We may observe the same effect of poetry in a lesser degree; and this is

common both to poetry and madness, that the vivacity they bestow on the

ideas is not derived from the particular situations or connexions of the

objects of these ideas, but from the present temper and disposition

of the person. But how great soever the pitch may be, to which this

vivacity rises, it is evident, that in poetry it never has the same

feeling with that which arises in the mind, when we reason, though even

upon the lowest species of probability. The mind can easily distinguish

betwixt the one and the other; and whatever emotion the poetical

enthusiasm may give to the spirits, it is still the mere phantom of

belief or persuasion. The case is the same with the idea, as with the

passion it occasions. There is no passion of the human mind but what may

arise from poetry; though at the same time the feelings of the passions

are very different when excited by poetical fictions, from what they are

when they are from belief and reality. A passion, which is disagreeable

in real life, may afford the highest entertainment in a tragedy, or epic

poem. In the latter case, it lies not with that weight upon us: It

feels less firm and solid: And has no other than the agreeable effect of

exciting the spirits, and rouzing the attention. The difference in the

passions is a clear proof of a like difference in those ideas, from

which the passions are derived. Where the vivacity arises from a

customary conjunction with a present impression; though the imagination

may not, in appearance, be so much moved; yet there is always something

more forcible and real in its actions, than in the fervors of poetry and

eloquence. The force of our mental actions in this case, no more than in

any other, is not to be measured by the apparent agitation of the mind.

A poetical description may have a more sensible effect on the

fancy, than an historical narration. It may collect more of those

circumstances, that form a compleat image or picture. It may seem to

set the object before us in more lively colours. But still the ideas it

presents are different to the feeling from those, which arise from the

memory and the judgment. There is something weak and imperfect amidst

all that seeming vehemence of thought and sentiment, which attends the

fictions of poetry.

We shall afterwards have occasion to remark both the resemblance and

differences betwixt a poetical enthusiasm, and a serious conviction. In

the mean time I cannot forbear observing, that the great difference

in their feeling proceeds in some measure from reflection and GENERAL

RULES. We observe, that the vigour of conception, which fictions receive

from poetry and eloquence, is a circumstance merely accidental, of which

every idea is equally susceptible; and that such fictions are connected

with nothing that is real. This observation makes us only lend

ourselves, so to speak, to the fiction: But causes the idea to feel very

different from the eternal established persuasions founded on memory and

custom. They are somewhat of the same kind: But the one is much inferior

to the other, both in its causes and effects.

A like reflection on general rules keeps us from augmenting our belief

upon every encrease of the force and vivacity of our ideas. Where an

opinion admits of no doubt, or opposite probability, we attribute to it

a full conviction: though the want of resemblance, or contiguity, may

render its force inferior to that of other opinions. It is thus the

understanding corrects the appearances of the senses, and makes us

imagine, that an object at twenty foot distance seems even to the eye as

large as one of the same dimensions at ten.

We may observe the same effect of poetry in a lesser degree; only with

this difference, that the least reflection dissipates the illusions

of poetry, and Places the objects in their proper light. It is however

certain, that in the warmth of a poetical enthusiasm, a poet has a

counterfeit belief, and even a kind of vision of his objects: And

if there be any shadow of argument to support this belief, nothing

contributes more to his full conviction than a blaze of poetical figures

and images, which have their effect upon the poet himself, as well as

upon his readers.

SECT. XI. OF THE PROBABILITY OF CHANCES.

But in order to bestow on this system its full force and evidence, we

must carry our eye from it a moment to consider its consequences, and

explain from the same principles some other species of reasoning, which

are derived from the same origin.

Those philosophers, who have divided human reason into knowledge and

probability, and have defined the first to be that evidence, which

arises from the comparison of ideas, are obliged to comprehend all our

arguments from causes or effects under the general term of probability.

But though every one be free to use his terms in what sense he pleases;

and accordingly in the precedent part of this discourse, I have followed

this method of expression; it is however certain, that in common

discourse we readily affirm, that many arguments from causation exceed

probability, and may be received as a superior kind of evidence. One

would appear ridiculous, who would say, that it is only probable the

sun will rise to-morrow, or that all men must dye; though it is plain we

have no further assurance of these facts, than what experience affords

us. For this reason, it would perhaps be more convenient, in order at

once to preserve the common signification of words, and mark the several

degrees of evidence, to distinguish human reason into three kinds, viz.

