Chapter V.

Of The Law Of Universal Causation.

§ 1. The phenomena of nature exist in two distinct relations to one

another; that of simultaneity, and that of succession. Every phenomenon is

related, in a uniform manner, to some phenomena that co-exist with it, and

to some that have preceded and will follow it.

Of the uniformities which exist among synchronous phenomena, the most

important, on every account, are the laws of number; and next to them

those of space, or, in other words, of extension and figure. The laws of

number are common to synchronous and successive phenomena. That two and

two make four, is equally true whether the second two follow the first two

or accompany them. It is as true of days and years as of feet and inches.

The laws of extension and figure (in other words, the theorems of

geometry, from its lowest to its highest branches) are, on the contrary,

laws of simultaneous phenomena only. The various parts of space, and of

the objects which are said to fill space, co-exist; and the unvarying laws

which are the subject of the science of geometry, are an expression of the

mode of their co-existence.

This is a class of laws, or in other words, of uniformities, for the

comprehension and proof of which it is not necessary to suppose any lapse

of time, any variety of facts or events succeeding one another. The

propositions of geometry are independent of the succession of events. All

things which possess extension, or, in other words, which fill space, are

subject to geometrical laws. Possessing extension, they possess figure;

possessing figure, they must possess some figure in particular, and have

all the properties which geometry assigns to that figure. If one body be a

sphere and another a cylinder, of equal height and diameter, the one will

be exactly two-thirds of the other, let the nature and quality of the

material be what it will. Again, each body, and each point of a body, must

occupy some place or position among other bodies; and the position of two

bodies relatively to each other, of whatever nature the bodies be, may be

unerringly inferred from the position of each of them relatively to any

third body.

In the laws of number, then, and in those of space, we recognize in the

most unqualified manner, the rigorous universality of which we are in

quest. Those laws have been in all ages the type of certainty, the

standard of comparison for all inferior degrees of evidence. Their

invariability is so perfect, that it renders us unable even to conceive

any exception to them; and philosophers have been led, though (as I have

endeavored to show) erroneously, to consider their evidence as lying not

in experience, but in the original constitution of the intellect. If,

therefore, from the laws of space and number, we were able to deduce

uniformities of any other description, this would be conclusive evidence

to us that those other uniformities possessed the same rigorous certainty.

But this we can not do. From laws of space and number alone, nothing can

be deduced but laws of space and number.

Of all truths relating to phenomena, the most valuable to us are those

which relate to the order of their succession. On a knowledge of these is

founded every reasonable anticipation of future facts, and whatever power

we possess of influencing those facts to our advantage. Even the laws of

geometry are chiefly of practical importance to us as being a portion of

the premises from which the order of the succession of phenomena may be

inferred. Inasmuch as the motion of bodies, the action of forces, and the

propagation of influences of all sorts, take place in certain lines and

over definite spaces, the properties of those lines and spaces are an

important part of the laws to which those phenomena are themselves

subject. Again, motions, forces, or other influences, and times, are

numerable quantities; and the properties of number are applicable to them

as to all other things. But though the laws of number and space are

important elements in the ascertainment of uniformities of succession,

they can do nothing toward it when taken by themselves. They can only be

made instrumental to that purpose when we combine with them additional

premises, expressive of uniformities of succession already known. By

taking, for instance, as premises these propositions, that bodies acted

upon by an instantaneous force move with uniform velocity in straight

lines; that bodies acted upon by a continuous force move with accelerated

velocity in straight lines; and that bodies acted upon by two forces in

different directions move in the diagonal of a parallelogram, whose sides

represent the direction and quantity of those forces; we may by combining

these truths with propositions relating to the properties of straight

lines and of parallelograms (as that a triangle is half a parallelogram of

the same base and altitude), deduce another important uniformity of

succession, viz., that a body moving round a centre of force describes

areas proportional to the times. But unless there had been laws of

succession in our premises, there could have been no truths of succession

in our conclusions. A similar remark might be extended to every other

class of phenomena really peculiar; and, had it been attended to, would

have prevented many chimerical attempts at demonstrations of the

indemonstrable, and explanations which do not explain.

It is not, therefore, enough for us that the laws of space, which are only

laws of simultaneous phenomenon, and the laws of number, which though true

of successive phenomena do not relate to their succession, possess the

rigorous certainty and universality of which we are in search. We must

endeavor to find some law of succession which has those same attributes,

and is therefore fit to be made the foundation of processes for

discovering, and of a test for verifying, all other uniformities of

succession. This fundamental law must resemble the truths of geometry in

their most remarkable peculiarity, that of never being, in any instance

whatever, defeated or suspended by any change of circumstances.

Now among all those uniformities in the succession of phenomena, which

common observation is sufficient to bring to light, there are very few

which have any, even apparent, pretension to this rigorous

indefeasibility: and of those few, one only has been found capable of

completely sustaining it. In that one, however, we recognize a law which

is universal also in another sense; it is co-extensive with the entire

field of successive phenomena, all instances whatever of succession being

examples of it. This law is the Law of Causation. The truth that every

fact which has a beginning has a cause, is co-extensive with human

experience.

This generalization may appear to some minds not to amount to much, since

after all it asserts only this: “it is a law, that every event depends on

some law:” “it is a law, that there is a law for every thing.” We must

not, however, conclude that the generality of the principle is merely

verbal; it will be found on inspection to be no vague or unmeaning

assertion, but a most important and really fundamental truth.

§ 2. The notion of Cause being the root of the whole theory of Induction,

it is indispensable that this idea should, at the very outset of our

inquiry, be, with the utmost practicable degree of precision, fixed and

determined. If, indeed, it were necessary for the purpose of inductive

logic that the strife should be quelled, which has so long raged among the

different schools of metaphysicians, respecting the origin and analysis of

our idea of causation; the promulgation, or at least the general

reception, of a true theory of induction, might be considered desperate

for a long time to come. But the science of the Investigation of Truth by

means of Evidence, is happily independent of many of the controversies

which perplex the science of the ultimate constitution of the human mind,

and is under no necessity of pushing the analysis of mental phenomenon to

that extreme limit which alone ought to satisfy a metaphysician.

I premise, then, that when in the course of this inquiry I speak of the

cause of any phenomenon, I do not mean a cause which is not itself a

phenomenon; I make no research into the ultimate or ontological cause of

any thing. To adopt a distinction familiar in the writings of the Scotch

metaphysicians, and especially of Reid, the causes with which I concern

myself are not _efficient_, but _physical_ causes. They are causes in that

sense alone, in which one physical fact is said to be the cause of

another. Of the efficient causes of phenomena, or whether any such causes

exist at all, I am not called upon to give an opinion. The notion of

causation is deemed, by the schools of metaphysics most in vogue at the

present moment, to imply a mysterious and most powerful tie, such as can

not, or at least does not, exist between any physical fact and that other

physical fact on which it is invariably consequent, and which is popularly

termed its cause: and thence is deduced the supposed necessity of

ascending higher, into the essences and inherent constitution of things,

to find the true cause, the cause which is not only followed by, but

actually produces, the effect. No such necessity exists for the purposes

of the present inquiry, nor will any such doctrine be found in the

following pages. The only notion of a cause, which the theory of induction

requires, is such a notion as can be gained from experience. The Law of

Causation, the recognition of which is the main pillar of inductive

science, is but the familiar truth, that invariability of succession is

found by observation to obtain between every fact in nature and some other

fact which has preceded it; independently of all considerations respecting

the ultimate mode of production of phenomena, and of every other question

regarding the nature of “Things in themselves.”

Between the phenomena, then, which exist at any instant, and the phenomena

which exist at the succeeding instant, there is an invariable order of

succession; and, as we said in speaking of the general uniformity of the

course of nature, this web is composed of separate fibres; this collective

order is made up of particular sequences, obtaining invariably among the

separate parts. To certain facts, certain facts always do, and, as we

believe, will continue to, succeed. The invariable antecedent is termed

the cause; the invariable consequent, the effect. And the universality of

the law of causation consists in this, that every consequent is connected

in this manner with some particular antecedent, or set of antecedents. Let

the fact be what it may, if it has begun to exist, it was preceded by some

fact or facts, with which it is invariably connected. For every event

there exists some combination of objects or events, some given concurrence

of circumstances, positive and negative, the occurrence of which is always

followed by that phenomenon. We may not have found out what this

concurrence of circumstances may be; but we never doubt that there is such

a one, and that it never occurs without having the phenomenon in question

as its effect or consequence. On the universality of this truth depends

the possibility of reducing the inductive process to rules. The undoubted

assurance we have that there is a law to be found if we only knew how to

find it, will be seen presently to be the source from which the canons of

the Inductive Logic derive their validity.

§ 3. It is seldom, if ever, between a consequent and a single antecedent,

that this invariable sequence subsists. It is usually between a consequent

and the sum of several antecedents; the concurrence of all of them being

requisite to produce, that is, to be certain of being followed by, the

consequent. In such cases it is very common to single out one only of the

antecedents under the denomination of Cause, calling the others merely

Conditions. Thus, if a person eats of a particular dish, and dies in

consequence, that is, would not have died if he had not eaten of it,

people would be apt to say that eating of that dish was the cause of his

death. There needs not, however, be any invariable connection between

eating of the dish and death; but there certainly is, among the

circumstances which took place, some combination or other on which death

is invariably consequent: as, for instance, the act of eating of the dish,

combined with a particular bodily constitution, a particular state of

present health, and perhaps even a certain state of the atmosphere; the

whole of which circumstances perhaps constituted in this particular case

the _conditions_ of the phenomenon, or, in other words, the set of

antecedents which determined it, and but for which it would not have

happened. The real Cause, is the whole of these antecedents; and we have,

philosophically speaking, no right to give the name of cause to one of

them, exclusively of the others. What, in the case we have supposed,

disguises the incorrectness of the expression, is this: that the various

conditions, except the single one of eating the food, were not _events_

(that is, instantaneous changes, or successions of instantaneous changes)

but _states_, possessing more or less of permanency; and might therefore

have preceded the effect by an indefinite length of duration, for want of

the event which was requisite to complete the required concurrence of

conditions: while as soon as that event, eating the food, occurs, no other

cause is waited for, but the effect begins immediately to take place: and

hence the appearance is presented of a more immediate and close connection

between the effect and that one antecedent, than between the effect and

the remaining conditions. But though we may think proper to give the name

of cause to that one condition, the fulfillment of which completes the

tale, and brings about the effect without further delay; this condition

has really no closer relation to the effect than any of the other

conditions has. All the conditions were equally indispensable to the

production of the consequent; and the statement of the cause is

incomplete, unless in some shape or other we introduce them all. A man

takes mercury, goes out-of-doors, and catches cold. We say, perhaps, that

the cause of his taking cold was exposure to the air. It is clear,

however, that his having taken mercury may have been a necessary condition

of his catching cold; and though it might consist with usage to say that

the cause of his attack was exposure to the air, to be accurate we ought

to say that the cause was exposure to the air while under the effect of

mercury.

