The Quarterly Reviewer entrenches himself within formidable-looking

psychological outworks, and there is no getting at him without

attacking them one by one.

He begins by laying down the following proposition: "'Sensation' is

not 'thought,' and no amount of the former would constitute the most

rudimentary condition of the latter, though sensations supply the

conditions for the existence of 'thought' or 'knowledge'" (p. 67).

This proposition is true, or not, according to the sense in which the

word "thought" is employed. Thought is not uncommonly used in a sense

co-extensive with consciousness, and, especially, with those states

of consciousness we call memory. If I recall the impression made by a

colour or an odour, and distinctly remember blueness or muskiness, I

may say with perfect propriety that I "think of" blue or musk; and,

so long as the thought lasts, it is simply a faint reproduction of the

state of consciousness to which I gave the name in question, when it

first became known to me as a sensation.

Now, if that faint reproduction of a sensation, which we call the

memory of it, is properly termed a thought, it seems to me to be

a somewhat forced, proceeding to draw a hard and fast line of

demarcation between thoughts and sensations. If sensations are

not rudimentary thoughts, it may be said that some thoughts are

rudimentary sensations. No amount of sound constitutes an echo, but

for all that no one would pretend that an echo is something of totally

different nature from a sound. Again, nothing can be looser, or more

inaccurate, than the assertion that "sensations supply the conditions

for the existence of thought or knowledge." If this implies that

sensations supply the conditions for the existence of our memory of

sensations or of our thoughts about sensations, it is a truism which

it is hardly worth while to state so solemnly. If it implies that

sensations supply anything else, it is obviously erroneous. And if it

means, as the context would seem to show it does, that sensations are

the subject-matter of all thought or knowledge, then it is no less

contrary to fact, inasmuch as our emotions, which constitute a

large part of the subject-matter of thought or of knowledge, are not

sensations.

More eccentric still is the Quarterly Reviewer's next piece of

psychology.

"Altogether, we may clearly distinguish at least six kinds of

action to which the nervous system ministers:--

"I. That in which impressions received result in appropriate

movements without the intervention of sensation or thought, as

in the cases of injury above given.--This is the reflex action

of the nervous system.

"II. That in which stimuli from without result in sensations

through the agency of which their due effects are wrought

out--Sensation.

"III. That in which impressions received result in

sensations which give rise to the observation of sensible

objects.--Sensible perception.

"IV. That in which sensations and perceptions continue to

coalesce, agglutinate, and combine in more or less complex

aggregations, according to the laws of the association of

sensible perceptions.--Association.

"The above four groups contain only indeliberate operations,

consisting, as they do at the best, but of mere _presentative_

sensible ideas in no way implying any reflective or

_representative_ faculty. Such actions minister to and form

_Instinct_. Besides these, we may distinguish two other kinds

of mental action, namely:--

"V. That in which sensations and sensible perceptions are

reflected on by thought, and recognized as our own, and

we ourselves recognized by ourselves as affected and

perceiving.--Self-consciousness.

"VI. That in which we reflect upon our sensations or

perceptions, and ask what they are, and why they are.--Reason.

"These two latter kinds of action are deliberate operations,

performed, as they are, by means of representative ideas

implying the use of a _reflective representative_ faculty.

Such actions distinguish the _intellect_ or rational faculty.

Now, we assert that possession in perfection of all the first

four _(presentative)_ kinds of action by no means implies

the possession of the last two _(representative)_ kinds.

All persons, we think, must admit the truth of the following

proposition:--

"Two faculties are distinct, not in degree but _in kind_,

if we may possess the one in perfection without that fact

implying that we possess the other also. Still more will

this be the case if the two faculties tend to increase in

an inverse ratio. Yet this is the distinction between the

_instinctive_ and the _intellectual_ parts of man's nature.

"As to animals, we fully admit that they may possess all the

first four groups of actions--that they may have, so to speak,

mental images of sensible objects combined in all degrees of

complexity, as governed by the laws of association. We deny to

them, on the other hand, the possession of the last two

kinds of mental action. We deny them, that is, the power of

reflecting on their own existence, or of inquiring into the

nature of objects and their causes. We deny that they know

that they know or know themselves in knowing. In other words,

we deny them _reason_. The possession of the presentative

faculty, as above explained, in no way implies that of the

reflective faculty; nor does any amount of direct operation

imply the power of asking the reflective question before

mentioned, as to 'what' and 'why.'" _(Loc. cit_. pp. 67, 68.)

