referring their sensations

to such ideas, that they apprehend the world as existing in

time and space, and as a series of causes and effects. It

would be very erroneous to say that the belief of such

truths is obtained by logical reasoning from facts. And in

like manner we cannot logically deduce design from the

contemplation of organic structures; although it is

impossible for us, when the facts are clearly before us, not

to find a reference to design operating in our minds.

8. Again; the evidence of the doctrine of Final Causes as a

fundamental principle of Biology may be obscured and

weakened in some minds by the constant habit of viewing this

doctrine with suspicion as unphilosophical and at variance

with Morphology. By cherishing such views, it is probable

that many persons, physiologists and others, have gradually

brought themselves to suppose that many or most of the

arrangements which are familiarly adduced as instances of

design may be accounted for, or explained away;--that there

is a certain degree of prejudice and narrowness of

comprehension in that lively admiration of the adaptation of

means to ends which common minds derive from the spectacle

of organic arrangements. And yet, even in persons accustomed

to these views, the strong and natural influence of the Idea

of a Final Cause, the spontaneous recognition of the

relation of Means to an End as the assumption which makes

organic arrangements intelligible, breaks forth when we

bring before them a new case, with regard to which their

genuine convictions have not yet been modified by their

intellectual habits. I will offer, as an example which may

serve to illustrate this, the discoveries recently made with

regard to the process of Suckling in the Kangaroo. In the

case of this, as of other pouched animals, the young animal

is removed, while very small and imperfectly formed, from

the womb to the pouch, in which the teats are, and is there

placed with its lips against one of the nipples. But the

young animal taken altogether is not so large as the nipple,

and is therefore incapable of sucking after the manner of

common mammals. Here is a difficulty: {244} how is it

overcome?--By an appropriate _contrivance_: the nipple,

which in common mammals is not furnished with any muscle, is

in the kangaroo provided with a powerful extrusory muscle by

which the mother can inject the milk into the mouth of her

offspring. And again; in order to give attachment to this

muscle there is a bone which is not found in animals of

other kinds. But this mode of solving the problem of

suckling so small a creature introduces another difficulty.

If the milk is injected into the mouth of the young one,

without any action of its own muscles, what is to prevent

the fluid entering the windpipe and producing suffocation?

How is this danger avoided?--By another appropriate

_contrivance_: there is a funnel in the back of the throat

by which the air passage is completely separated from the

passage for nutriment, and the injected milk passes in a

divided stream on each side of the larynx to the

œsophagus[101\9]. And as if to show that this apparatus is

really formed with a view to the wants of the young one, the

structure alters in the course of the animal's growth; and

the funnel, no longer needed, is modified and disappears.

[Note 101\9: Mr. Owen, in _Phil. Trans._ 1834, p. 348.]

With regard to this and similar examples, the remark which I

would urge is this:--that no one, however prejudiced or

unphilosophical he may in general deem the reference to

Final Causes, can, at the first impression, help regarding

this curious system of arrangement as the Means to an End.

So contemplated, it becomes significant, intelligible,

admirable: without such a principle, it is an unmeaning

complexity, a collection of contradictions, producing an

almost impossible result by a portentous conflict of

chances. The parts of this apparatus cannot have produced

one another: one part is in the mother; another part in the

young one: without their harmony they could not be

effective; but nothing except design can operate to make

them harmonious. They are _intended_ to work together; and

we cannot resist the conviction of this intention when the

facts first come before us. Perhaps {245} there may

hereafter be physiologists who, tracing the gradual

development of the parts of which we have spoken, and the

analogies which connect them with the structures of other

animals, may think that this development, these analogies,

account for the conformation we have described; and may

hence think lightly of the explanation derived from the

reference to Final Causes. Yet surely it is clear, on a calm

consideration of the subject, that the latter explanation is

not disturbed by the former; and that the observer's first

impression, that this is 'an irrefragable evidence of

creative foresight[102\9],' can never be obliterated;

however much it may be obscured in the minds of those who

confuse this view by mixing it with others which are utterly

heterogeneous to it, and therefore cannot be contradictory.

[Note 102\9: Mr. Owen, in _Phil. Trans._ 1834, p. 349.]

9. I have elsewhere[103\9] remarked how physiologists, who

thus look with suspicion and dislike upon the introduction

of Final Causes into physiology, have still been unable to

exclude from their speculations causes of this kind. Thus

Cabanis says[104\9], 'I regard with the great Bacon, the

philosophy of Final Causes as sterile; but I have elsewhere

acknowledged that it was very difficult for the most

cautious man never to have recourse to them in his

explanations.' Accordingly, he says, 'The partisans of Final

Causes nowhere find arguments so strong in favour of their

way of looking at nature as in the laws which preside and

the circumstances of all kinds which concur in the

reproduction of living races. In no case do the means

employed appear so clearly relative to the end.' And it

would be easy to find similar acknowledgments, express or

virtual, in other writers of the same kind. Thus Bichat,

after noting the difference between the organic sensibility

by which the organs are made to perform their offices, and

the animal sensibility of which the {246} nervous center is

the seat, says[105\9], 'No doubt it will be asked,

_why_'--that is, as we shall see, for what _end_--'the

organs of internal life have received from nature an

inferior degree of sensibility only, and why they do not

transmit to the brain the impressions which they receive,

while all the acts of the animal life imply this

transmission? The reason is simply this, that all the

phenomena which establish our connexions with surrounding

objects _ought to be_, and are in fact, under the influence

of the Will; while all those which serve for the purpose of

assimilation only, escape, and _ought_ indeed to escape,

such influence.' The _reason_ here assigned is the Final

Cause; which, as Bichat justly says, we cannot help asking

for.