If we do not, when aiming at accuracy, enumerate all the conditions, it is

only because some of them will in most cases be understood without being

expressed, or because for the purpose in view they may without detriment

be overlooked. For example, when we say, the cause of a man’s death was

that his foot slipped in climbing a ladder, we omit as a thing unnecessary

to be stated the circumstance of his weight, though quite as indispensable

a condition of the effect which took place. When we say that the assent of

the crown to a bill makes it law, we mean that the assent, being never

given until all the other conditions are fulfilled, makes up the sum of

the conditions, though no one now regards it as the principal one. When

the decision of a legislative assembly has been determined by the casting

vote of the chairman, we sometimes say that this one person was the cause

of all the effects which resulted from the enactment. Yet we do not really

suppose that his single vote contributed more to the result than that of

any other person who voted in the affirmative; but, for the purpose we

have in view, which is to insist on his individual responsibility, the

part which any other person had in the transaction is not material.

In all these instances the fact which was dignified with the name of

cause, was the one condition which came last into existence. But it must

not be supposed that in the employment of the term this or any other rule

is always adhered to. Nothing can better show the absence of any

scientific ground for the distinction between the cause of a phenomenon

and its conditions, than the capricious manner in which we select from

among the conditions that which we choose to denominate the cause. However

numerous the conditions may be, there is hardly any of them which may not,

according to the purpose of our immediate discourse, obtain that nominal

pre-eminence. This will be seen by analyzing the conditions of some one

familiar phenomenon. For example, a stone thrown into water falls to the

bottom. What are the conditions of this event? In the first place there

must be a stone, and water, and the stone must be thrown into the water;

but these suppositions forming part of the enunciation of the phenomenon

itself, to include them also among the conditions would be a vicious

tautology; and this class of conditions, therefore, have never received

the name of cause from any but the Aristotelians, by whom they were called

the _material_ cause, _causa materialis_. The next condition is, there

must be an earth: and accordingly it is often said, that the fall of a

stone is caused by the earth; or by a power or property of the earth, or a

force exerted by the earth, all of which are merely roundabout ways of

saying that it is caused by the earth; or, lastly, the earth’s attraction;

which also is only a technical mode of saying that the earth causes the

motion, with the additional particularity that the motion is toward the

earth, which is not a character of the cause, but of the effect. Let us

now pass to another condition. It is not enough that the earth should

exist; the body must be within that distance from it, in which the earth’s

attraction preponderates over that of any other body. Accordingly we may

say, and the expression would be confessedly correct, that the cause of

the stone’s falling is its being _within the sphere_ of the earth’s

attraction. We proceed to a further condition. The stone is immersed in

water: it is therefore a condition of its reaching the ground, that its

specific gravity exceed that of the surrounding fluid, or in other words

that it surpass in weight an equal volume of water. Accordingly any one

would be acknowledged to speak correctly who said, that the cause of the

stone’s going to the bottom is its exceeding in specific gravity the fluid

in which it is immersed.

Thus we see that each and every condition of the phenomenon may be taken

in its turn, and, with equal propriety in common parlance, but with equal

impropriety in scientific discourse, may be spoken of as if it were the

entire cause. And in practice, that particular condition is usually styled

the cause, whose share in the matter is superficially the most

conspicuous, or whose requisiteness to the production of the effect we

happen to be insisting on at the moment. So great is the force of this

last consideration, that it sometimes induces us to give the name of cause

even to one of the negative conditions. We say, for example, The army was

surprised because the sentinel was off his post. But since the sentinel’s

absence was not what created the enemy, or put the soldiers asleep, how

did it cause them to be surprised? All that is really meant is, that the

event would not have happened if he had been at his duty. His being off

his post was no producing cause, but the mere absence of a preventing

cause: it was simply equivalent to his non-existence. From nothing, from a

mere negation, no consequences can proceed. All effects are connected, by

the law of causation, with some set of _positive_ conditions; negative

ones, it is true, being almost always required in addition. In other

words, every fact or phenomenon which has a beginning, invariably arises

when some certain combination of positive facts exists, provided certain

other positive facts do not exist.

There is, no doubt, a tendency (which our first example, that of death

from taking a particular food, sufficiently illustrates) to associate the

idea of causation with the proximate antecedent _event_, rather than with

any of the antecedent _states_, or permanent facts, which may happen also

to be conditions of the phenomenon; the reason being that the event not

only exists, but begins to exist immediately previous; while the other

conditions may have pre-existed for an indefinite time. And this tendency

shows itself very visibly in the different logical fictions which are

resorted to, even by men of science, to avoid the necessity of giving the

name of cause to any thing which had existed for an indeterminate length

of time before the effect. Thus, rather than say that the earth causes the

fall of bodies, they ascribe it to a _force_ exerted by the earth, or an

_attraction_ by the earth, abstractions which they can represent to

themselves as exhausted by each effort, and therefore constituting at each

successive instant a fresh fact, simultaneous with, or only immediately

preceding, the effect. Inasmuch as the coming of the circumstance which

completes the assemblage of conditions, is a change or event, it thence

happens that an event is always the antecedent in closest apparent

proximity to the consequent: and this may account for the illusion which

disposes us to look upon the proximate event as standing more peculiarly

in the position of a cause than any of the antecedent states. But even

this peculiarity, of being in closer proximity to the effect than any

other of its conditions, is, as we have already seen, far from being

necessary to the common notion of a cause; with which notion, on the

contrary, any one of the conditions, either positive or negative, is

found, on occasion, completely to accord.(114)

The cause, then, philosophically speaking, is the sum total of the

conditions, positive and negative taken together; the whole of the

contingencies of every description, which being realized, the consequent

invariably follows. The negative conditions, however, of any phenomenon, a

special enumeration of which would generally be very prolix, may be all

summed up under one head, namely, the absence of preventing or

counteracting causes. The convenience of this mode of expression is mainly

grounded on the fact, that the effects of any cause in counteracting

another cause may in most cases be, with strict scientific exactness,

regarded as a mere extension of its own proper and separate effects. If

gravity retards the upward motion of a projectile, and deflects it into a

parabolic trajectory, it produces, in so doing, the very same kind of

effect, and even (as mathematicians know) the same quantity of effect, as

it does in its ordinary operation of causing the fall of bodies when

simply deprived of their support. If an alkaline solution mixed with an

acid destroys its sourness, and prevents it from reddening vegetable

blues, it is because the specific effect of the alkali is to combine with

the acid, and form a compound with totally different qualities. This

property, which causes of all descriptions possess, of preventing the

effects of other causes by virtue (for the most part) of the same laws

according to which they produce their own,(115) enables us, by

establishing the general axiom that all causes are liable to be

counteracted in their effects by one another, to dispense with the

consideration of negative conditions entirely, and limit the notion of

cause to the assemblage of the positive conditions of the phenomenon: one

negative condition invariably understood, and the same in all instances

(namely, the absence of counteracting causes) being sufficient, along with

the sum of the positive conditions, to make up the whole set of

circumstances on which the phenomenon is dependent.

§ 4. Among the positive conditions, as we have seen that there are some to

which, in common parlance, the term cause is more readily and frequently

awarded, so there are others to which it is, in ordinary circumstances,

refused. In most cases of causation a distinction is commonly drawn

between something which acts, and some other thing which is acted upon;

between an _agent_ and a _patient_. Both of these, it would be universally

allowed, are conditions of the phenomenon; but it would be thought absurd

to call the latter the cause, that title being reserved for the former.

The distinction, however, vanishes on examination, or rather is found to

be only verbal; arising from an incident of mere expression, namely, that

the object said to be acted upon, and which is considered as the scene in

which the effect takes place, is commonly included in the phrase by which

the effect is spoken of, so that if it were also reckoned as part of the

cause, the seeming incongruity would arise of its being supposed to cause

itself. In the instance which we have already had, of falling bodies, the

question was thus put: What is the cause which makes a stone fall? and if

the answer had been “the stone itself,” the expression would have been in

apparent contradiction to the meaning of the word cause. The stone,

therefore, is conceived as the patient, and the earth (or, according to

the common and most unphilosophical practice, an occult quality of the

earth) is represented as the agent or cause. But that there is nothing

fundamental in the distinction may be seen from this, that it is quite

possible to conceive the stone as causing its own fall, provided the

language employed be such as to save the mere verbal incongruity. We might

say that the stone moves toward the earth by the properties of the matter

composing it; and according to this mode of presenting the phenomenon, the

stone itself might without impropriety be called the agent; though, to

save the established doctrine of the inactivity of matter, men usually

prefer here also to ascribe the effect to an occult quality, and say that

the cause is not the stone itself, but the _weight_ or _gravitation_ of

the stone.

Those who have contended for a radical distinction between agent and

patient, have generally conceived the agent as that which causes some

state of, or some change in the state of, another object which is called

the patient. But a little reflection will show that the license we assume

of speaking of phenomena as _states_ of the various objects which take

part in them (an artifice of which so much use has been made by some

philosophers, Brown in particular, for the apparent explanation of

phenomena), is simply a sort of logical fiction, useful sometimes as one

among several modes of expression, but which should never be supposed to

be the enunciation of a scientific truth. Even those attributes of an

object which might seem with greatest propriety to be called states of the

object itself, its sensible qualities, its color, hardness, shape, and the

like, are in reality (as no one has pointed out more clearly than Brown

himself) phenomena of causation, in which the substance is distinctly the

agent, or producing cause, the patient being our own organs, and those of

other sentient beings. What we call states of objects, are always

sequences into which the objects enter, generally as antecedents or

causes; and things are never more active than in the production of those

phenomena in which they are said to be acted upon. Thus, in the example of

a stone falling to the earth, according to the theory of gravitation the

stone is as much an agent as the earth, which not only attracts, but is

itself attracted by, the stone. In the case of a sensation produced in our

organs, the laws of our organization, and even those of our minds, are as

directly operative in determining the effect produced, as the laws of the

outward object. Though we call prussic acid the agent of a person’s death,

the whole of the vital and organic properties of the patient are as

actively instrumental as the poison, in the chain of effects which so

rapidly terminates his sentient existence. In the process of education, we

may call the teacher the agent, and the scholar only the material acted

upon; yet in truth all the facts which pre-existed in the scholar’s mind

exert either co-operating or counteracting agencies in relation to the

teacher’s efforts. It is not light alone which is the agent in vision, but

light coupled with the active properties of the eye and brain, and with

those of the visible object. The distinction between agent and patient is

merely verbal: patients are always agents; in a great proportion, indeed,

of all natural phenomena, they are so to such a degree as to react

forcibly on the causes which acted upon them: and even when this is not

the case, they contribute, in the same manner as any of the other

conditions, to the production of the effect of which they are vulgarly

treated as the mere theatre. All the positive conditions of a phenomenon

are alike agents, alike active; and in any expression of the cause which

professes to be complete, none of them can with reason be excluded, except

such as have already been implied in the words used for describing the

effect; nor by including even these would there be incurred any but a

merely verbal impropriety.