Sundry points are worthy of notice in this remarkable account of the

intellectual powers. In the first place the Reviewer ignores emotion

and volition, though they are no inconsiderable "kinds of action to

which the nervous system ministers," and memory has a place in his

classification only by implication. Secondly, we are told that the

second "kind of action to which the nervous system ministers" is "that

in which stimuli from without result in sensations through the agency

of which their due effects are wrought out.--Sensation." Does this

really mean that, in the writer's opinion, "sensation" is the "agent"

by which the "due effect" of the stimulus, which gives rise to

sensation, is "wrought out"? Suppose somebody runs a pin into me. The

"due effect" of that particular stimulus will probably be threefold;

namely, a sensation of pain, a start, and an interjectional expletive.

Does the Quarterly Reviewer really think that the "sensation" is the

"agent" by which the other two phenomena are wrought out?

But these matters are of little moment to anyone but the Reviewer

and those persons who may incautiously take their physiology, or

psychology, from him. The really interesting point is this, that when

he fully admits that animals "may possess all the first four groups

of actions," he grants all that is necessary for the purposes of

the evolutionist. For he hereby admits that in animals "impressions

received result in sensations which give rise to the observation

of sensible objects," and that they have what he calls "sensible

perception." Nor was it possible to help the admission; for we have

as much reason to ascribe to animals, as we have to attribute to our

fellow-men, the power, not only of perceiving external objects as

external, and thus practically recognizing the difference between the

self and the not-self; but that of distinguishing between like

and unlike, and between simultaneous and successive things. When a

gamekeeper goes out coursing with a greyhound in leash, and a hare

crosses the field of vision, he becomes the subject of those states

of consciousness we call visual sensation, and that is all he receives

from without. Sensation, as such, tells him nothing whatever about

the cause of these states of consciousness; but the thinking faculty

instantly goes to work upon the raw material of sensation furnished to

it through the eye, and gives rise to a train of thoughts. First comes

the thought that there is an object at a certain distance; then arises

another thought--the perception of the likeness between the states of

consciousness awakened by this object to those presented by memory,

as, on some former occasion, called up by a hare; this is succeeded

by another thought of the nature of an emotion--namely, the desire

to possess the hare; then follows a longer or shorter train of other

thoughts, which end in a volition and an act--the loosing of the

greyhound from the leash. These several thoughts are the concomitants

of a process which goes on in the nervous system of the man. Unless

the nerve-elements of the retina, of the optic nerve, of the brain, of

the spinal chord, and of the nerves of the arms went through certain

physical changes in due order and correlation, the various states

of consciousness which have been enumerated would not make their

appearance. So that in this, as in all other intellectual operations,

we have to distinguish two sets of successive changes--one in the

physical basis of consciousness, and the other in consciousness

itself; one set which may, and doubtless will, in course of time,

be followed through all their complexities by the anatomist and the

physicist, and one of which only the man himself can have immediate

knowledge.

As it is very necessary to keep up a clear distinction between

these two processes, let the one be called _neurosis_, and the other

_psychosis_. When the gamekeeper was first trained to his work, every

step in the process of neurosis was accompanied by a corresponding

step in that of psychosis, or nearly so. He was conscious of seeing

something, conscious of making sure it was a hare, conscious of

desiring to catch it, and therefore to loose the greyhound at the

right time, conscious of the acts by which he let the dog out of the

leash. But with practice, though the various steps of the neurosis

remain--for otherwise the impression on the retina would not result

in the loosing of the dog--the great majority of the steps of the

psychosis vanish, and the loosing of the dog follows unconsciously, or

as we say, without thinking about it, upon the sight of the hare.

No one will deny that the series of acts which originally intervened

between the sensation and the letting go of the dog were, in the

strictest sense, intellectual and rational operations. Do they cease

to be so when the man ceases to be conscious of them? That depends

upon what is the essence and what the accident of those operations,

which, taken together, constitute ratiocination.

Now ratiocination is resolvable into predication, and predication

consists in marking, in some way, the existence, the co-existence,

the succession, the likeness and unlikeness, of things or their ideas.

Whatever does this, reasons; and if a machine produces the effects of

reason, I see no more ground for denying to it the reasoning power,

because it is unconscious, than I see for refusing to Mr. Babbage's

engine the title of a calculating machine on the same grounds.

Thus it seems to me that a gamekeeper reasons, whether he is conscious

or unconscious, whether his reasoning is carried on by neurosis alone,

or whether it involves more or less psychosis. And if this is true

of the gamekeeper, it is also true of the greyhound. The essential

resemblances in all points of structure and function, so far as they

can be studied, between the nervous system of the man and that of the

dog, leave no reasonable doubt that the processes which go on in the

one are just like those which take place in the other. In the dog,

there can be no doubt that the nervous matter which lies between

the retina and the muscles undergoes a series of changes, precisely

analogous to those which, in the man, give rise to sensation, a train

of thought, and volition.