[Note 103\9: _Bridgewater Treatise_, p. 352.]

[Note 104\9: _Rapports du Physique et du Moral_, i. 299.]

[Note 105\9: _Life and Death_, (trans.) p. 32.]

10. Again; I may quote from the writer last mentioned

another remark, which shows that in the organical sciences,

and in them alone, the Idea of forces as Means acting to an

End, is inevitably assumed and acknowledged as of supreme

authority. In Biology alone, observes Bichat[106\9], have we

to contemplate the state of _Disease_. 'Physiology is to the

movements of living bodies, what astronomy, dynamics,

hydraulics, &e., are to those of inert matter: but these

latter sciences have no branches which correspond to them as

Pathology corresponds to Physiology. For the same reason all

notion of a Medicament is repugnant to the physical

sciences. A Medicament has for its object to bring the

properties of the system back to their Natural Type; but the

physical properties never depart from this Type, and have no

need to be brought back to it: and thus there is nothing in

the physical sciences which holds the place of Therapeutick

in Physiology.' Or, as we might express it otherwise, of

inert forces we have no conception of what they _ought to

do_, except what they _do_. The forces of gravity,

elasticity, affinity, never act in a _diseased_ manner; we

never conceive them as failing in their purpose; for we do

not conceive them as having any purpose which is answered by

one mode of their action rather than {247} another. But with

_organical_ forces the case is different; they are

necessarily conceived as acting for the preservation and

development of the system in which they reside. If they do

not do this, they fail, they are deranged, diseased. They

have for their object to conform the living being to a

certain type; and if they cause or allow it to deviate from

this type, their action is distorted, morbid, contrary to

the ends of nature. And thus this conception of organized

beings as susceptible of disease, implies the recognition of

a state of health, and of the organs and the vital forces as

means for preserving this normal condition. The state of

health, and of perpetual development, is necessarily

contemplated as the Final Cause of the processes and powers

with which the different parts of plants and animals are

endowed.

[Note 106\9: _Anatomie Générale_, i. liii.]

11. This Idea of a Final Cause is applicable as a

fundamental and regulative idea to our speculations

concerning organized creatures only. That there is a purpose

in many other parts of the creation, we find abundant reason

to believe, from the arrangements and laws which prevail

around us. But this persuasion is not to be allowed to

regulate and direct our reasonings with regard to inorganic

matter, of which conception the relation of means and end

forms no essential part. In mere Physics, Final Causes, as

Bacon has observed, are not to be admitted as a principle of

reasoning. But in the organical sciences, the assumption of

design and purpose in every part of every whole, that is,

the pervading idea of Final Cause, is the basis of sound

reasoning and the source of true doctrine.

12. The Idea of Final Cause, of end, purpose, design,

intention, is altogether different from the Idea of Cause,

as Efficient Cause, which we formerly had to consider; and

on this account the use of the word Cause in this phrase has

been objected to. If the idea be clearly entertained and

steadily applied, the word is a question of subordinate

importance. The term Final Cause has been long familiarly

used, and appears not likely to lead to confusion. {248}

13. The consideration of Final Causes, both in physiology

and in other subjects, has at all times attracted much

attention, in consequence of its bearing upon the belief of

an Intelligent Author of the Universe. I do not intend, in

this place, to pursue the subject far in this view: but

there is one antithesis of opinion, already noticed in the

History of Physiology, on which I will again make a few

remarks[107\9].

[Note 107\9: _Hist. Ind. Sc._ b. xvii. c. viii. On the

Doctrine of Final Causes in Physiology.]

It has appeared to some persons that the mere aspect of

order and symmetry in the works of nature--the contemplation

of comprehensive and consistent law--is sufficient to lead

us to the conception of a design and intelligence producing

the order and carrying into effect the law. Without here

attempting to decide whether this is true, we may discern,

after what has been said, that the conception of Design,

arrived at in this manner, is altogether different from that

Idea of Design which is suggested to us by organized bodies,

and which we describe as the doctrine of Final Causes. The

regular form of a crystal, whatever beautiful symmetry it

may exhibit, whatever general laws it may exemplify, does

not prove design in the same manner in which design is

proved by the provisions for the preservation and growth of

the seeds of plants, and of the young of animals. The law of

universal gravitation, however wide and simple, does not

impress us with the belief of a purpose, as does that

propensity by which the two sexes of each animal are brought

together. If it could be shown that the symmetrical

structure of a flower results from laws of the same kind as

those which determine the regular forms of crystals, or the

motions of the planets, the discovery might be very striking

and important, but it would not at all come under our idea

of Final Cause.