§ 5. There is a case of causation which calls for separate notice, as it

possesses a peculiar feature, and presents a greater degree of complexity

than the common case. It often happens that the effect, or one of the

effects, of a cause, is, not to produce of itself a certain phenomenon,

but to fit something else for producing it. In other words, there is a

case of causation in which the effect is to invest an object with a

certain property. When sulphur, charcoal, and nitre are put together in

certain proportions and in a certain manner, the effect is, not an

explosion, but that the mixture acquires a property by which, in given

circumstances, it will explode. The various causes, natural and

artificial, which educate the human body or the human mind, have for their

principal effect, not to make the body or mind immediately do any thing,

but to endow it with certain properties—in other words, to give assurance

that in given circumstances certain results will take place in it, or as

consequences of it. Physiological agencies often have for the chief part

of their operation to _predispose_ the constitution to some mode of

action. To take a simpler instance than all these: putting a coat of white

paint upon a wall does not merely produce in those who see it done, the

sensation of white; it confers on the wall the permanent property of

giving that kind of sensation. Regarded in reference to the sensation, the

putting on of the paint is a condition of a condition; it is a condition

of the wall’s causing that particular fact. The wall may have been painted

years ago, but it has acquired a property which has lasted till now, and

will last longer; the antecedent condition necessary to enable the wall to

become in its turn a condition, has been fulfilled once for all. In a case

like this, where the immediate consequent in the sequence is a property

produced in an object, no one now supposes the property to be a

substantive entity “inherent” in the object. What has been produced is

what, in other language, may be called a state of preparation in an object

for producing an effect. The ingredients of the gunpowder have been

brought into a state of preparation for exploding as soon as the other

conditions of an explosion shall have occurred. In the case of the

gunpowder, this state of preparation consists in a certain collocation of

its particles relatively to one another. In the example of the wall, it

consists in a new collocation of two things relatively to each other—the

wall and the paint. In the example of the molding influences on the human

mind, its being a collocation at all is only conjectural; for, even on the

materialistic hypothesis, it would remain to be proved that the increased

facility with which the brain sums up a column of figures when it has been

long trained to calculation, is the result of a permanent new arrangement

of some of its material particles. We must, therefore, content ourselves

with what we know, and must include among the effects of causes, the

capacities given to objects of being causes of other effects. This

capacity is not a real thing existing in the objects; it is but a name for

our conviction that they will act in a particular manner when certain new

circumstances arise. We may invest this assurance of future events with a

fictitious objective existence, by calling it a state of the object. But

unless the state consists, as in the case of the gunpowder it does, in a

collocation of particles, it expresses no present fact; it is but the

contingent future fact brought back under another name.

It may be thought that this form of causation requires us to admit an

exception to the doctrine that the conditions of a phenomenon—the

antecedents required for calling it into existence—must all be found among

the facts immediately, not remotely, preceding its commencement. But what

we have arrived at is not a correction, it is only an explanation, of that

doctrine. In the enumeration of the conditions required for the occurrence

of any phenomenon, it always has to be included that objects must be

present, possessed of given properties. It is a condition of the

phenomenon explosion that an object should be present, of one or other of

certain kinds, which for that reason are called explosive. The presence of

one of these objects is a condition immediately precedent to the

explosion. The condition which is not immediately precedent is the cause

which produced, not the explosion, but the explosive property. The

conditions of the explosion itself were all present immediately before it

took place, and the general law, therefore, remains intact.

§ 6. It now remains to advert to a distinction which is of first-rate

importance both for clearing up the notion of cause, and for obviating a

very specious objection often made against the view which we have taken of

the subject.

When we define the cause of any thing (in the only sense in which the

present inquiry has any concern with causes) to be “the antecedent which

it invariably follows,” we do not use this phrase as exactly synonymous

with “the antecedent which it invariably _has_ followed in our past

experience.” Such a mode of conceiving causation would be liable to the

objection very plausibly urged by Dr. Reid, namely, that according to this

doctrine night must be the cause of day, and day the cause of night; since

these phenomena have invariably succeeded one another from the beginning

of the world. But it is necessary to our using the word cause, that we

should believe not only that the antecedent always _has_ been followed by

the consequent, but that, as long as the present constitution of

things(116) endures, it always _will_ be so. And this would not be true of

day and night. We do not believe that night will be followed by day under

all imaginable circumstances, but only that it will be so _provided_ the

sun rises above the horizon. If the sun ceased to rise, which, for aught

we know, may be perfectly compatible with the general laws of matter,

night would be, or might be, eternal. On the other hand, if the sun is

above the horizon, his light not extinct, and no opaque body between us

and him, we believe firmly that unless a change takes place in the

properties of matter, this combination of antecedents will be followed by

the consequent, day; that if the combination of antecedents could be

indefinitely prolonged, it would be always day; and that if the same

combination had always existed, it would always have been day, quite

independently of night as a previous condition. Therefore is it that we do

not call night the cause, nor even a condition, of day. The existence of

the sun (or some such luminous body), and there being no opaque medium in

a straight line(117) between that body and the part of the earth where we

are situated, are the sole conditions; and the union of these, without the

addition of any superfluous circumstance, constitutes the cause. This is

what writers mean when they say that the notion of cause involves the idea

of necessity. If there be any meaning which confessedly belongs to the

term necessity, it is _unconditionalness_. That which is necessary, that

which _must_ be, means that which will be, whatever supposition we may

make in regard to all other things. The succession of day and night

evidently is not necessary in this sense. It is conditional on the

occurrence of other antecedents. That which will be followed by a given

consequent when, and only when, some third circumstance also exists, is

not the cause, even though no case should ever have occurred in which the

phenomenon took place without it.

Invariable sequence, therefore, is not synonymous with causation, unless

the sequence, besides being invariable, is unconditional. There are

sequences, as uniform in past experience as any others whatever, which yet

we do not regard as cases of causation, but as conjunctions in some sort

accidental. Such, to an accurate thinker, is that of day and night. The

one might have existed for any length of time, and the other not have

followed the sooner for its existence; it follows only if certain other

antecedents exist; and where those antecedents existed, it would follow in

any case. No one, probably, ever called night the cause of day; mankind

must so soon have arrived at the very obvious generalization, that the

state of general illumination which we call day would follow from the

presence of a sufficiently luminous body, whether darkness had preceded or

not.

We may define, therefore, the cause of a phenomenon, to be the antecedent,

or the concurrence of antecedents, on which it is invariably and

_unconditionally_ consequent. Or if we adopt the convenient modification

of the meaning of the word cause, which confines it to the assemblage of

positive conditions without the negative, then instead of

“unconditionally,” we must say, “subject to no other than negative

conditions.”

To some it may appear, that the sequence between night and day being

invariable in our experience, we have as much ground in this case as

experience can give in any case, for recognizing the two phenomena as

cause and effect; and that to say that more is necessary—to require a

belief that the succession is unconditional, or, in other words, that it

would be invariable under all changes of circumstances, is to acknowledge

in causation an element of belief not derived from experience. The answer

to this is, that it is experience itself which teaches us that one

uniformity of sequence is conditional and another unconditional. When we

judge that the succession of night and day is a derivative sequence,

depending on something else, we proceed on grounds of experience. It is

the evidence of experience which convinces us that day could equally exist

without being followed by night, and that night could equally exist

without being followed by day. To say that these beliefs are “not

generated by our mere observation of sequence,”(118) is to forget that

twice in every twenty-four hours, when the sky is clear, we have an

_experimentum crucis_ that the cause of day is the sun. We have an

experimental knowledge of the sun which justifies us on experimental

grounds in concluding, that if the sun were always above the horizon there

would be day, though there had been no night, and that if the sun were

always below the horizon there would be night, though there had been no

day. We thus know from experience that the succession of night and day is

not unconditional. Let me add, that the antecedent which is only

conditionally invariable, is not the invariable antecedent. Though a fact

may, in experience, have always been followed by another fact, yet if the

remainder of our experience teaches us that it might not always be so

followed, or if the experience itself is such as leaves room for a

possibility that the known cases may not correctly represent all possible

cases, the hitherto invariable antecedent is not accounted the cause; but

why? Because we are not sure that it _is_ the invariable antecedent.

Such cases of sequence as that of day and night not only do not contradict

the doctrine which resolves causation into invariable sequence, but are

necessarily implied in that doctrine. It is evident, that from a limited

number of unconditional sequences, there will result a much greater number

of conditional ones. Certain causes being given, that is, certain

antecedents which are unconditionally followed by certain consequents; the

mere co-existence of these causes will give rise to an unlimited number of

additional uniformities. If two causes exist together, the effects of both

will exist together; and if many causes co-exist, these causes (by what we

shall term hereafter the intermixture of their laws) will give rise to new

effects, accompanying or succeeding one another in some particular order,

which order will be invariable while the causes continue to co-exist, but

no longer. The motion of the earth in a given orbit round the sun, is a

series of changes which follow one another as antecedents and consequents,

and will continue to do so while the sun’s attraction, and the force with

which the earth tends to advance in a direct line through space, continue

to co-exist in the same quantities as at present. But vary either of these

causes, and this particular succession of motions would cease to take

place. The series of the earth’s motions, therefore, though a case of

sequence invariable within the limits of human experience, is not a case

of causation. It is not unconditional.

This distinction between the relations of succession which, so far as we

know, are unconditional, and those relations, whether of succession or of

co-existence, which, like the earth’s motions, or the succession of day

and night, depend on the existence or on the co-existence of other

antecedent facts—corresponds to the great division which Dr. Whewell and

other writers have made of the field of science, into the investigation of

what they term the Laws of Phenomena, and the investigation of causes; a

phraseology, as I conceive, not philosophically sustainable, inasmuch as

the ascertainment of causes, such causes as the human faculties can

ascertain, namely, causes which are themselves phenomena, is, therefore,

merely the ascertainment of other and more universal Laws of Phenomena.

And let me here observe, that Dr. Whewell, and in some degree even Sir

John Herschel, seem to have misunderstood the meaning of those writers

who, like M. Comté, limit the sphere of scientific investigation to Laws

of Phenomena, and speak of the inquiry into causes as vain and futile. The

causes which M. Comté designates as inaccessible, are efficient causes.

The investigation of physical, as opposed to efficient, causes (including

the study of all the active forces in Nature, considered as facts of

observation) is as important a part of M. Comté’s conception of science as

of Dr. Whewell’s. His objection to the _word_ cause is a mere matter of

nomenclature, in which, as a matter of nomenclature, I consider him to be

entirely wrong. “Those,” it is justly remarked by Mr. Bailey,(119) “who,

like M. Comté, object to designate _events_ as causes, are objecting

without any real ground to a mere but extremely convenient generalization,

to a very useful common name, the employment of which involves, or needs

involve, no particular theory.” To which it may be added, that by

rejecting this form of expression, M. Comté leaves himself without any

term for marking a distinction which, however incorrectly expressed, is

not only real, but is one of the fundamental distinctions in science;

indeed it is on this alone, as we shall hereafter find, that the

possibility rests of framing a rigorous Canon of Induction. And as things

left without a name are apt to be forgotten, a Canon of that description

is not one of the many benefits which the philosophy of Induction has

received from M. Comté’s great powers.