THAT FROM KNOWLEDGE, FROM PROOFS, AND FROM PROBABILITIES. By knowledge,

I mean the assurance arising from the comparison of ideas. By proofs,

those arguments, which are derived from the relation of cause and

effect, and which are entirely free from doubt and uncertainty. By

probability, that evidence, which is still attended with uncertainty. It

is this last species of reasoning, I proceed to examine.

Probability or reasoning from conjecture may be divided into two kinds,

viz. that which is founded on chance, and that which arises from causes.

We shall consider each of these in order.

The idea of cause and effect is derived from experience, which

presenting us with certain objects constantly conjoined with each other,

produces such a habit of surveying them in that relation, that we cannot

without a sensible violence survey them iii any other. On the other

hand, as chance is nothing real in itself, and, properly speaking, is

merely the negation of a cause, its influence on the mind is contrary to

that of causation; and it is essential to it, to leave the imagination

perfectly indifferent, either to consider the existence or non-existence

of that object, which is regarded as contingent. A cause traces the

way to our thought, and in a manner forces us to survey such certain

objects, in such certain relations. Chance can only destroy this

determination of the thought, and leave the mind in its native situation

of indifference; in which, upon the absence of a cause, it is instantly

re-instated.

Since therefore an entire indifference is essential to chance, no one

chance can possibly be superior to another, otherwise than as it is

composed of a superior number of equal chances. For if we affirm that

one chance can, after any other manner, be superior to another, we must

at the same time affirm, that there is something, which gives it the

superiority, and determines the event rather to that side than the

other: That is, in other words, we must allow of a cause, and destroy

the supposition of chance; which we had before established. A

perfect and total indifference is essential to chance, and one total

indifference can never in itself be either superior or inferior to

another. This truth is not peculiar to my system, but is acknowledged by

every one, that forms calculations concerning chances.

And here it is remarkable, that though chance and causation be directly

contrary, yet it is impossible for us to conceive this combination of

chances, which is requisite to render one hazard superior to another,

without supposing a mixture of causes among the chances, and a

conjunction of necessity in some particulars, with a total indifference

in others. Where nothing limits the chances, every notion, that the most

extravagant fancy can form, is upon a footing of equality; nor can there

be any circumstance to give one the advantage above another. Thus unless

we allow, that there are some causes to make the dice fall, and preserve

their form in their fall, and lie upon some one of their sides, we can

form no calculation concerning the laws of hazard. But supposing these

causes to operate, and supposing likewise all the rest to be indifferent

and to be determined by chance, it is easy to arrive at a notion of a

superior combination of chances. A dye that has four sides marked with

a certain number of spots, and only two with another, affords us an

obvious and easy instance of this superiority. The mind is here limited

by the causes to such a precise number and quality of the events; and at

the same time is undetermined in its choice of any particular event.

Proceeding then in that reasoning, wherein we have advanced three steps;

that chance is merely the negation of a cause, and produces a total

indifference in the mind; that one negation of a cause and one total

indifference can never be superior or inferior to another; and that

there must always be a mixture of causes among the chances, in order to

be the foundation of any reasoning: We are next to consider what effect

a superior combination of chances can have upon the mind, and after what

manner it influences our judgment and opinion. Here we may repeat all

the same arguments we employed in examining that belief, which arises

from causes; and may prove, after the same manner, that a superior

number of chances produces our assent neither by demonstration nor

probability. It is indeed evident that we can never by the comparison

of mere ideas make any discovery, which can be of consequence in this

affairs and that it is impossible to prove with certainty, that any

event must fall on that side where there is a superior number of

chances. To, suppose in this case any certainty, were to overthrow what

we have established concerning the opposition of chances, and their

perfect equality and indifference.

Should it be said, that though in an opposition of chances it is

impossible to determine with certainty, on which side the event will

fall, yet we can pronounce with certainty, that it is more likely and

probable, it will be on that side where there is a superior number of

chances, than where there is an inferior: should this be said, I would

ask, what is here meant by likelihood and probability? The likelihood

and probability of chances is a superior number of equal chances; and

consequently when we say it is likely the event win fall on the side,

which is superior, rather than on the inferior, we do no more than

affirm, that where there is a superior number of chances there is

actually a superior, and where there is an inferior there is an

inferior; which are identical propositions, and of no consequence. The

question is, by what means a superior number of equal chances operates

upon the mind, and produces belief or assent; since it appears, that

it is neither by arguments derived from demonstration, nor from

probability.