Whether this neurosis is accompanied by such psychosis as ours, it is

impossible to say; but those who deny that the nervous changes, which,

in the dog, correspond with those which underlie thought in a man, are

accompanied by consciousness, are equally bound to maintain that those

nervous changes in the dog, which correspond with those which underlie

sensation in a man, are also unaccompanied by consciousness. In other

words, if there is no ground for believing that a dog thinks, neither

is there any for believing that he feels.

As is well known, Descartes boldly faced this dilemma, and

maintained that all animals were mere machines and entirely devoid of

consciousness. But he did not deny, nor can anyone deny, that in this

case they are reasoning machines, capable of performing all those

operations which are performed by the nervous system of man when he

reasons. For even supposing that in man, and in man only, psychosis is

superadded to neurosis--the neurosis which is common to both man

and animal gives their reasoning processes a fundamental unity.

But Descartes's position is open to very serious objections, if the

evidence that animals feel is insufficient to prove that they really

do so. What is the value of the evidence which leads one to believe

that one's fellow-man feels? The only evidence in this argument of

analogy, is the similarity of his structure and of his actions to

one's own. And if that is good enough to prove that one's fellow-man

feels, surely it is good enough to prove that an ape feels. For the

differences of structure and function between men and apes are utterly

insufficient to warrant the assumption, that while men have those

states of consciousness we call sensations, apes have nothing of the

kind. Moreover, we have as good evidence that apes are capable of

emotion and volition as we have that men other than ourselves are. But

if apes possess three out of the four kinds of states of consciousness

which we discover in ourselves, what possible reason is there for

denying them the fourth? If they are capable of sensation, emotion,

and volition, why are they to be denied thought (in the sense of

predication)?

No answer has ever been given to these questions. And as the law of

continuity is as much opposed, as is the common sense of mankind, to

the notion that all animals are unconscious machines, it may safely be

assumed that no sufficient answer ever will be given to them.

There is every reason to believe that consciousness is a function

of nervous matter, when, that nervous matter has attained a certain

degree of organization, just as we know the other "actions to which

the nervous system ministers," such as reflex action and the like, to

be. As I have ventured to state my view of the matter elsewhere, "our

thoughts are the expression of molecular changes in that matter of

life which is the source of our other vital phenomena."

Mr. Wallace objects to this statement in the following terms:--

"Not having been able to find any clue in Professor Huxley's

writings to the steps by which he passes from those vital

phenomena, which consist only, in their last analysis, of

movements by particles of matter, to those other phenomena

which we term thought, sensation, or consciousness; but,

knowing that so positive an expression of opinion from him

will have great weight with many persons, I shall endeavour

to show, with as much brevity as is compatible with clearness,

that this theory is not only incapable of proof, but is also,

as it appears to me, inconsistent with accurate conceptions of

molecular physics."

With all respect for Mr. Wallace, it appears to me that his remarks

are entirely beside the question. I really know nothing whatever, and

never hope to know anything, of the steps by which the passage from

molecular movement to states of consciousness is effected; and I

entirely agree with the sense of the passage which he quotes from

Professor Tyndall, apparently imagining that it is in opposition to

the view I hold.

All that I have to say is, that, in my belief, consciousness and

molecular action are capable of being expressed by one another, just

as heat and mechanical action are capable of being expressed in terms

of one another. Whether we shall ever be able to express consciousness

in foot-pounds, or not, is more than I will venture to say; but

that there is evidence of the existence of some correlation between

mechanical motion and consciousness, is as plain as anything can be.

Suppose the poles of an electric battery to be connected by a platinum

wire. A certain intensity of the current gives rise in the mind of a

bystander to that state of consciousness we call a "dull red light"--a

little greater intensity to another which we call a "bright red

light;" increase the intensity, and the light becomes white; and,

finally, it dazzles, and a new state of consciousness arises, which we

term pain. Given the same wire and the same nervous apparatus, and the

amount of electric force required to give rise to these several states

of consciousness will be the same, however often the experiment

is repeated. And as the electric force, the light-waves, and the

nerve-vibrations caused by the impact of the light-waves on the

retina, are all expressions of the molecular changes which are taking

place in the elements of the battery; so consciousness is, in the same

sense, an expression of the molecular changes which take place in that

nervous matter, which is the organ of consciousness.

And, since this, and any number of similar examples that may be

required, prove that one form of consciousness, at any rate, is, in

the strictest sense, the expression of molecular change, it really

is not worth while to pursue the inquiry, whether a fact so easily

established is consistent with any particular system of molecular

physics or not.