§ 7. Does a cause always stand with its effect in the relation of

antecedent and consequent? Do we not often say of two simultaneous facts

that they are cause and effect—as when we say that fire is the cause of

warmth, the sun and moisture the cause of vegetation, and the like? Since

a cause does not necessarily perish because its effect has been produced,

the two things do very generally co-exist; and there are some appearances,

and some common expressions, seeming to imply not only that causes may,

but that they must, be contemporaneous with their effects. _Cessante causâ

cessat et effectus_, has been a dogma of the schools: the necessity for

the continued existence of the cause in order to the continuance of the

effect, seems to have been once a generally received doctrine. Kepler’s

numerous attempts to account for the motions of the heavenly bodies on

mechanical principles, were rendered abortive by his always supposing that

the agency which set those bodies in motion must continue to operate in

order to keep up the motion which it at first produced. Yet there were at

all times many familiar instances of the continuance of effects, long

after their causes had ceased. A _coup de soleil_ gives a person

brain-fever: will the fever go off as soon as he is moved out of the

sunshine? A sword is run through his body: must the sword remain in his

body in order that he may continue dead? A plowshare once made, remains a

plowshare, without any continuance of heating and hammering, and even

after the man who heated and hammered it has been gathered to his fathers.

On the other hand, the pressure which forces up the mercury in an

exhausted tube must be continued in order to sustain it in the tube. This

(it may be replied) is because another force is acting without

intermission, the force of gravity, which would restore it to its level,

unless counterpoised by a force equally constant. But again: a tight

bandage causes pain, which pain will sometimes go off as soon as the

bandage is removed. The illumination which the sun diffuses over the earth

ceases when the sun goes down.

There is, therefore, a distinction to be drawn. The conditions which are

necessary for the first production of a phenomenon, are occasionally also

necessary for its continuance; though more commonly its continuance

requires no condition except negative ones. Most things, once produced,

continue as they are, until something changes or destroys them; but some

require the permanent presence of the agencies which produced them at

first. These may, if we please, be considered as instantaneous phenomena,

requiring to be renewed at each instant by the cause by which they were at

first generated. Accordingly, the illumination of any given point of space

has always been looked upon as an instantaneous fact, which perishes and

is perpetually renewed as long as the necessary conditions subsist. If we

adopt this language we avoid the necessity of admitting that the

continuance of the cause is ever required to maintain the effect. We may

say, it is not required to maintain, but to reproduce, the effect, or else

to counteract some force tending to destroy it. And this may be a

convenient phraseology. But it is only a phraseology. The fact remains,

that in some cases (though those are a minority) the continuance of the

conditions which produced an effect is necessary to the continuance of the

effect.

As to the ulterior question, whether it is strictly necessary that the

cause, or assemblage of conditions, should precede, by ever so short an

instant, the production of the effect (a question raised and argued with

much ingenuity by Sir John Herschel in an Essay already quoted),(120) the

inquiry is of no consequence for our present purpose. There certainly are

cases in which the effect follows without any interval perceptible by our

faculties; and when there is an interval, we can not tell by how many

intermediate links imperceptible to us that interval may really be filled

up. But even granting that an effect may commence simultaneously with its

cause, the view I have taken of causation is in no way practically

affected. Whether the cause and its effect be necessarily successive or

not, the beginning of a phenomenon is what implies a cause, and causation

is the law of the succession of phenomena. If these axioms be granted, we

can afford, though I see no necessity for doing so, to drop the words

antecedent and consequent as applied to cause and effect. I have no

objection to define a cause, the assemblage of phenomena, which occurring,

some other phenomenon invariably commences, or has its origin. Whether the

effect coincides in point of time with, or immediately follows, the

hindmost of its conditions, is immaterial. At all events, it does not

precede it; and when we are in doubt, between two co-existent phenomena,

which is cause and which effect, we rightly deem the question solved if we

can ascertain which of them preceded the other.

§ 8. It continually happens that several different phenomena, which are

not in the slightest degree dependent or conditional on one another, are

found all to depend, as the phrase is, on one and the same agent; in other

words, one and the same phenomenon is seen to be followed by several sorts

of effects quite heterogeneous, but which go on simultaneously one with

another; provided, of course, that all other conditions requisite for each

of them also exist. Thus, the sun produces the celestial motions; it

produces daylight, and it produces heat. The earth causes the fall of

heavy bodies, and it also, in its capacity of a great magnet, causes the

phenomena of the magnetic needle. A crystal of galena causes the

sensations of hardness, of weight, of cubical form, of gray color, and

many others between which we can trace no interdependence. The purpose to

which the phraseology of Properties and Powers is specially adapted, is

the expression of this sort of cases. When the same phenomenon is followed

(either subject or not to the presence of other conditions) by effects of

different and dissimilar orders, it is usual to say that each different

sort of effect is produced by a different property of the cause. Thus we

distinguish the attractive or gravitative property of the earth, and its

magnetic property: the gravitative, luminiferous, and calorific properties

of the sun: the color, shape, weight, and hardness of a crystal. These are

mere phrases, which explain nothing, and add nothing to our knowledge of

the subject; but, considered as abstract names denoting the connection

between the different effects produced and the object which produces them,

they are a very powerful instrument of abridgment, and of that

acceleration of the process of thought which abridgment accomplishes.

This class of considerations leads to a conception which we shall find to

be of great importance, that of a Permanent Cause, or original natural

agent. There exist in nature a number of permanent causes, which have

subsisted ever since the human race has been in existence, and for an

indefinite and probably an enormous length of time previous. The sun, the

earth, and planets, with their various constituents, air, water, and other

distinguishable substances, whether simple or compound, of which nature is

made up, are such Permanent Causes. These have existed, and the effects or

consequences which they were fitted to produce have taken place (as often

as the other conditions of the production met), from the very beginning of

our experience. But we can give no account of the origin of the Permanent

Causes themselves. Why these particular natural agents existed originally

and no others, or why they are commingled in such and such proportions,

and distributed in such and such a manner throughout space, is a question

we can not answer. More than this: we can discover nothing regular in the

distribution itself; we can reduce it to no uniformity, to no law. There

are no means by which, from the distribution of these causes or agents in

one part of space, we could conjecture whether a similar distribution

prevails in another. The co-existence, therefore, of Primeval Causes

ranks, to us, among merely casual concurrences: and all those sequences or

co-existences among the effects of several such causes, which, though

invariable while those causes co-exist, would, if the co-existence

terminated, terminate along with it, we do not class as cases of

causation, or laws of nature: we can only calculate on finding these

sequences or co-existences where we know by direct evidence, that the

natural agents on the properties of which they ultimately depend, are

distributed in the requisite manner. These Permanent Causes are not always

objects; they are sometimes events, that is to say, periodical cycles of

events, that being the only mode in which events can possess the property

of permanence. Not only, for instance, is the earth itself a permanent

cause, or primitive natural agent, but the earth’s rotation is so too: it

is a cause which has produced, from the earliest period (by the aid of

other necessary conditions), the succession of day and night, the ebb and

flow of the sea, and many other effects, while, as we can assign no cause

(except conjecturally) for the rotation itself, it is entitled to be

ranked as a primeval cause. It is, however, only the _origin_ of the

rotation which is mysterious to us: once begun, its continuance is

accounted for by the first law of motion (that of the permanence of

rectilinear motion once impressed) combined with the gravitation of the

parts of the earth toward one another.

All phenomena without exception which begin to exist, that is, all except

the primeval causes, are effects either immediate or remote of those

primitive facts, or of some combination of them. There is no Thing

produced, no event happening, in the known universe, which is not

connected by a uniformity, or invariable sequence, with some one or more

of the phenomena which preceded it; insomuch that it will happen again as

often as those phenomena occur again, and as no other phenomenon having

the character of a counteracting cause shall co-exist. These antecedent

phenomena, again, were connected in a similar manner with some that

preceded them; and so on, until we reach, as the ultimate step attainable

by us, either the properties of some one primeval cause, or the

conjunction of several. The whole of the phenomena of nature were

therefore the necessary, or, in other words, the unconditional,

consequences of some former collocation of the Permanent Causes.

The state of the whole universe at any instant, we believe to be the

consequence of its state at the previous instant; insomuch that one who

knew all the agents which exist at the present moment, their collocation

in space, and all their properties, in other words, the laws of their

agency, could predict the whole subsequent history of the universe, at

least unless some new volition of a power capable of controlling the

universe should supervene.(121) And if any particular state of the entire

universe could ever recur a second time, all subsequent states would

return too, and history would, like a circulating decimal of many figures,

periodically repeat itself:

Jam redit et virgo, redeunt Saturnia regna....

Alter erit tum Tiphys, et altera quæ vehat Argo

Delectos heroas; erunt quoque altera bella,

Atque iterum ad Trojam magnus mittetur Achilles.

And though things do not really revolve in this eternal round, the whole

series of events in the history of the universe, past and future, is not

the less capable, in its own nature, of being constructed _a priori_ by

any one whom we can suppose acquainted with the original distribution of

all natural agents, and with the whole of their properties, that is, the

laws of succession existing between them and their effects: saving the far

more than human powers of combination and calculation which would be

required, even in one possessing the data, for the actual performance of

the task.

§ 9. Since every thing which occurs is determined by laws of causation and

collocations of the original causes, it follows that the co-existences

which are observable among effects can not be themselves the subject of

any similar set of laws, distinct from laws of causation. Uniformities

there are, as well of co-existence as of succession, among effects; but

these must in all cases be a mere result either of the identity or of the

co-existence of their causes: if the causes did not co-exist, neither

could the effects. And these causes being also effects of prior causes,

and these of others, until we reach the primeval causes, it follows that

(except in the case of effects which can be traced immediately or remotely

to one and the same cause) the co-existences of phenomena can in no case

be universal, unless the co-existences of the primeval causes to which the

effects are ultimately traceable can be reduced to a universal law: but we

have seen that they can not. There are, accordingly, no original and

independent, in other words no unconditional, uniformities of

co-existence, between effects of different causes; if they co-exist, it is

only because the causes have casually co-existed. The only independent and

unconditional co-existences which are sufficiently invariable to have any

claim to the character of laws, are between different and mutually

independent effects of the same cause; in other words, between different

properties of the same natural agent. This portion of the Laws of Nature

will be treated of in the latter part of the present Book, under the name

of the Specific Properties of Kinds.

§ 10. Since the first publication of the present treatise, the sciences of

physical nature have made a great advance in generalization, through the

doctrine known as the Conservation or Persistence of Force. This imposing

edifice of theory, the building and laying out of which has for some time

been the principal occupation of the most systematic minds among physical

inquirers, consists of two stages: one, of ascertained fact, the other

containing a large element of hypothesis.