In order to clear up this difficulty, we shall suppose a person to take

a dye, formed after such a manner as that four of its sides are marked

with one figure, or one number of spots, and two with another; and to

put this dye into the box with an intention of throwing it: It is plain,

he must conclude the one figure to be more probable than the other, and

give the preference to that which is inscribed on the greatest number

of sides. He in a manner believes, that this will lie uppermost; though

still with hesitation and doubt, in proportion to the number of chances,

which are contrary: And according as these contrary chances diminish,

and the superiority encreases on the other side, his belief acquires new

degrees of stability and assurance. This belief arises from an operation

of the mind upon the simple and limited object before us; and therefore

its nature will be the more easily discovered and explained. We have

nothing but one single dye to contemplate, in order to comprehend one of

the most curious operations of the understanding.

This dye, formed as above, contains three circumstances worthy of our

attention. First, Certain causes, such as gravity, solidity, a cubical

figure, &c. which determine it to fall, to preserve its form in its

fall, and to turn up one of its sides. Secondly, A certain number

of sides, which are supposed indifferent. Thirdly, A certain figure

inscribed on each side. These three particulars form the whole nature of

the dye, so far as relates to our present purpose; and consequently are

the only circumstances regarded by the mind in its forming a judgment

concerning the result of such a throw. Let us, therefore, consider

gradually and carefully what must be the influence of these

circumstances on the thought and imagination.

First, We have already observed, that the mind is determined by custom

to pass from any cause to its effect, and that upon the appearance

of the one, it is almost impossible for it not to form an idea of the

other. Their constant conjunction in past instances has produced such

a habit in the mind, that it always conjoins them in its thought, and

infers the existence of the one from that of its usual attendant. When

it considers the dye as no longer supported by the box, it can not

without violence regard it as suspended in the air; but naturally places

it on the table, and views it as turning up one of its sides. This

is the effect of the intermingled causes, which are requisite to our

forming any calculation concerning chances.

Secondly, It is supposed, that though the dye be necessarily determined

to fall, and turn up one of its sides, yet there is nothing to fix the

particular side, but that this is determined entirely by chance. The

very nature and essence of chance is a negation of causes, and the

leaving the mind in a perfect indifference among those events, which

are supposed contingent. When therefore the thought is determined by the

causes to consider the dye as falling and turning up one of its sides,

the chances present all these sides as equal, and make us consider every

one of them, one after another, as alike probable and possible. The

imagination passes from the cause, viz. the throwing of the dye, to the

effect, viz. the turning up one of the six sides; and feels a kind of

impossibility both of stopping short in the way, and of forming any

other idea. But as all these six sides are incompatible, and the dye

cannot turn up above one at once, this principle directs us not to

consider all of them at once as lying uppermost; which we look upon

as impossible: Neither does it direct us with its entire force to any

particular side; for in that case this side would be considered as

certain and inevitable; but it directs us to the whole six sides after

such a manner as to divide its force equally among them. We conclude in

general, that some one of them must result from the throw: We run all

of them over in our minds: The determination of the thought is common to

all; but no more of its force falls to the share of any one, than what

is suitable to its proportion with the rest. It is after this manner the

original impulse, and consequently the vivacity of thought, arising from

the causes, is divided and split in pieces by the intermingled chances.

We have already seen the influence of the two first qualities of the

dye, viz. the causes, and the number and indifference of the sides, and

have learned how they give an impulse to the thought, and divide that

impulse into as many parts as there are unites in the number of sides.

We must now consider the effects of the third particular, viz. the

figures inscribed on each side. It is evident that where several

sides have the same figure inscribe on them, they must concur in their

influence on the mind, and must unite upon one image or idea of a figure

all those divided impulses, that were dispersed over the several sides,

upon which that figure is inscribed. Were the question only what side

will be turned up, these are all perfectly equal, and no one could ever

have any advantage above another. But as the question is concerning the

figure, and as the same figure is presented by more than one side: it is

evident, that the impulses belonging to all these sides must re-unite

in that one figure, and become stronger and more forcible by the union.