14. Accordingly, there have been, in modern times, two

different schools of physiologists, the one proceeding upon

the idea of Final Causes, the other school {249} seeking in

the realm of organized bodies wide laws and analogies from

which that idea is excluded. All the great biologists of

preceding times, and some of the greatest of modern times,

have belonged to the former school; and especially Cuvier,

who may be considered as the head of it. It was solely by

the assiduous application of this principle of Final Cause,

as he himself constantly declared, that he was enabled to

make the discoveries which have rendered his name so

illustrious, and which contain a far larger portion of

important anatomical and biological truth than it ever

before fell to the lot of one man to contribute to the science.

The opinions which have been put in opposition to the

principle of Final Causes have, for the most part, been

stated vaguely and ambiguously. Among the most definite of

such principles, is that which, in the History of the

subject, I have termed the Principle of Metamorphosed and

Developed Symmetry, upon which has been founded the science

of Morphology.

The reality and importance of this principle are not to be

denied by us: we have shown how they are proved by its

application in various sciences, and especially in botany.

But those advocates of this principle who have placed it in

antithesis to the doctrine of Final Causes, have, by this

means, done far more injustice to their own favourite

doctrine than damage to the one which they opposed. The

adaptation of the bones of the skeleton to the muscles, the

provision of fulcrums, projecting processes, channels, so

that the motions and forces shall be such as the needs of

life require, cannot possibly become less striking and

convincing, from any discovery of general analogies of one

animal frame with another, or of laws connecting the

development of different parts. Whenever such laws are

discovered, we can only consider them as the means of

producing that adaptation which we so much admire. Our

conviction that the Artist works intelligently, is not

destroyed, though it may be modified and transferred, when

we obtain a sight of his tools. Our discovery of laws cannot

contradict our persuasion of ends; our Morphology cannot

prejudice our Teleology. {250}

15. The irresistible and constant apprehension of a purpose

in the forms and functions of animals has introduced into

the writings of speculators on these subjects various forms

of expression, more or less precise, more or less

figurative; as, that 'animals are framed with a view to the

part which they have to play;'--that 'nature does nothing in

vain;' that 'she employs the best means for her ends;' and

the like. However metaphorical or inexact any of these

phrases may be in particular, yet taken altogether, they

convey, clearly and definitely enough to preclude any

serious errour, a principle of the most profound reality and

of the highest importance in the organical sciences. But

some adherents of the morphological school of which 1 have

spoken reject, and even ridicule, all such modes of

expression. 'I know nothing,' says M. Geoffroy Saint

Hilaire, 'of animals which have to play a part in nature. I

cannot make of nature an intelligent being who does nothing

in vain; who acts by the shortest mode; who does all for the

best.' The philosophers of this school, therefore, do not,

it would seem, feel any of the admiration which is

irresistibly excited in all the rest of mankind at the

contemplation of the various and wonderful adaptations for

the preservation, the enjoyment, the continuation of the

creatures which people the globe;--at the survey of the

mechanical contrivances, the chemical agencies, the

prospective arrangements, the compensations, the minute

adaptations, the comprehensive interdependencies, which

zoology and physiology have brought into view, more and

more, the further their researches have been carried. Yet

the clear and deep-seated conviction of the reality of these

provisions, which the study of anatomy produces in its most

profound and accurate cultivators, cannot be shaken by any

objections to the metaphors or terms in which this

conviction is clothed. In regard to the Idea of a Purpose in

organization, as in regard to any other idea, we cannot

fully express our meaning by phrases borrowed from any

extraneous source; but that impossibility arises precisely

from the circumstance of its being a Fundamental Idea which

is inevitably assumed in our {251} representation of each

special fact. The same objection has been made to the idea

of mechanical _force_, on account of its being often

expressed in metaphorical language; for writers have spoken

of an _energy_, _effort_, or _solicitation_ to motion; and

bodies have been said to be _animated_ by a force. Such

language, it has been urged, implies volition, and the act

of animated beings. But the idea of Force as distinct from

mere motion,--as the Cause of motion, or of tendency to

motion,--is not on that account less real. We endeavour in

vain to conduct our mechanical reasonings without the aid of

this idea, and must express it as we can. Just as little can

we reason concerning organized beings without assuming that

each part has its function, each function its purpose; and

so far as our phrases imply this, they will not mislead us,

however inexact, or however figurative they be.

16. The doctrine of a purpose in Organization has been

sometimes called the doctrine of _the Conditions of

Existence_; and has been stated as teaching that each animal

must be so framed as to contain in its structure the

Conditions which its existence requires. When expressed in

this manner, it has given rise to the objection, that it

merely offers an identical proposition; since no animal can

exist without such conditions. But in reality, such

expressions as those just quoted give an inadequate

statement of the Principle of a Final Cause. For we discover

in innumerable cases, arrangements in an animal, of which we

see, indeed, that they are subservient to its well being;