Mr. Wallace, in fact, appears to me to have mixed up two very distinct

propositions: the one, the indisputable truth that consciousness is

correlated with molecular changes in the organ of consciousness;

the other, that the nature of that correlation is known, or can be

conceived, which is quite another matter. Mr. Wallace, presumably,

believes in that correlation of phenomena which we call cause and

effect as firmly as I do. But if he has ever been able to form the

faintest notion how a cause gives rise to its effect, all I can say is

that I envy him. Take the simplest case imaginable--suppose a ball in

motion to impinge upon another ball at rest. I know very well, as a

matter of fact, that the ball in motion will communicate some of its

motion to the ball at rest, and that the motion of the two balls after

collision is precisely correlated with the masses of both balls and

the amount of motion of the first. But how does this come about? In

what manner can we conceive that the _vis viva_ of the first ball

passes into the second? I confess I can no more form any conception

of what happens in this case, than I can of what takes place when the

motion of particles of my nervous matter, caused by the impact of a

similar ball, gives rise to the state of consciousness I call pain. In

ultimate analysis everything is incomprehensible, and the whole object

of science is simply to reduce the fundamental incomprehensibilities

to the smallest possible number.

But to return to the Quarterly Reviewer. He admits that animals

have "mental images of sensible objects, combined in all degrees of

complexity, as governed by the laws of association." Presumably, by

this confused and imperfect statement the Reviewer means to admit

more than the words imply. For mental images of sensible objects,

even though "combined in all degrees of complexity," are, and can be,

nothing more than mental images of sensible objects. But judgments,

emotions, and volitions cannot by any possibility be included under

the head of "mental images of sensible objects."

If the greyhound had no better mental endowment than the Reviewer

allows him, he might have the "mental image" of the "sensible

object"--the hare--and that might be combined with the mental images

of other sensible objects, to any degree of complexity, but he would

have no power of judging it to be at a certain distance from him; no

power of perceiving its similarity to his memory of a hare; and no

desire to get at it. Consequently he would stand stock still, and the

noble art of coursing would have no existence. On the other hand,

as that art is largely practised, it follows that greyhounds alone

possess a number of mental powers, the existence of which, in any

animal, is absolutely denied by the Quarterly Reviewer.

Finally, what are the mental powers which he reserves as the especial

prerogative of man? They are two. First, the recognition of "ourselves

by ourselves as affected and perceiving.--Self-consciousness."

Secondly. "The reflection upon our sensations and perceptions, and

asking what they are and why they are.--Reason."

To the faculty defined in the last sentence, the Reviewer, without

assigning the least ground for thus departing from both common usage

and technical propriety, applies the name of reason. But if man is not

to be considered a reasoning being, unless he asks what his sensations

and perceptions are, and why they are, what is a Hottentot, or an

Australian black fellow; or what the "swinked hedger" of an ordinary

agricultural district? Nay, what becomes of an average country squire

or parson? How many of these worthy persons who, as their wont is,

read the _Quarterly Review_, would do other than stand agape, if you

asked them whether they had ever reflected what their sensations and

perceptions are, and why they are?

So that if the Reviewer's new definition of reason be correct, the

majority of men, even among the most civilized nations, are devoid of

that supreme characteristic of manhood. And if it be as absurd as I

believe it to be, then, as reason is certainly not self-consciousness,

and as it, as certainly, is one of the "actions to which the nervous

system ministers," we must, if the Reviewer's classification is to be

adopted, seek it among those four faculties which he allows animals

to possess. And thus, for the second time, he really surrenders, while

seeming to defend, his position.

The Quarterly Reviewer, as we have seen, lectures the evolutionists

upon their want of knowledge of philosophy altogether. Mr. Mivart

is not less pained at Mr. Darwin's ignorance of moral science. It is

grievous to him that Mr. Darwin (and _nous autres_) should not

have grasped the elementary distinction between material and formal

morality; and he lays down as an axiom, of which no tyro ought to be

ignorant, the position that "acts, unaccompanied by mental acts

of conscious will directed towards the fulfilment of duty," are

"absolutely destitute of the most incipient degree of real or formal

goodness."

Now this may be Mr. Mivart's opinion, but it is a proposition which,

really, does not stand on the footing of an undisputed axiom. Mr. Mill

denies it in his work on Utilitarianism. The most influential writer

of a totally opposed school, Mr. Carlyle, is never weary of denying

it, and upholding the merit of that virtue which is unconscious; nay,

it is, to my understanding, extremely hard to reconcile Mr. Mivart's

dictum with that noble summary of the whole duty of man--"Thou shalt

love the Lord thy God with all thy heart, and with all thy soul, and

with all thy strength; and thou shalt love thy neighbour as thyself."

According to Mr. Mivart's definition, the man who loves God and his

neighbour, and, out of sheer love and affection for both, does all he

can to please them, is, nevertheless, destitute of a particle of real

goodness.

Critiques and Addresses · 第 19 / 24 段