To begin with the first. It is proved by numerous facts, both natural and

of artificial production, that agencies which had been regarded as

distinct and independent sources of force—heat, electricity, chemical

action, nervous and muscular action, momentum of moving bodies—are

interchangeable, in definite and fixed quantities, with one another. It

had long been known that these dissimilar phenomena had the power, under

certain conditions, of producing one another: what is new in the theory is

a more accurate estimation of what this production consists in. What

happens is, that the whole or part of the one kind of phenomena

disappears, and is replaced by phenomena of one of the other descriptions,

and that there is an equivalence in quantity between the phenomena that

have disappeared and those which have been produced, insomuch that if the

process be reversed, the very same quantity which had disappeared will

re-appear, without increase or diminution. Thus the amount of heat which

will raise the temperature of a pound of water one degree of the

thermometer, will, if expended, say in the expansion of steam, lift a

weight of 772 pounds one foot, or a weight of one pound 772 feet: and the

same exact quantity of heat can, by certain means, be recovered, through

the expenditure of exactly that amount of mechanical motion.

The establishment of this comprehensive law has led to a change in the

language in which the scientific world had been accustomed to speak of

what are called the Forces of nature. Before this correlation between

phenomena most unlike one another had been ascertained, their unlikeness

had caused them to be referred to so many distinct forces. Now that they

are known to be convertible into one another without loss, they are spoken

of as all of them results of one and the same force, manifesting itself in

different modes. This force (it is said) can only produce a limited and

definite quantity of effect, but always does produce that definite

quantity; and produces it, according to circumstances, in one or another

of the forms, or divides it among several, but so as (according to a scale

of numerical equivalents established by experiment) always to make up the

same sum; and no one of the manifestations can be produced, save by the

disappearance of the equivalent quantity of another, which in its turn, in

appropriate circumstances, will re-appear undiminished. This mutual

interchangeability of the forces of nature, according to fixed numerical

equivalents, is the part of the new doctrine which rests on irrefragable

fact.

To make the statement true, however, it is necessary to add, that an

indefinite and perhaps immense interval of time may elapse between the

disappearance of the force in one form and its re-appearance in another. A

stone thrown up into the air with a given force, and falling back

immediately, will, by the time it reaches the earth, recover the exact

amount of mechanical momentum which was expended in throwing it up,

deduction being made of a small portion of motion which has been

communicated to the air. But if the stone has lodged on a height, it may

not fall back for years, or perhaps ages, and until it does, the force

expended in raising it is temporarily lost, being represented only by

what, in the language of the new theory, is called potential energy. The

coal imbedded in the earth is considered by the theory as a vast reservoir

of force, which has remained dormant for many geological periods, and will

so remain until, by being burned, it gives out the stored-up force in the

form of heat. Yet it is not supposed that this force is a material thing

which can be confined by bounds, as used to be thought of latent heat when

that important phenomenon was first discovered. What is meant is that when

the coal does at last, by combustion, generate a quantity of heat

(transformable like all other heat into mechanical momentum, and the other

forms of force), this extrication of heat is the re-appearance of a force

derived from the sun’s rays, expended myriads of ages ago in the

vegetation of the organic substances which were the material of the coal.

Let us now pass to the higher stage of the theory of Conservation of

Force; the part which is no longer a generalization of proved fact, but a

combination of fact and hypothesis. Stated in few words, it is as follows:

That the Conservation of Force is really the Conservation of Motion; that

in the various interchanges between the forms of force, it is always

motion that is transformed into motion. To establish this, it is necessary

to assume motions which are hypothetical. The supposition is, that there

are motions which manifest themselves to our senses only as heat,

electricity, etc., being molecular motions; oscillations, invisible to us,

among the minute particles of bodies; and that these molecular motions are

transmutable into molar motions (motions of masses), and molar motions

into molecular. Now there is a real basis of fact for this supposition: we

have positive evidence of the existence of molecular motion in these

manifestations of force. In the case of chemical action, for instance, the

particles separate and form new combinations, often with a great visible

disturbance of the mass. In the case of heat, the evidence is equally

conclusive, since heat expands bodies (that is, causes their particles to

move _from_ one another); and if of sufficient amount, changes their mode

of aggregation from solid to liquid, or from liquid to gaseous. Again, the

mechanical actions which produce heat—friction, and the collision of

bodies—must from the nature of the case produce a shock, that is, an

internal motion of particles, which indeed, we find, is often so violent

as to break them permanently asunder. Such facts are thought to warrant

the inference, that it is not, as was supposed, heat that causes the

motion of particles, but the motion of particles that causes heat; the

original cause of both being the previous motion (whether molar or

molecular—collision of bodies or combustion of fuel) which formed the

heating agency. This inference already contains hypothesis; but at least

the supposed cause, the intestine motion of molecules, is a _vera causa_.

But in order to reduce the Conservation of Force to Conservation of

Motion, it was necessary to attribute to motion the heat propagated,

through apparently empty space, from the sun. This required the

supposition (already made for the explanation of the laws of light) of a

subtle ether pervading space, which, though impalpable to us, must have

the property which constitutes matter, that of resistance, since waves are

propagated through it by an impulse from a given point. The ether must be

supposed (a supposition not required by the theory of light) to penetrate

into the minute interstices of all bodies. The vibratory motion supposed

to be taking place in the heated mass of the sun, is considered as

imparted from that mass to the particles of the surrounding ether, and

through them to the particles of the same ether in the interstices of

terrestrial bodies; and this, too, with a sufficient mechanical force to

throw the particles of those bodies into a state of similar vibration,

producing the expansion of their mass, and the sensation of heat in

sentient creatures. All this is hypothesis, though, of its legitimacy as

hypothesis, I do not mean to express any doubt. It would seem to follow as

a consequence from this theory, that Force may and should be defined,

matter in motion. This definition, however, will not stand, for, as has

already been seen, the matter needs not be in _actual_ motion. It is not

necessary to suppose that the motion afterward manifested, is actually

taking place among the molecules of the coal during its sojourn in the

earth;(122) certainly not in the stone which is at rest on the eminence to

which it has been raised. The true definition of Force must be, not

motion, but Potentiality of Motion; and what the doctrine, if established,

amounts to, is, not that there is at all times the same quantity of actual

motion in the universe; but that the possibilities of motion are limited

to a definite quantity, which can not be added to, but which can not be

exhausted; and that all actual motion which takes place in Nature is a

draft upon this limited stock. It needs not all of it have ever existed as

actual motion. There is a vast amount of potential motion in the universe

in the form of gravitation, which it would be a great abuse of hypothesis

to suppose to have been stored up by the expenditure of an equal amount of

actual motion in some former state of the universe. Nor does the motion

produced by gravity take place, so far as we know, at the expense of any

other motion, either molar or molecular.

It is proper to consider whether the adoption of this theory as a

scientific truth, involving as it does a change in the conception hitherto

entertained of the most general physical agencies, requires any

modification in the view I have taken of Causation as a law of nature. As

it appears to me, none whatever. The manifestations which the theory

regards as modes of motion, are as much distinct and separate phenomena

when referred to a single force, as when attributed to several. Whether

the phenomenon is called a transformation of force or the generation of

one, it has its own set or sets of antecedents, with which it is connected

by invariable and unconditional sequence; and that set, or those sets, of

antecedents are its cause. The relation of the Conservation theory to the

principle of Causation is discussed in much detail, and very

instructively, by Professor Bain, in the second volume of his Logic. The

chief practical conclusion drawn by him, bearing on Causation, is, that we

must distinguish in the assemblage of conditions which constitutes the

Cause of a phenomenon, two elements: one, the presence of a force; the

other, the collocation or position of objects which is required in order

that the force may undergo the particular transmutation which constitutes

the phenomenon. Now, it might always have been said with acknowledged

correctness, that a force and a collocation were both of them necessary to

produce any phenomenon. The law of causation is, that change can only be

produced by change. Along with any number of stationary antecedents, which

are collocations, there must be at least one changing antecedent, which is

a force. To produce a bonfire, there must not only be fuel, and air, and a

spark, which are collocations, but chemical action between the air and the

materials, which is a force. To grind corn, there must be a certain

collocation of the parts composing a mill, relatively to one another and

to the corn; but there must also be the gravitation of water, or the

motion of wind, to supply a force. But as the force in these cases was

regarded as a property of the objects in which it is embodied, it seemed

tautology to say that there must be the collocation _and_ the force. As

the collocation must be a collocation of objects possessing the

force-giving property, the collocation, so understood, included the force.

How, then, shall we have to express these facts, if the theory be finally

substantiated that all Force is reducible to a previous Motion? We shall

have to say, that one of the conditions of every phenomenon is an

antecedent Motion. But it will have to be explained that this needs not be

_actual_ motion. The coal which supplies the force exerted in combustion

is not shown to have been exerting that force in the form of molecular

motion in the pit; it was not even exerting pressure. The stone on the

eminence _is_ exerting a pressure, but only equivalent to its weight, not

to the additional momentum it would acquire by falling. The antecedent,

therefore, is not a force in action; and we can still only call it a

property of the objects, by which they would exert a force on the

occurrence of a fresh collocation. The collocation, therefore, still

includes the force. The force said to be stored up, is simply a particular

property which the object has acquired. The cause we are in search of, is

a collocation of objects possessing that particular property. When,

indeed, we inquire further into the cause from which they derive that

property, the new conception introduced by the Conservation theory comes

in: the property is itself an effect, and its cause, according to the

theory, is a former motion of exactly equivalent amount, which has been

impressed on the particles of the body, perhaps at some very distant

period. But the case is simply one of those we have already considered, in

which the efficacy of a cause consists in its investing an object with a

property. The force said to be laid up, and merely potential, is no more a

really existing thing than any other properties of objects are really

existing things. The expression is a mere artifice of language, convenient

for describing the phenomena: it is unnecessary to suppose that any thing

has been in continuous existence except an abstract potentiality. A force

suspended in its operation, neither manifesting itself by motion nor by

pressure, is not an existing fact, but a name for our conviction that in

appropriate circumstances a fact would take place. We know that a pound

weight, were it to fall from the earth into the sun, would acquire in

falling a momentum equal to millions of pounds; but we do not credit the

pound weight with more of actually existing force than is equal to the

pressure it is now exerting on the earth, and that is exactly a pound. We

might as well say that a force of millions of pounds exists in a pound, as

that the force which will manifest itself when the coal is burned is a

real thing existing in the coal. What is fixed in the coal is only a

certain property: it has become fit to be the antecedent of an effect

called combustion, which partly consists in giving out, under certain

conditions, a given definite quantity of heat.

We thus see that no new general conception of Causation is introduced by

the Conservation theory. The indestructibility of Force no more interferes

with the theory of Causation than the indestructibility of Matter, meaning

by matter the element of resistance in the sensible world. It only enables

us to understand better than before the nature and laws of some of the

sequences.

This better understanding, however, enables us, with Mr. Bain, to admit,

as one of the tests for distinguishing causation from mere concomitance,

the expenditure or transfer of energy. If the effect, or any part of the

effect, to be accounted for, consists in putting matter in motion, then

any of the objects present which has lost motion has contributed to the

effect; and this is the true meaning of the proposition that the cause is

that one of the antecedents which exerts active force.

§ 11. It is proper in this place to advert to a rather ancient doctrine

respecting causation, which has been revived during the last few years in

many quarters, and at present gives more signs of life than any other

theory of causation at variance with that set forth in the preceding

pages.