but the nature of which we never should have been able at

all to conjecture, from considering what was necessary to

its existence, and which strike us, no less by their

unexpectedness than by their adaptation: so far are they

from being presented by any perceptible necessity. Who would

venture to say that the trochlear muscle, or the power of

articulate speech, must occur in man, because they are the

necessary conditions of his existence? When, indeed, the

general scheme and mode of being of an animal are known, the

expert and profound anatomist can reason concerning the

proportions and {252} form of its various parts and organs,

and prove in some measure what their relations must be. We

can assert, with Cuvier, that certain forms of the viscera

require certain forms of the teeth, certain forms of the

limbs, certain powers of the senses. But in all this, the

functions of self-nutrition and digestion are supposed

already existing as ends: and it being taken for granted, as

the only conceivable basis of reasoning, that the organs are

means to these ends, we may discover what modifications of

these organs are necessarily related to and connected with

each other. Instead of terming this rule of speculation

merely 'the Principle of the Conditions of Existence,' we

might term it 'the Principle of the conditions of organs as

_Means_ adapted to animal existence as their _End_.' And how

far this principle is from being a mere barren truism, the

extraordinary discoveries made by the great assertor of the

principle, and universally assented to by naturalists,

abundantly prove. The vast extinct creation which is

recalled to life in Cuvier's great work, the _Ossemens

Fossiles_, cannot be the consequence of a mere identical

proposition.

17. It has been objected, also, that the doctrine of Final

Causes supposes us to be acquainted with the intentions of

the Creator; which, it is insinuated, is a most presumptuous

and irrational basis for our reasonings. But there can be

nothing presumptuous or irrational in reasoning on that

basis, which if we reject, we cannot reason at all. If men

really can discern, and cannot help discerning, a design in

certain portions of the works of creation, this perception

is the soundest and most satisfactory ground for the

convictions to which it leads. The Ideas which we

necessarily employ in the contemplation of the world around

us, afford us the only natural means of forming any

conception of the Creator and Governor of the Universe; and

if we are by such means enabled to elevate our thoughts,

however inadequately, towards Him, where is the presumption

of doing so? or rather, where is the wisdom of refusing to

open our minds to contemplations so animating and elevating,

and yet {253} so entirely convincing? We possess the ideas

of Time and Space, under which all the objects of the

universe present themselves to us; and in virtue of these

ideas thus possessed, we believe the Creator to be eternal

and omnipotent. When we find that we, in like manner,

possess the idea of a Design in Creation, and that with

regard to ourselves, and creatures more or less resembling

ourselves, we cannot but contemplate their constitution

under this idea, we cannot abstain from ascribing to the

Creator the infinite profundity and extent of design to

which all these special instances belong as parts of a whole.

18. I have here considered Design as manifest in

organization only: for in that field of speculation it is

forced upon us as contained in all the phenomena, and as the

only mode of our understanding them. The existence of Final

Causes has often been pointed out in other portions of the

creation;--for instance, in the apparent adaptations of the

various parts of the earth and of the solar system to each

other and to organized beings. In these provinces of

speculation, however, the principle of Final Causes is no

longer the basis and guide, but the sequel and result of our

physical reasonings. If in looking at the universe, we

follow the widest analogies of which we obtain a view, we

see, however dimly, reason to believe that all its laws are

adapted to each other, and intended to work together for the

benefit of its organic population, and for the general

welfare of its rational tenants. On this subject, however,

not immediately included in the principle of Final Causes as

here stated, I shall not dwell. I will only make this

remark; that the assertion appears to be quite unfounded,

that as science advances from point to point, Final Causes

recede before it, and disappear one after the other. The

principle of design changes its mode of application indeed,

but it loses none of its force. We no longer consider

particular facts as produced by special interpositions, but

we consider design as exhibited in the establishment and

adjustment of the laws by which particular facts are

produced. We do not look upon each particular {254} cloud as

brought near us that it may drop fatness on our fields; but

the general adaptation of the laws of heat, and air, and

moisture, to the promotion of vegetation, does not become

doubtful. We do not consider the sun as less intended to

warm and vivify the tribes of plants and animals, because we

find that, instead of revolving round the earth as an

attendant, the earth along with other planets revolves round

him. We are rather, by the discovery of the general laws of

nature, led into a scene of wider design, of deeper

contrivance, of more comprehensive adjustments. Final

causes, if they appear driven further from us by such an

extension of our views, embrace us only with a vaster and

more majestic circuit: instead of a few threads' connecting

some detached objects, they become a stupendous net-work,

which is wound round and round the universal frame of things.

19. I now quit the subject of Biology, and with it the

circle of sciences depending upon separate original Ideas

and permanent relations. If from the general relations which

permanently prevail and constantly recur among the objects

around us, we turn to the inquiry of what has actually

happened,--if from Science we turn to History,--we find

ourselves in a new field. In this region of speculation we

can rarely obtain a complete and scientific view of the

connexion between objects and events. The past History of

Man, of the Arts, of Languages, of the Earth, of the Solar

System, offers a vast series of problems, of which perhaps

not one has been rigorously solved. Still, man, as his

speculative powers unfold themselves, cannot but feel

prompted and invited to employ his thoughts even on these

problems. He cannot but wish and endeavour to understand the

connexion between the successive links of such chains of

events. He attempts to form a Science which shall be

applicable to each of these Histories; and thus he begins to

construct the class of sciences to which I now, in the last

place, proceed.

{{255}}

BOOK X.