Four sides are supposed in the present case to have the same figure

inscribed on them, and two to have another figure. The impulses of

the former are, therefore, superior to those of the latter. But as the

events are contrary, and it is impossible both these figures can be

turned up; the impulses likewise become contrary, and the inferior

destroys the superior, as far as its strength goes. The vivacity of the

idea is always proportionable to the degrees of the impulse or tendency

to the transition; and belief is the same with the vivacity of the idea,

according to the precedent doctrine.

SECT. XII. OF THE PROBABILITY OF CAUSES.

What I have said concerning the probability of chances can serve to

no other purpose, than to assist us in explaining the probability of

causes; since it is commonly allowed by philosophers, that what the

vulgar call chance is nothing but a secret and concealed cause. That

species of probability, therefore, is what we must chiefly examine.

The probabilities of causes are of several kinds; but are all derived

from the same origin, viz. THE ASSOCIATION OF IDEAS TO A PRESENT

IMPRESSION. As the habit, which produces the association, arises from

the frequent conjunction of objects, it must arrive at its perfection by

degrees, and must acquire new force from each instance, that falls under

our observation. The first instance has little or no force: The second

makes some addition to it: The third becomes still more sensible; and it

is by these slow steps, that our judgment arrives at a full assurance.

But before it attains this pitch of perfection, it passes through

several inferior degrees, and in all of them is only to be esteemed a

presumption or probability. The gradation, therefore, from probabilities

to proofs is in many cases insensible; and the difference betwixt these

kinds of evidence is more easily perceived in the remote degrees, than

in the near and contiguous.

It is worthy of remark on this occasion, that though the species of

probability here explained be the first in order, and naturally takes

place before any entire proof can exist, yet no one, who is arrived at

the age of maturity, can any longer be acquainted with it. It is true,

nothing is more common than for people of the most advanced knowledge

to have attained only an imperfect experience of many particular events;

which naturally produces only an imperfect habit and transition: But

then we must consider, that the mind, having formed another observation

concerning the connexion of causes and effects, gives new force to

its reasoning from that observation; and by means of it can build an

argument on one single experiment, when duly prepared and examined. What

we have found once to follow from any object, we conclude will for ever

follow from it; and if this maxim be not always built upon as certain,

it is not for want of a sufficient number of experiments, but because

we frequently meet with instances to the contrary; which leads us to

the second species of probability, where there is a contrariety in our

experience and observation.

It would be very happy for men in the conduct of their lives and

actions, were the same objects always conjoined together, and, we had

nothing to fear but the mistakes of our own judgment, without having any

reason to apprehend the uncertainty of nature. But as it is frequently

found, that one observation is contrary to another, and that causes and

effects follow not in the same order, of which we have I had experience,

we are obliged to vary our reasoning on, account of this uncertainty,

and take into consideration the contrariety of events. The first

question, that occurs on this head, is concerning the nature and causes

of the contrariety.

The vulgar, who take things according to their first appearance,

attribute the uncertainty of events to such an uncertainty in the

causes, as makes them often fail of their usual influence, though

they meet with no obstacle nor impediment in their operation. But

philosophers observing, that almost in every part of nature there is

contained a vast variety of springs and principles, which are hid,

by reason of their minuteness or remoteness, find that it is at least

possible the contrariety of events may not proceed from any contingency

in the cause, but from the secret operation of contrary causes. This

possibility is converted into certainty by farther observation, when

they remark, that upon an exact scrutiny, a contrariety of effects

always betrays a contrariety of causes, and proceeds from their mutual

hindrance and opposition. A peasant can give no better reason for the

stopping of any clock or watch than to say, that commonly it does not

go right: But an artizan easily perceives, that the same force in the

spring or pendulum has always the same influence on the wheels; but

fails of its usual effect, perhaps by reason of a grain of dust, which

puts a stop to the whole movement. From the observation of several

parallel instances, philosophers form a maxim, that the connexion

betwixt all causes and effects is equally necessary, and that its

seeming uncertainty in some instances proceeds from the secret

opposition of contrary causes.