According to the theory in question, Mind, or to speak move precisely,

Will, is the only cause of phenomena. The type of Causation, as well as

the exclusive source from which we derive the idea, is our own voluntary

agency. Here, and here only (it is said), we have direct evidence of

causation. We know that we can move our bodies. Respecting the phenomena

of inanimate nature, we have no other direct knowledge than that of

antecedence and sequence. But in the case of our voluntary actions, it is

affirmed that we are conscious of power before we have experience of

results. An act of volition, whether followed by an effect or not, is

accompanied by a consciousness of effort, “of force exerted, of power in

action, which is necessarily causal, or causative.” This feeling of energy

or force, inherent in an act of will, is knowledge _a priori_; assurance,

prior to experience, that we have the power of causing effects. Volition,

therefore, it is asserted, is something more than an unconditional

antecedent; it is a cause, in a different sense from that in which

physical phenomena are said to cause one another: it is an Efficient

Cause. From this the transition is easy to the further doctrine, that

Volition is the _sole_ Efficient Cause of all phenomena. “It is

inconceivable that dead force could continue unsupported for a moment

beyond its creation. We can not even conceive of change or phenomena

without the energy of a mind.” “The word _action_” itself, says another

writer of the same school, “has no real significance except when applied

to the doings of an intelligent agent. Let any one conceive, if he can, of

any power, energy, or force inherent in a lump of matter.” Phenomena may

have the semblance of being produced by physical causes, but they are in

reality produced, say these writers, by the immediate agency of mind. All

things which do not proceed from a human (or, I suppose, an animal) will

proceed, they say, directly from divine will. The earth is not moved by

the combination of a centripetal and a projectile force; this is but a

mode of speaking, which serves to facilitate our conceptions. It is moved

by the direct volition of an omnipotent Being, in a path coinciding with

that which we deduce from the hypothesis of these two forces.

As I have so often observed, the general question of the existence of

Efficient Causes does not fall within the limits of our subject; but a

theory which represents them as capable of being subjects of human

knowledge, and which passes off as efficient causes what are only physical

or phenomenal causes, belongs as much to Logic as to metaphysics, and is a

fit subject for discussion here.

To my apprehension, a volition is not an efficient, but simply a physical

cause. Our will causes our bodily actions in the same sense, and in no

other, in which cold causes ice, or a spark causes an explosion of

gunpowder. The volition, a state of our mind, is the antecedent; the

motion of our limbs in conformity to the volition, is the consequent. This

sequence I conceive to be not a subject of direct consciousness, in the

sense intended by the theory. The antecedent, indeed, and the consequent,

are subjects of consciousness. But the connection between them is a

subject of experience. I can not admit that our consciousness of the

volition contains in itself any _a priori_ knowledge that the muscular

motion will follow. If our nerves of motion were paralyzed, or our muscles

stiff and inflexible, and had been so all our lives, I do not see the

slightest ground for supposing that we should ever (unless by information

from other people) have known any thing of volition as a physical power,

or been conscious of any tendency in feelings of our mind to produce

motions of our body, or of other bodies. I will not undertake to say

whether we should in that case have had the physical feeling which I

suppose is meant when these writers speak of “consciousness of effort:” I

see no reason why we should not; since that physical feeling is probably a

state of nervous sensation beginning and ending in the brain, without

involving the motory apparatus: but we certainly should not have

designated it by any term equivalent to effort, since effort implies

consciously aiming at an end, which we should not only in that case have

had no reason to do, but could not even have had the idea of doing. If

conscious at all of this peculiar sensation, we should have been conscious

of it, I conceive, only as a kind of uneasiness, accompanying our feelings

of desire.

It is well argued by Sir William Hamilton against the theory in question,

that it “is refuted by the consideration that between the overt fact of

corporeal movement of which we are cognizant, and the internal act of

mental determination of which we are also cognizant, there intervenes a

numerous series of intermediate agencies of which we have no knowledge;

and, consequently, that we can have no consciousness of any causal

connection between the extreme links of this chain, the volition to move

and the limb moving, as this hypothesis asserts. No one is immediately

conscious, for example, of moving his arm through his volition. Previously

to this ultimate movement, muscles, nerves, a multitude of solid and fluid

parts, must be set in motion by the will, but of this motion we know, from

consciousness, absolutely nothing. A person struck with paralysis is

conscious of no inability in his limb to fulfill the determinations of his

will; and it is only after having willed, and finding that his limbs do

not obey his volition, that he learns by this experience, that the

external movement does not follow the internal act. But as the paralytic

learns after the volition that his limbs do not obey his mind; so it is

only after volition that the man in health learns, that his limbs do obey

the mandates of his will.”(123)

Those against whom I am contending have never produced, and do not pretend

to produce, any positive evidence(124) that the power of our will to move

our bodies would be known to us independently of experience. What they

have to say on the subject is, that the production of physical events by a

will seems to carry its own explanation with it, while the action of

matter upon matter seems to require something else to explain it; and is

even, according to them, “inconceivable” on any other supposition than

that some will intervenes between the apparent cause and its apparent

effect. They thus rest their case on an appeal to the inherent laws of our

conceptive faculty; mistaking, as I apprehend, for the laws of that

faculty its acquired habits, grounded on the spontaneous tendencies of its

uncultured state. The succession between the will to move a limb and the

actual motion is one of the most direct and instantaneous of all sequences

which come under our observation, and is familiar to every moment’s

experience from our earliest infancy; more familiar than any succession of

events exterior to our bodies, and especially more so than any other case

of the apparent origination (as distinguished from the mere communication)

of motion. Now, it is the natural tendency of the mind to be always

attempting to facilitate its conception of unfamiliar facts by

assimilating them to others which are familiar. Accordingly, our voluntary

acts, being the most familiar to us of all cases of causation, are, in the

infancy and early youth of the human race, spontaneously taken as the type

of causation in general, and all phenomena are supposed to be directly

produced by the will of some sentient being. This original Fetichism I

shall not characterize in the words of Hume, or of any follower of Hume,

but in those of a religious metaphysician, Dr. Reid, in order more

effectually to show the unanimity which exists on the subject among all

competent thinkers.

“When we turn our attention to external objects, and begin to exercise our

rational faculties about them, we find that there are some motions and

changes in them which we have power to produce, and that there are many

which must have some other cause. Either the objects must have life and

active power, as we have, or they must be moved or changed by something

that has life and active power, as external objects are moved by us.

“Our first thoughts seem to be, that the objects in which we perceive such

motion have understanding and active power as we have. ‘Savages,’ says the

Abbé Raynal, ‘wherever they see motion which they can not account for,

there they suppose a soul.’ All men may be considered as savages in this

respect, until they are capable of instruction, and of using their

faculties in a more perfect manner than savages do.

“The Abbé Raynal’s observation is sufficiently confirmed, both from fact,

and from the structure of all languages.

“Rude nations do really believe sun, moon, and stars, earth, sea, and air,

fountains, and lakes, to have understanding and active power. To pay

homage to them, and implore their favor, is a kind of idolatry natural to

savages.

“All languages carry in their structure the marks of their being formed

when this belief prevailed. The distinction of verbs and participles into

active and passive, which is found in all languages, must have been

originally intended to distinguish what is really active from what is

merely passive; and in all languages, we find active verbs applied to

those objects, in which, according to the Abbé Raynal’s observation,

savages suppose a soul.

“Thus we say the sun rises and sets, and comes to the meridian, the moon

changes, the sea ebbs and flows, the winds blow. Languages were formed by

men who believed these objects to have life and active power in

themselves. It was therefore proper and natural to express their motions

and changes by active verbs.

“There is no surer way of tracing the sentiments of nations before they

have records, than by the structure of their language, which,

notwithstanding the changes produced in it by time, will always retain

some signatures of the thoughts of those by whom it was invented. When we

find the same sentiments indicated in the structure of all languages,

those sentiments must have been common to the human species when languages

were invented.

“When a few, of superior intellectual abilities, find leisure for

speculation, they begin to philosophize, and soon discover, that many of

those objects which at first they believed to be intelligent and active

are really lifeless and passive. This is a very important discovery. It

elevates the mind, emancipates from many vulgar superstitions, and invites

to further discoveries of the same kind.

“As philosophy advances, life and activity in natural objects retires, and

leaves them dead and inactive. Instead of moving voluntarily, we find them

to be moved necessarily; instead of acting, we find them to be acted upon;

and Nature appears as one great machine, where one wheel is turned by

another, that by a third; and how far this necessary succession may reach,

the philosopher does not know.”(125)

There is, then, a spontaneous tendency of the intellect to account to

itself for all cases of causation by assimilating them to the intentional

acts of voluntary agents like itself. This is the instinctive philosophy

of the human mind in its earliest stage, before it has become familiar

with any other invariable sequences than those between its own volitions

or those of other human beings and their voluntary acts. As the notion of

fixed laws of succession among external phenomena gradually establishes

itself, the propensity to refer all phenomena to voluntary agency slowly

gives way before it. The suggestions, however, of daily life continuing to

be more powerful than those of scientific thought, the original

instinctive philosophy maintains its ground in the mind, underneath the

growths obtained by cultivation, and keeps up a constant resistance to

their throwing their roots deep into the soil. The theory against which I

am contending derives its nourishment from that substratum. Its strength

does not lie in argument, but in its affinity to an obstinate tendency of

the infancy of the human mind.

That this tendency, however, is not the result of an inherent mental law,

is proved by superabundant evidence. The history of science, from its

earliest dawn, shows that mankind have not been unanimous in thinking

either that the action of matter upon matter was not conceivable, or that

the action of mind upon matter was. To some thinkers, and some schools of

thinkers, both in ancient and in modern times, this last has appeared much

more inconceivable than the former. Sequences entirely physical and

material, as soon as they had become sufficiently familiar to the human

mind, came to be thought perfectly natural, and were regarded not only as

needing no explanation themselves, but as being capable of affording it to

others, and even of serving as the ultimate explanation of things in

general.