THE

PHILOSOPHY

OF

PALÆTIOLOGY.

τὴν μὲν οὖν τοιαύτην _Αἰτιολογίαν_ ἧττον ἄν τις ἀποδέξαιτο·

μᾶλλον _δ᾽ ἀπὸ τῶν φανερωτέρων_ καὶ τῶν καθ᾽ ἡμέραν τρόπον

τινὰ ὁρωμένων ἀναπτέον τὸν λόγον. Καὶ γὰρ κατακλυσμοὶ, καὶ

σεισμοὶ, καὶ ἀναφυσήματα, καὶ ἀνοιδήσεις τῆς ὑφάλου γῆς,

μετεωρίζουσι καὶ τὴν θάλατταν· αἱ δὲ συνιζήσεις ταπεινοῦσιν

αὐτήν.

STRABO, _Geogr._ 1. p. 54.

IT is therefore, not so much what these forms of the earth

actually are, as what they are continually becoming, that we

have to observe; nor is it possible thus to observe them

without an instinctive reference to the first state out of

which they have been brought.... Yet to such questions

continually suggesting themselves, it is never possible to

give a complete answer. For a certain distance, the past

work of existing forces can be traced; but then gradually

the mist gathers, and the footsteps of more gigantic

agencies are traceable in the darkness; and still as we

endeavour to penetrate further and further into departed

time, the thunder of the Almighty power sounds louder and

louder, and the clouds gather broader and more fearfully,

until at last the Sinai of the world is seen altogether upon

a smoke, and the fence of its foot is reached, where none

can break through.

RUSKIN, _Modern Painters_, Vol. IV. p. 143.

{{257}}

BOOK X.

THE PHILOSOPHY OF PALÆTIOLOGY.

CHAPTER I.

OF PALÆTIOLOGICAL SCIENCES IN GENERAL.

1. I HAVE already stated in the _History of the

Sciences_[1\10], that the class of Sciences which I

designate as _Palætiological_ are those in which the object

is to ascend from the present state of things to a more

ancient condition, from which the present is derived by

intelligible causes. As conspicuous examples of this class

we may take Geology, Glossology or Comparative Philology,

and Comparative Archæology. These provinces of knowledge

might perhaps be intelligibly described as _Histories_; the

History of the Earth,--the History of Languages,--the

History of Arts. But these phrases would not fully describe

the sciences we have in view; for the object to which we now

suppose their investigations to be directed is, not merely

to ascertain what the series of events has been, as in the

common forms of History, but also how it has been brought

about. These sciences are to treat of causes as well as of

effects. Such researches might be termed _Philosophical

History_; or, in order to mark more distinctly that the

_causes_ of events are the leading object of attention,

_Ætiological History_. But since {258} it will be more

convenient to describe this class of sciences by a single

appellation, I have taken the liberty of proposing to call

them[2\10] the _Palætiological_ Sciences.

[Note 1\10: B. xviii. Introd.]

[Note 2\10: A philological writer, in a very interesting

work (Mr. Donaldson, in his _New Cratylus_, p. 12),

expresses his dislike of this word, and suggests that I must

mean _palæ-ætiological_. I think the word is more likely to

obtain currency in the more compact and euphonious form in

which I have used it. It has been adopted by Mr. Winning, in

his _Manual of Comparative Philology_, and more recently, by

other writers.]

While Palæontology describes the beings which have lived in

former ages without investigating their causes, and

_Ætiology_ treats of causes without distinguishing

historical from mechanical causation; _Palætiology_ is a

combination of the two sciences; exploring, by means of the

second, the phenomena presented by the first. The portions

of knowledge which I include in this term are

palæontological ætiological sciences.

2. All these sciences are connected by this bond;--that they

all endeavour to ascend to a past state, by considering what

is the present state of things, and what are the causes of

change. Geology examines the existing appearance of the

materials which form the earth, infers from them previous

conditions, and speculates concerning the forces by which

one condition has been made to succeed another. Another

science, cultivated with great zeal and success in modern

times, compares the languages of different countries and

nations, and by an examination of their materials and

structure, endeavours to determine their descent from one

another: this science has been termed _Comparative

Philology_, or _Ethnography_; and by the French,

_Linguistique_, a word which we might imitate in order to

have a single name for the science, but the Greek derivative

_Glossology_ appears to be more convenient in its form. The

progress of the Arts (Architecture and the like);--how one

stage of the culture produced another; and how far we can

trace their maturest and most complete condition to their

earliest form in various nations;--are problems of great

interest belonging to another subject, which we may for the

present term {259} _Comparative Archæology_. I have already

noticed, in the History[3\10] how the researches into the

origin of natural objects, and those relating to works of

art, pass by slight gradations into each other; how the

examination of the changes which have affected an ancient

temple or fortress, harbour or river, may concern alike the

geologist and the antiquary. Cuvier's assertion that the

geologist is an antiquary of a new order, is perfectly

correct, for both are palætiologists.

[Note 3\10: B. xviii. Introd.]

3. We are very far from having exhausted, by this

enumeration, the class of sciences which are thus connected.