But however philosophers and the vulgar may differ in their explication

of the contrariety of events, their inferences from it are always of the

same kind, and founded on the same principles. A contrariety of events

in the past may give us a kind of hesitating belief for the future after

two several ways. First, By producing an imperfect habit and transition

from the present impression to the related idea. When the conjunction of

any two objects is frequent, without being entirely constant, the mind

is determined to pass from one object to the other; but not with

so entire a habit, as when the union is uninterrupted, and all the

instances we have ever met with are uniform and of a piece-.. We find

from common experience, in our actions as well as reasonings, that

a constant perseverance in any course of life produces a strong

inclination and tendency to continue for the future; though there

are habits of inferior degrees of force, proportioned to the inferior

degrees of steadiness and uniformity in our conduct.

There is no doubt but this principle sometimes takes place, and

produces those inferences we draw from contrary phaenomena: though I

am perswaded, that upon examination we shall not find it to be the

principle, that most commonly influences the mind in this species of

reasoning. When we follow only the habitual determination of the mind,

we make the transition without any reflection, and interpose not a

moment's delay betwixt the view of one object and the belief of that,

which is often found to attend it. As the custom depends not upon any

deliberation, it operates immediately, without allowing any time for

reflection. But this method of proceeding we have but few instances

of in our probable reasonings; and even fewer than in those, which are

derived from the uninterrupted conjunction of objects. In the former

species of reasoning we commonly take knowingly into consideration

the contrariety of past events; we compare the different sides of the

contrariety, and carefully weigh the experiments, which we have on each

side: Whence we may conclude, that our reasonings of this kind arise

not directly from the habit, but in an oblique manner; which we must now

endeavour to explain.

It is evident, that when an object is attended with contrary effects, we

judge of them only by our past experience, and always consider those

as possible, which we have observed to follow from it. And as past

experience regulates our judgment concerning the possibility of these

effects, so it does that concerning their probability; and that effect,

which has been the most common, we always esteem the most likely. Here

then are two things to be considered, viz. the reasons which determine

us to make the past a standard for the future, and the manner how we

extract a single judgment from a contrariety of past events.

First we may observe, that the supposition, that the future resembles

the past, is not founded on arguments of any kind, but is derived

entirely from habit, by which we are determined to expect for the future

the same train of objects, to which we have been accustomed. This habit

or determination to transfer the past to the future is full and perfect;

and consequently the first impulse of the imagination in this species of

reasoning is endowed with the same qualities.

But, secondly, when in considering past experiments we find them of a

contrary nature, this determination, though full and perfect in itself,

presents us with no steady object, but offers us a number of disagreeing

images in a certain order and proportion. The first impulse, therefore,

is here broke into pieces, and diffuses itself over all those images, of

which each partakes an equal share of that force and vivacity, that is

derived from the impulse. Any of these past events may again happen;

and we judge, that when they do happen, they will be mixed in the same

proportion as in the past.

If our intention, therefore, be to consider the proportions of contrary

events in a great number of instances, the images presented by our past

experience must remain in their FIRST FORM, and preserve their first

proportions. Suppose, for instance, I have found by long observation,

that of twenty ships, which go to sea, only nineteen return. Suppose

I see at present twenty ships that leave the port: I transfer my past

experience to the future, and represent to myself nineteen of these

ships as returning in safety, and one as perishing. Concerning this

there can be no difficulty. But as we frequently run over those several

ideas of past events, in order to form a judgment concerning one single

event, which appears uncertain; this consideration must change the FIRST

FORM of our ideas, and draw together the divided images presented

by experience; since it is to it we refer the determination of that

particular event, upon which we reason. Many of these images are

supposed to concur, and a superior number to concur on one side. These

agreeing images unite together, and render the idea more strong and

lively, not only than a mere fiction of the imagination, but also than

any idea, which is supported by a lesser number of experiments. Each new

experiment is as a new stroke of the pencil, which bestows an additional

vivacity on the colours without either multiplying or enlarging the

figure. This operation of the mind has been so fully explained in

treating of the probability of chance, that I need not here endeavour to

render it more intelligible. Every past experiment may be considered as

a kind of chance; I it being uncertain to us, whether the object will

exist conformable to one experiment or another. And for this reason

every thing that has been said on the one subject is applicable to both.

Thus upon the whole, contrary experiments produce an imperfect belief,

either by weakening the habit, or by dividing and afterwards joining in

different parts, that perfect habit, which makes us conclude in general,

that instances, of which we have no experience, must necessarily

resemble those of which we have.