One of the ablest recent supporters of the Volitional theory has furnished

an explanation, at once historically true and philosophically acute, of

the failure of the Greek philosophers in physical inquiry, in which, as I

conceive, he unconsciously depicts his own state of mind. “Their

stumbling-block was one as to the nature of the evidence they had to

expect for their conviction.... They had not seized the idea that they

must not expect to understand the processes of outward causes, but only

their results; and consequently, the whole physical philosophy of the

Greeks was an attempt to identify mentally the effect with its cause, to

feel after some not only necessary but natural connection, where they

meant by natural that which would _per se_ carry some presumption to their

own mind.... They wanted to see some _reason_ why the physical antecedent

should produce this particular consequent, and their only attempts were in

directions where they could find such reasons.”(126) In other words, they

were not content merely to know that one phenomenon was always followed by

another; they thought that they had not attained the true aim of science,

unless they could perceive something in the nature of the one phenomenon

from which it might have been known or presumed _previous to trial_ that

it would be followed by the other: just what the writer, who has so

clearly pointed out their error, thinks that he perceives in the nature of

the phenomenon Volition. And to complete the statement of the case, he

should have added that these early speculators not only made this their

aim, but were quite satisfied with their success in it; not only sought

for causes which should carry in their mere statement evidence of their

efficiency, but fully believed that they had found such causes. The

reviewer can see plainly that this was an error, because _he_ does not

believe that there exist any relations between material phenomena which

can account for their producing one another; but the very fact of the

persistency of the Greeks in this error, shows that their minds were in a

very different state: they were able to derive from the assimilation of

physical facts to other physical facts, the kind of mental satisfaction

which we connect with the word explanation, and which the reviewer would

have us think can only be found in referring phenomena to a will. When

Thales and Hippo held that moisture was the universal cause, and external

element, of which all other things were but the infinitely various

sensible manifestations; when Anaximenes predicated the same thing of air,

Pythagoras of numbers, and the like, they all thought that they had found

a real explanation; and were content to rest in this explanation as

ultimate. The ordinary sequences of the external universe appeared to

them, no less than to their critic, to be inconceivable without the

supposition of some universal agency to connect the antecedents with the

consequents; but they did not think that Volition, exerted by minds, was

the only agency which fulfilled this requirement. Moisture, or air, or

numbers, carried to their minds a precisely similar impression of making

intelligible what was otherwise inconceivable, and gave the same full

satisfaction to the demands of their conceptive faculty.

It was not the Greeks alone, who “wanted to see some reason why the

physical antecedent should produce this particular consequent,” some

connection “which would _per se_ carry some presumption to their own

mind.” Among modern philosophers, Leibnitz laid it down as a self-evident

principle that all physical causes without exception must contain in their

own nature something which makes it intelligible that they should be able

to produce the effects which they do produce. Far from admitting Volition

as the only kind of cause which carried internal evidence of its own

power, and as the real bond of connection between physical antecedents and

their consequents, he demanded some naturally and _per se_ efficient

physical antecedent as the bond of connection between Volition itself and

its effects. He distinctly refused to admit the will of God as a

sufficient explanation of any thing except miracles; and insisted upon

finding something that would account _better_ for the phenomena of nature

than a mere reference to divine volition.(127)

Again, and conversely, the action of mind upon matter (which, we are now

told, not only needs no explanation itself, but is the explanation of all

other effects), has appeared to some thinkers to be itself the grand

inconceivability. It was to get over this very difficulty that the

Cartesians invented the system of Occasional Causes. They could not

conceive that thoughts in a mind could produce movements in a body, or

that bodily movements could produce thoughts. They could see no necessary

connection, no relation _a priori_, between a motion and a thought. And as

the Cartesians, more than any other school of philosophical speculation

before or since, made their own minds the measure of all things, and

refused, on principle, to believe that Nature had done what they were

unable to see any reason why she must do, they affirmed it to be

impossible that a material and a mental fact could be causes one of

another. They regarded them as mere Occasions on which the real agent,

God, thought fit to exert his power as a Cause. When a man wills to move

his foot, it is not his will that moves it, but God (they said) moves it

on the occasion of his will. God, according to this system, is the only

efficient cause, not _quâ_ mind, or _quâ_ endowed with volition, but _quâ_

omnipotent. This hypothesis was, as I said, originally suggested by the

supposed inconceivability of any real mutual action between Mind and

Matter; but it was afterward extended to the action of Matter upon Matter,

for on a nicer examination they found this inconceivable too, and

therefore, according to their logic, impossible. The _deus ex machinâ_ was

ultimately called in to produce a spark on the occasion of a flint and

steel coming together, or to break an egg on the occasion of its falling

on the ground.

All this, undoubtedly, shows that it is the disposition of mankind in

general, not to be satisfied with knowing that one fact is invariably

antecedent and another consequent, but to look out for something which may

seem to explain their being so. But we also see that this demand may be

completely satisfied by an agency purely physical, provided it be much

more familiar than that which it is invoked to explain. To Thales and

Anaximenes, it appeared inconceivable that the antecedents which we see in

nature should produce the consequents; but perfectly natural that water,

or air, should produce them. The writers whom I oppose declare this

inconceivable, but can conceive that mind, or volition, is _per se_ an

efficient cause: while the Cartesians could not conceive even that, but

peremptorily declared that no mode of production of any fact whatever was

conceivable, except the direct agency of an omnipotent being; thus giving

additional proof of what finds new confirmation in every stage of the

history of science: that both what persons can, and what they can not,

conceive, is very much an affair of accident, and depends altogether on

their experience, and their habits of thought; that by cultivating the

requisite associations of ideas, people may make themselves unable to

conceive any given thing; and may make themselves able to conceive most

things, however inconceivable these may at first appear; and the same

facts in each person’s mental history which determine what is or is not

conceivable to him, determine also which among the various sequences in

nature will appear to him so natural and plausible, as to need no other

proof of their existence; to be evident by their own light, independent

equally of experience and of explanation.

By what rule is any one to decide between one theory of this description

and another? The theorists do not direct us to any external evidence; they

appeal each to his own subjective feelings. One says, the succession C B

appears to me more natural, conceivable, and credible _per se_, than the

succession A B; you are therefore mistaken in thinking that B depends upon

A; I am certain, though I can give no other evidence of it, that C comes

in between A and B, and is the real and only cause of B. The other

answers, the successions C B and A B appear to me equally natural and

conceivable, or the latter more so than the former: A is quite capable of

producing B without any other intervention. A third agrees with the first

in being unable to conceive that A can produce B, but finds the sequence D

B still more natural than C B, or of nearer kin to the subject-matter, and

prefers his D theory to the C theory. It is plain that there is no

universal law operating here, except the law that each person’s

conceptions are governed and limited by his individual experiences and

habits of thought. We are warranted in saying of all three, what each of

them already believes of the other two, namely, that they exalt into an

original law of the human intellect and of outward nature one particular

sequence of phenomena, which appears to them more natural and more

conceivable than other sequences, only because it is more familiar. And

from this judgment I am unable to except the theory, that Volition is an

Efficient Cause.

I am unwilling to leave the subject without adverting to the additional

fallacy contained in the corollary from this theory; in the inference that

because Volition is an efficient cause, therefore it is the only cause,

and the direct agent in producing even what is apparently produced by

something else. Volitions are not known to produce any thing directly

except nervous action, for the will influences even the muscles only

through the nerves. Though it were granted, then, that every phenomenon

has an efficient, and not merely a phenomenal cause, and that volition, in

the case of the peculiar phenomena which are known to be produced by it,

is that efficient cause; are we therefore to say, with these writers, that

since we know of no other efficient cause, and ought not to assume one

without evidence, there _is_ no other, and volition is the direct cause of

all phenomena? A more outrageous stretch of inference could hardly be

made. Because among the infinite variety of the phenomena of nature there

is one, namely, a particular mode of action of certain nerves, which has

for its cause, and as we are now supposing for its efficient cause, a

state of our mind; and because this is the only efficient cause of which

we are conscious, being the only one of which in the nature of the case we

_can_ be conscious, since it is the only one which exists within

ourselves; does this justify us in concluding that all other phenomena

must have the same kind of efficient cause with that one eminently

special, narrow, and peculiarly human or animal, phenomenon? The nearest

parallel to this specimen of generalization is suggested by the recently

revived controversy on the old subject of Plurality of Worlds, in which

the contending parties have been so conspicuously successful in

overthrowing one another. Here also we have experience only of a single

case, that of the world in which we live, but that this is inhabited we

know absolutely, and without possibility of doubt. Now if on this evidence

any one were to infer that every heavenly body without exception, sun,

planet, satellite, comet, fixed star or nebula, is inhabited, and must be

so from the inherent constitution of things, his inference would exactly

resemble that of the writers who conclude that because volition is the

efficient cause of our own bodily motions, it must be the efficient cause

of every thing else in the universe. It is true there are cases in which,

with acknowledged propriety, we generalize from a single instance to a

multitude of instances. But they must be instances which resemble the one

known instance, and not such as have no circumstance in common with it

except that of being instances. I have, for example, no direct evidence

that any creature is alive except myself, yet I attribute, with full

assurance, life and sensation to other human beings and animals. But I do

not conclude that all other things are alive merely because I am. I

ascribe to certain other creatures a life like my own, because they

manifest it by the same sort of indications by which mine is manifested. I

find that their phenomena and mine conform to the same laws, and it is for

this reason that I believe both to arise from a similar cause. Accordingly

I do not extend the conclusion beyond the grounds for it. Earth, fire,

mountains, trees, are remarkable agencies, but their phenomena do not

conform to the same laws as my actions do, and I therefore do not believe

earth or fire, mountains or trees, to possess animal life. But the

supporters of the Volition Theory ask us to infer that volition causes

every thing, for no reason except that it causes one particular thing;

although that one phenomenon, far from being a type of all natural

phenomena, is eminently peculiar; its laws bearing scarcely any

resemblance to those of any other phenomenon, whether of inorganic or of

organic nature.

NOTE SUPPLEMENTARY TO THE PRECEDING CHAPTER.

The author of the Second Burnett Prize Essay (Dr. Tulloch), who

has employed a considerable number of pages in controverting the

doctrines of the preceding chapter, has somewhat surprised me by

denying a fact, which I imagined too well known to require

proof—that there have been philosophers who found in physical

explanations of phenomena the same complete mental satisfaction

which we are told is only given by volitional explanation, and

others who denied the Volitional Theory on the same ground of

inconceivability on which it is defended. The assertion of the

Essayist is countersigned still more positively by an able

reviewer of the Essay:(128) “Two illustrations,” says the

reviewer, “are advanced by Mr. Mill: the case of Thales and

Anaximenes, stated by him to have maintained, the one Moisture and

the other Air to be the origin of all things; and that of

Descartes and Leibnitz, whom he asserts to have found the action

of Mind upon Matter the grand inconceivability. In

counter-statement as to the first of these cases the author

shows—what we believe now hardly admits of doubt—that the Greek

philosophers distinctly recognized as beyond and above their

primal material source, the νοῦς, or Divine Intelligence, as the

efficient and originating Source of all; and as to the second, by

proof that it was the _mode_, not the _fact_, of that action on

matter, which was represented as inconceivable.”