We may easily point out many other subjects of speculation

of the same kind. As we may look back towards the first

condition of our planet, we may in like manner turn our

thoughts towards the first condition of the solar system,

and try whether we can discern any traces of an order of

things antecedent to that which is now established; and if

we find, as some great mathematicians have conceived,

indications of an earlier state in which the planets were

not yet gathered into their present forms, we have, in the

pursuit of this train of research, a palætiological portion

of Astronomy. Again, as we may inquire how languages, and

how man, have been diffused over the earth's surface from

place to place, we may make the like inquiry with regard to

the races of plants and animals, founding our inferences

upon the existing geographical distribution of the animal

and vegetable kingdoms: and thus the Geography of Plants and

of Animals also becomes a portion of Palætiology. Again, as

we can in some measure trace the progress of Arts from

nation to nation and from age to age, we can also pursue a

similar investigation with respect to the progress of

Mythology, of Poetry, of Government, of Law. Thus the

philosophical history of the human race, viewed with

reference to these subjects, if it can give rise to

knowledge so exact as to be properly called Science, will

supply Sciences belonging to the class I am now to consider. {260}

4. It is not an arbitrary and useless proceeding to

construct such a Class of Sciences. For wide and various as

their subjects are, it will be found that they have all

certain principles, maxims, and rules of procedure in

common; and thus may reflect light upon each other by being

treated of together. Indeed it will, I trust, appear, that

we may by such a juxtaposition of different speculations,

obtain most salutary lessons. And questions, which, when

viewed as they first present themselves under the aspect of

a special science, disturb and alarm men's minds, may

perhaps be contemplated more calmly, as well as more

clearly, when they are considered as general problems of

palætiology.

5. It will at once occur to the reader that, if we include

in the circuit of our classification such subjects as have

been mentioned,--politics and law, mythology and poetry,--we

are travelling very far beyond the material sciences within

whose limits we at the outset proposed to confine our

discussion of principles. But we shall remain faithful to

our original plan; and for that purpose shall confine

ourselves, in this work, to those palætiological sciences

which deal with material things. It is true, that the

general principles and maxims which regulate these sciences

apply also to investigations of a parallel kind respecting

the products which result from man's imaginative and social

endowments. But although there may be a similarity in the

general form of such portions of knowledge, their materials

are so different from those with which we have been hitherto

dealing, that we cannot hope to take them into our present

account with any profit. Language, Government, Law, Poetry,

Art, embrace a number of peculiar Fundamental Ideas,

hitherto not touched upon in the disquisitions in which we

have been engaged; and most of them involved in far greater

perplexity and ambiguity, the subject of controversies far

more vehement, than the Ideas we have hitherto been

examining. We must therefore avoid resting any part of our

philosophy upon sciences, or supposed sciences, which treat

of such subjects. To attend to this caution, {261} is the

only way in which we can secure the advantage we proposed to

ourselves at the outset, of taking, as the basis of our

speculations, none but systems of undisputed truths, clearly

understood and expressed[4\10]. We have already said that we

must, knowingly and voluntarily, resign that livelier and

warmer interest which doctrines on subjects of Polity or Art

possess, and content ourselves with the cold truths of the

material sciences, in order that we may avoid having the

very foundations of our philosophy involved in controversy,

doubt, and obscurity.

[Note 4\10: See Introd. p. 9.]

6. We may remark, however, that the necessity of rejecting

from our survey a large portion of the researches which the

general notion of Palætiology includes, suggests one

consideration which adds to the interest of our task. We

began our inquiry with the trust that any sound views which

we should be able to obtain respecting the nature of Truth

in the physical sciences, and the mode of discovering it,

must also tend to throw light upon the nature and prospects

of knowledge of all other kinds;--must be useful to us in

moral, political, and philological researches. We stated

this as a confident anticipation; and the evidence of the

justice of our belief already begins to appear. We have

seen, in the last Book, that biology leads us to psychology,

if we choose to follow the path; and thus the passage from

the material to the immaterial has already unfolded itself

at one point; and we now perceive that there are several

large provinces of speculation which concern subjects

belonging to man's immaterial nature, and which are governed

by the same laws as sciences altogether physical. It is not

our business here to dwell on the prospects which our

philosophy thus opens to our contemplation; but we may allow

ourselves, in this last stage of our pilgrimage among the

foundations of the physical sciences, to be cheered and

animated by the ray {262} that thus beams upon us, however

dimly, from a higher and brighter region.

But in our reasonings and examples we shall mainly confine

ourselves to the physical sciences; and for the most part to

Geology, which in the _History_ I have put forwards as the

best representative of the Palætiological Sciences.

{{263}}

CHAPTER II.

OF THE THREE MEMBERS OF A PALÆTIOLOGICAL SCIENCE.

1. _Divisions of such Sciences._--IN each of the Sciences of

this class we consider some particular order of phenomena

now existing:--from our knowledge of the causes of change

among such phenomena, we endeavour to infer the causes which

have made this order of things what it is:--we ascend in

this manner to some previous stage of such phenomena;--and

from that, by a similar course of inference, to a still

earlier stage, and to its causes. Hence it will be seen that

each such science will consist of two parts,--the knowledge

of the Phenomena, and the knowledge of their Causes. And

such a division is, in fact, generally recognized in such

sciences: thus we have History, and the Philosophy of

History; we have Comparison of Languages, and the Theories

of the Origin and Progress of Language; we have Descriptive

Geology, and Theoretical or Physical Geology. In all these

cases, the relation between the two parts in these several

provinces of knowledge is nearly the same; and it may, on

some occasions at least, be useful to express the

distinction in a uniform or general manner. The

investigation of Causes has been termed _Ætiology_ by

philosophical writers, and this term we may use, in

contradistinction to the mere _Phenomenology_ of each such

department of knowledge. And thus we should have _Phenomenal

Geology_ and _Ætiological Geology_, for the two divisions of

the science which we have above termed _Descriptive_ and

_Theoretical Geology_.

2. _The Study of Causes._--But our knowledge respecting the

causes which actually _have_ produced any {264} order of

phenomena must be arrived at by ascertaining what the causes

of change in such matters _can_ do. In order to learn, for

example, what share earthquakes, and volcanoes, and the

beating of the ocean against its shores, ought to have in

our Theory of Geology, we must make out what effects these

agents of change are able to produce. And this must be done,

not hastily, or unsystematically, but in a careful and

connected manner; in short, this study of the causes of

change in each order of phenomena must become a distinct

body of Science, which must include a large amount of

knowledge, both comprehensive and precise, before it can be

applied to the construction of a theory. We must have an

Ætiology corresponding to each order of phenomena.

3. _Ætiology._--In the History of Geology, I have spoken of

the necessity for such an Ætiology with regard to geological

phenomena: this necessity I have compared with that which,

at the time of Kepler, required the formation of a separate

science of Dynamics (the doctrine of the Causes of Motion),

before Physical Astronomy could grow out of Phenomenal

Astronomy. In pursuance of this analogy, I have there given

the name of _Geological Dynamics_ to the science which

treats of the causes of geological change in general. But,

as I have there intimated, in a large portion of the subject

the changes are so utterly different in their nature from

any modification of motion, that the term _Dynamics_, so

applied, sounds harsh and strange. For in this science we

have to treat, not only of the subterraneous forces by which

parts of the earth's crust are shaken, elevated, or

ruptured, but also of the causes which may change the

climate of a portion of the earth's surface, making a

country hotter or colder than in former ages; again, we have

to treat of the causes which modify the forms and habits of

animals and vegetables, and of the extent to which the

effects of such causes can proceed; whether, for instance,

they can extinguish old species and produce new. These and

other similar investigations would not be naturally included

in the notion of _Dynamics_; and therefore it {265} might

perhaps be better to use the term _Ætiology_ when we wish to

group together all those researches which have it for their

object to determine the laws of such changes. In the same

manner the Comparison and History of Languages, if it is to

lead to any stable and exact knowledge, must have appended

to it an Ætiology, which aims at determining the nature and

the amount of the causes which really do produce changes in

language; as colonization, conquest, the mixture of races,

civilization, literature, and the like. And the same rule

applies to all sciences of this class. We shall now make a

few remarks on the characteristics of such branches of

science as those to which we are led by the above

considerations.

4. _Phenomenology requires Classification. Phenomenal

Geology._--The Phenomenal portions of each science imply

Classification, for no description of a large and varied

mass of phenomena can be useful or intelligible without

classification. A representation of phenomena, in order to

answer the purposes of science, must be systematic.

Accordingly, in giving the History of Descriptive or

Phenomenal Geology, I have called it _Systematic Geology_,

just as Classificatory Botany is termed _Systematic Botany_.

Moreover, as we have already seen, Classification can never

be an arbitrary process, but always implies some natural

connexion among the objects of the same Class; for if this

connexion did not exist, the Classes could not be made the

subjects of any true assertion. Yet though the classes of

phenomena which our system acknowledges must be such as

already exist in nature, the discovery of these classes is,

for the most part, very far from obvious or easy. To detect

the true principles of Natural Classes, and to select marks

by which these may be recognized, are steps which require

genius and good fortune, and which fall to the lot only of

the most eminent persons in each science. In the History, I

have pointed out Werner, William Smith, and Cuvier, as the

three great authors of Systematic Geology of Europe. The

mode of classifying the materials of the earth's surface

which was found, by these philosophers, fitted to {266}

enunciate such general facts as came under their notice, was

to consider the rocks and other materials as divided into

successive layers or strata, superimposed one on another,

and variously inclined and broken. The German geologist

distinguished his strata for the most part by their

mineralogical character; the other two, by the remains of

animals and plants which the rocks contained. After a

beginning had thus been made in giving a genuine scientific

form to phenomenal geology, other steps followed in rapid

succession, as has already been related in the

History[5\10]. The Classification of the Strata was fixed by

a suitable Nomenclature. Attempts were made to apply to

other countries the order of strata which had been found to

prevail in that first studied: and in this manner it was

ascertained what rocks in distant regions are the synonyms,

or _Equivalents_[6\10],--of each other. The knowledge thus

collected and systematized was exhibited in the form of

Geological Maps.

[Note 5\10: _Hist. Ind. Sc._ b. xviii. c. iii.]