A greater quantity of historical error has seldom been comprised

in a single sentence. With regard to Thales, the assertion that he

considered water as a mere material in the hands of νοῦς rests on

a passage of Cicero _de Naturâ Deorum_; and whoever will refer to

any of the accurate historians of philosophy, will find that they

treat this as a mere fancy of Cicero, resting on no authority,

opposed to all the evidence; and make surmises as to the manner in

which Cicero may have been led into the error. (See Rutter, vol.

i., p. 211, 2d ed.; Brandis, vol. i., pp. 118–9, 1st ed.; Preller,

_Historia Philosophiæ Græco-Romanæ_, p. 10. “Schiefe Ansicht,

durchaus zu verwerfen;” “augenscheinlich folgernd statt zu

berichten;” “quibus vera sententia Thaletis plane detorquetur,”

are the expressions of these writers.) As for Anaximenes, he even

according to Cicero, maintained, not that air was the material out

of which God made the world, but that the air was a god:

“Anaximenes aëra deum statuit;” or, according to St. Augustine,

that it was the material out of which the gods were made; “non

tamen ab ipsis [Diis] aërem factum, sed ipsos ex aëre ortos

credidit.” Those who are not familiar with the metaphysical

terminology of antiquity, must not be misled by finding it stated

that Anaximenes attributed ψυχὴ (translated _soul_, or _life_) to

his universal element, the air. The Greek philosophers

acknowledged several kinds of ψυχὴ, the nutritive, the sensitive,

and the intellective.(129) Even the moderns, with admitted

correctness, attribute life to plants. As far as we can make out

the meaning of Anaximenes, he made choice of Air as the universal

agent, on the ground that it is perpetually in motion, without any

apparent cause external to itself: so that he conceived it as

exercising spontaneous force, and as the principle of life and

activity in all things, men and gods inclusive. If this be not

representing it as the Efficient Cause the dispute altogether has

no meaning.

If either Anaximenes, or Thales, or any of their contemporaries,

had held the doctrine that νοῦς was the Efficient Cause, that

doctrine could not have been reputed, as it was throughout

antiquity, to have originated with Anaxagoras. The testimony of

Aristotle, in the first book of his Metaphysics, is perfectly

decisive with respect to these early speculations. After

enumerating four kinds of causes, or rather four different

meanings of the word Cause, viz., the Essence of a thing, the

Matter of it, the Origin of Motion (Efficient Cause), and the End

or Final Cause, he proceeds to say, that most of the early

philosophers recognized only the second kind of Cause, the Matter

of a thing, τὰς ἐν ὕλης εἶδει μόνας ᾠήθησαν ἀρχὰς εἷναι πάντων. As

his first example he specifies Thales, whom he describes as taking

the lead in this view of the subject, ὁ τῆς τοιαύτης ἀρχηγὸς

φιλοσοφίας, and goes on to Hippon, Anaximenes, Diogenes (of

Apollonia), Hippasus of Metapontum, Heraclitus, and Empedocles.

Anaxagoras, however (he proceeds to say), taught a different

doctrine, as we _know_, and it is _alleged_ that Hermotimus of

Clazomenæ taught it before him. Anaxagoras represented, that even

if these various theories of the universal material were true,

there would be need of some other cause to account for the

transformations of the materials, since the material can not

originate its own changes: οὐ γὰρ δὴ τό γε ὑποκείμενον αὐτὸ ποιεὶ

μεταβάλλειν ἑαῦτο; λέγω δ᾽ οἰον οὐτε τὸ ξύλον οὔτε ὁ χαλκὸς αἴτιος

τοῦ μεταβάλλειν ἑκάτερον αὐτῶν, οὐδὲ ποιεῖ τὸ μὲν ξύλον κλίνην ὁ

δέ χαλκὸς ἀνδριάντα, ἀλλ᾽ ἑτερόν τι τῆς μεταβολῆς αἴτιον, viz.,

the other kind of cause, ὄθεν ἡ ἀρχὴ τῆς κινήσεως—an Efficient

Cause. Aristotle expresses great approbation of this doctrine

(which he says made its author appear the only sober man among

persons raving, οἰον νήφων ἐφάνη παρ᾽ εἰκῆ λέγοντας τοῦς

πρότερον); but while describing the influence which it exercised

over subsequent speculation, he remarks that the philosophers

against whom this, as he thinks, insuperable difficulty was urged,

had not felt it to be any difficulty: οὐδέν ἐδυσχεράναν ἐν

ἑαυτοῖς. It is surely unnecessary to say more in proof of the

matter of fact which Dr. Tulloch and his reviewer disbelieve.

Having pointed out what he thinks the error of these early

speculators in not recognizing the need of an efficient cause,

Aristotle goes on to mention two other efficient causes to which

they might have had recourse, instead of intelligence: τύχη,

chance, and τὸ αὐτομάτον, spontaneity. He indeed puts these aside

as not sufficiently worthy causes for the order in the universe,

οὐδ᾽ αὑ τωῷ αὐτομάτῳ καὶ τῇ τύχῃ τοσοῦτον ἐπιτρέψαι πρᾶγμα καλῶς

εἰχεν; but he does not reject them as incapable of producing _any_

effect, but only as incapable of producing _that_ effect. He

himself recognizes τύχη and τὸ αὐτομάτον as co-ordinate agents

with Mind in producing the phenomena of the universe; the

department allotted to them being composed of all the classes of

phenomena which are not supposed to follow any uniform law. By

thus including Chance among efficient causes, Aristotle fell into

an error which philosophy has now outgrown, but which is by no

means so alien to the spirit even of modern speculation as it may

at first sight appear. Up to quite a recent period philosophers

went on ascribing, and many of them have not yet ceased to

ascribe, a real existence to the results of abstraction. Chance

could make out as good a title to that dignity as many other of

the mind’s abstract creations: it had had a name given to it, and

why should it not be a reality? As for τὸ αὐτομάτον, it is

recognized even yet as one of the modes of origination of

phenomena by all those thinkers who maintain what is called the

Freedom of the Will. The same self-determining power which that

doctrine attributes to volitions, was supposed by the ancients to

be possessed also by some other natural phenomena: a circumstance

which throws considerable light on more than one of the supposed

invincible necessities of belief. I have introduced it here,

because this belief of Aristotle, or rather of the Greek

philosophers generally, is as fatal as the doctrines of Thales and

the Ionic school to the theory that the human mind is compelled by

its constitution to conceive volition as the origin of all force,

and the efficient cause of all phenomena.(130)

With regard to the modern philosophers (Leibnitz and the

Cartesians) whom I had cited as having maintained that the action

of mind upon matter, so far from being the only conceivable origin

of material phenomena, is itself inconceivable; the attempt to

rebut this argument by asserting that the mode, not the fact, of

the action of mind on matter was represented as inconceivable, is

an abuse of the privilege of writing confidently about authors

without reading them; for any knowledge whatever of Leibnitz would

have taught those who thus speak of him, that the inconceivability

of the mode, and the impossibility of the thing, were in his mind

convertible expressions. What was his famous Principle of the

Sufficient Reason, the very corner-stone of his Philosophy, from

which the Pre-established Harmony, the doctrine of Monads, and all

the opinions most characteristic of Leibnitz, were corollaries? It

was, that nothing exists, the existence of which is not capable of

being proved and explained _a priori_; the proof and explanation

in the case of contingent facts being derived from the nature of

their causes; which could not be the causes unless there was

something in their nature showing them to be capable of producing

those particular effects. And this “something” which accounts for

the production of physical effects, he was able to find in many

physical causes, but could not find it in any finite minds, which

therefore he unhesitatingly asserted to be incapable of producing

any physical effects whatever. “On ne saurait concevoir,” he says,

“une action réciproque de la matière et de l’intelligence l’une

sur l’autre,” and there is therefore (he contends) no choice but

between the Occasional Causes of the Cartesians and his own

Pre-established Harmony, according to which there is no more

connection between our volitions and our muscular actions than

there is between two clocks which are wound up to strike at the

same instant. But he felt no similar difficulty as to physical

causes; and throughout his speculations, as in the passage I have

already cited respecting gravitation, he distinctly refuses to

consider as part of the order of nature any fact which is not

explicable from the nature of its physical cause.

With regard to the Cartesians (not Descartes; I did not make that

mistake, though the reviewer of Dr. Tulloch’s Essay attributes it

to me) I take a passage almost at random from Malebranche, who is

the best known of the Cartesians, and, though not the inventor of

the system of Occasional Causes, is its principal expositor. In

Part II., chap. iii., of his Sixth Book, having first said that

matter can not have the power of moving itself, he proceeds to

argue that neither can mind have the power of moving it. “Quand on

examine l’idée que l’on a de tous les esprits finis, on ne voit

point de liaison nécessaire entre leur volonté et le mouvement de

quelque corps que ce soit, on voit au contraire qu’il n’y en a

point, et qu’il n’y en peut avoir” (there is nothing in the idea

of finite mind which can account for its causing the motion of a

body); “on doit aussi conclure, si on vent raisonner selon ses

lumières, qu’il n’y a aucun esprit créé qui puisse remuer quelque

corps que ce soit comme cause véritable on principale, de même que

l’on a dit qu’aucun corps ne se pouvait remuer soi-même:” thus the

idea of Mind is according to him as incompatible as the idea of

Matter with the exercise of active force. But when, he continues,

we consider not a created but a Divine Mind, the case is altered;

for the idea of a Divine Mind includes omnipotence; and the idea

of omnipotence does contain the idea of being able to move bodies.

Thus it is the nature of omnipotence which renders the motion of

bodies even by the Divine Mind credible or conceivable, while, so

far as depended on the mere nature of mind, it would have been

inconceivable and incredible. If Malebranche had not believed in

an omnipotent Being, he would have held all action of mind on body

to be a demonstrated impossibility.(131)

A doctrine more precisely the reverse of the Volitional theory of

causation can not well be imagined. The Volitional theory is, that

we know by intuition or by direct experience the action of our own

mental volitions on matter; that we may hence infer all other

action upon matter to be that of volition, and might thus know,

without any other evidence, that matter is under the government of

a Divine Mind. Leibnitz and the Cartesians, on the contrary,

maintain that our volitions do not and can not act upon matter,

and that it is only the existence of an all-governing Being, and

that Being omnipotent, which can account for the sequence between

our volitions and our bodily actions. When we consider that each

of these two theories, which, as theories of causation, stand at

the opposite extremes of possible divergence from one another,

invokes not only as its evidence, but as its sole evidence, the

absolute inconceivability of any theory but itself, we are enabled

to measure the worth of this kind of evidence: and when we find

the Volitional theory entirely built upon the assertion that by

our mental constitution we are compelled to recognize our

volitions as efficient causes, and then find other thinkers

maintaining that we know that they are not and can not be such

causes, and can not conceive them to be so, I think we have a

right to say that this supposed law of our mental constitution

does not exist.

Dr. Tulloch (pp. 45–47) thinks it a sufficient answer to this,

that Leibnitz and the Cartesians were Theists, and believed the

will of God to be an efficient cause. Doubtless they did, and the

Cartesians even believed (though Leibnitz did not) that it is the

only such cause. Dr. Tulloch mistakes the nature of the question.

I was not writing on Theism, as Dr. Tulloch is, but against a

particular theory of causation, which, if it be unfounded, can

give no effective support to Theism or to any thing else. I found

it asserted that volition is the only efficient cause, on the

ground that no other efficient cause is conceivable. To this

assertion I oppose the instances of Leibnitz and of the

Cartesians, who affirmed with equal positiveness that volition as

an efficient cause is itself not conceivable, and that

omnipotence, which renders all things conceivable, can alone take

away the impossibility. This I thought, and think, a conclusive

answer to the argument on which this theory of causation avowedly

depends. But I certainly did not imagine that Theism was bound up

with that theory; nor expected to be charged with denying Leibnitz

and the Cartesians to be Theists because I denied that they held

the theory.