[Note 6\10: _Ib._ sect. 4.]

Moreover, among the phenomena of geology we have Laws of

Nature as well as Classes. The general form of

mountain-chains; the relations of the direction and

inclination of different chains to each other; the general

features of mineral veins, faults, and fissures; the

prevalent characters of slaty cleavage;--were the subjects

of laws established, or supposed to be established, by

extensive observation of facts. In like manner the organic

fossils discovered in the strata were found to follow

certain laws with reference to the climate which they

appeared to have lived in; and the evidence which they gave

of a regular zoological development. And thus, by the

assiduous labours of many accomplished and active

philosophers, Descriptive or Phenomenal Geology was carried

towards a state of completeness.

5. _Phenomenal Uranography._--In like manner in other

palætiological researches, as soon as they approach to an

exact and scientific form, we find the necessity of

constructing in the first place a science of {267}

classification and exact description, by means of which the

phenomena may be correctly represented and compared; and of

obtaining by this step a solid basis for an inquiry into the

causes which have produced them. Thus the Palætiology of the

Solar System has, in recent times, drawn the attention of

speculators; and a hypothesis has been started, that our sun

and his attendant planets have been produced by the

condensation of a mass of diffused matter, such as that

which constitutes the nebulous patches which we observe in

the starry heavens. But the sagest and most enlightened

astronomers have not failed to acknowledge, that to verify

or to disprove this conjecture, must be the work of many

ages of observation and thought. They have perceived also

that the first step of the labour requisite for the

advancement of this portion of science must be to obtain and

to record the most exact knowledge at present within our

reach, respecting the phenomena of these nebulæ, with which

we thus compare our own system; and, as a necessary element

of such knowledge, they have seen the importance of a

classification of these objects, and of others, such as

Double Stars, of the same kind. Sir William Herschel, who

first perceived the bearing of the phenomena of nebulæ upon

the history of the solar system, made the observation of

such objects his business, with truly admirable zeal and

skill; and in the account of the results of his labours,

gave a classification of Nebulæ; separating them into,

first, _Clusters of Stars_; second, _Resolvable Nebulæ_;

third, _Proper Nebulæ_; fourth, _Planetary Nebulæ_; fifth,

_Stellar Nebulæ_; sixth, _Nebulous Stars_[7\10]. And since,

in order to obtain from these remote appearances, any

probable knowledge respecting our own system, we must

discover whether they undergo any changes in the course of

ages, he devoted himself to the task of forming a record of

their number and appearance in his own time, that thus the

astronomers of succeeding generations might have a {268}

definite and exact standard with which to compare their

observations. Still, this task would have been executed only

for that part of the heavens which is visible in this

country, if this Hipparchus of the Nebulæ and Double Stars

had not left behind him a son who inherited all his father's

zeal and more than his father's knowledge. Sir John Herschel

in 1833 went to the Cape of Good Hope to complete what Sir

William Herschel left wanting; and in the course of five

years observed with care all the nebulæ and double stars of

the Southern hemisphere. This great _Herschelian Survey of

the Heavens_, the completion of which is the noblest

monument ever erected by a son to a father, must necessarily

be, to all ages, the basis of all speculations concerning

the history and origin of the solar system; and has

completed, so far as at present it can be completed, the

phenomenal portion of Astronomical Palætiology.

[Note 7\10: _Phil. Trans._ 1786 and 1789, and Sir J.

Herschel's _Astronomy_, Art. 616.]

6. _Phenomenal Geography of Plants and Animals._--Again,

there is another Palætiological Science, closely connected

with the speculations forced upon the geologist by the

organic fossils which he discovers imbedded in the strata of

the earth;--namely, the Science which has for its object the

Causes of the Diffusion and Distribution of the various

kinds of Plants and Animals. And the science also has for

its first portion and indispensable foundation a description

and classification of the existing phenomena. Such portions

of science have recently been cultivated with great zeal and

success, under the titles of the _Geography of Plants_, and

the _Geography of Animals_. And the results of the inquiries

thus undertaken have assumed a definite and scientific form

by leading to a division of the earth's surface into a

certain number of botanical and zoological _Provinces_, each

province occupied by its own peculiar vegetable and animal

population. We find, too, in the course of these

investigations, various general laws of the phenomena

offered to our notice; such, for instance, as this:--that

the difference of the animals originally occupying each

province, which is clear and entire for the higher orders of

{269} animals and plants, becomes more doubtful and

indistinct when we descend to the lower kinds of

organizations; as Infusoria and Zoophytes[8\10] in the

animal kingdom, Grasses and Mosses among vegetables. Again,

other laws discovered by those who have studied the

geography of plants are these:--that countries separated

from each other by wide tracts of sea, as the opposite

shores of the Mediterranean, the islands of the Indian and

Pacific Oceans, have usually much that is common in their

vegetation:--and again, that in parallel climates, analogous

tribes replace each other. It would be easy to adduce other

laws, but those already stated may serve to show the great

extent of the portions of knowledge which have just been

mentioned, even considered as merely Sciences of Phenomena.

[Note 8\10: Prichard, _Researches into the Physical History

of Mankind_, i. 55, 28.]