To justify still farther this account of the second species of

probability, where we reason with knowledge and reflection from

a contrariety of past experiments, I shall propose the following

considerations, without fearing to give offence by that air of subtilty,

which attends them. Just reasoning ought still, perhaps, to retain

its force, however subtile; in the same manner as matter preserves its

solidity in the air, and fire, and animal spirits, as well as in the

grosser and more sensible forms.

First, We may observe, that there is no probability so great as not to

allow of a contrary possibility; because otherwise it would cease to be

a probability, and would become a certainty. That probability of causes,

which is most extensive, and which we at present examine, depends on a

contrariety of experiments: and it is evident an experiment in the past

proves at least a possibility for the future.

Secondly, The component parts of this possibility and probability are of

the same nature, and differ in number only, but not in kind. It has been

observed, that all single chances are entirely equal, and that the

only circumstance, which can give any event, that is contingent, a

superiority over another is a superior number of chances. In like

manner, as the uncertainty of causes is discovery by experience, which

presents us with a view of contrary events, it is plain, that when we

transfer the past to the future, the known to the unknown, every past

experiment has the same weight, and that it is only a superior number

of them, which can throw the ballance on any side. The possibility,

therefore, which enters into every reasoning of this kind, is composed

of parts, which are of the same nature both among themselves, and with

those, that compose the opposite probability.

Thirdly, We may establish it as a certain maxim, that in all moral as

well as natural phaenomena, wherever any cause consists of a number

of parts, and the effect encreases or diminishes, according to the

variation of that number, the effects properly speaking, is a compounded

one, and arises from the union of the several effects, that proceed from

each part of the cause. Thus, because the gravity of a body encreases or

diminishes by the encrease or diminution of its parts, we conclude that

each part contains this quality and contributes to the gravity of the

whole. The absence or presence of a part of the cause is attended with

that of a proportionable part of the effect. This connexion or constant

conjunction sufficiently proves the one part to be the cause of the

other. As the belief which we have of any event, encreases or diminishes

according to the number of chances or past experiments, it is to be

considered as a compounded effect, of which each part arises from a

proportionable number of chances or experiments.

Let us now join these three observations, and see what conclusion we can

draw from them. To every probability there is an opposite possibility.

This possibility is composed of parts, that are entirely of the same

nature with those of the probability; and consequently have the same

influence on the mind and understanding. The belief, which attends the

probability, is a compounded effect, and is formed by the concurrence

of the several effects, which proceed from each part of the probability.

Since therefore each part of the probability contributes to the

production of the belief, each part of the possibility must have the

same influence on the opposite side; the nature of these parts being

entirely the same. The contrary belief, attending the possibility,

implies a view of a certain object, as well as the probability does

an opposite view. In this particular both these degrees of belief are

alike. The only manner then, in which the superior number of similar

component parts in the one can exert its influence, and prevail above

the inferior in the other, is by producing a stronger and more lively

view of its object. Each part presents a particular view; and all these

views uniting together produce one general view, which is fuller and

more distinct by the greater number of causes or principles, from which

it is derived.

The component parts of the probability and possibility, being alike

in their nature, must produce like effects; and the likeness of their

effects consists in this, that each of them presents a view of a

particular object. But though these parts be alike in their nature, they

are very different in their quantity and number; and this difference

must appear in the effect as well as the similarity. Now as the view

they present is in both cases full and entire, and comprehends the

object in all its parts, it is impossible that in this particular there

can be any difference; nor is there any thing but a superior vivacity

in the probability, arising from the concurrence of a superior number of

views, which can distinguish these effects.

Here is almost the same argument in a different light. All our

reasonings concerning the probability of causes are founded on the

transferring of past to future. The transferring of any past experiment

to the future is sufficient to give us a view of the object; whether

that experiment be single or combined with others of the same kind;

whether it be entire, or opposed by others of a contrary kind. Suppose,

then, it acquires both these qualities of combination and opposition, it

loses not upon that account its former power of presenting a view of the

object, but only concurs with and opposes other experiments, that have

a like influence. A question, therefore, may arise concerning the manner

both of the concurrence and opposition. As to the concurrence, there is

only the choice left betwixt these two hypotheses. First, That the view

of the object, occasioned by the transference of each past experiment,

preserves itself entire, and only multiplies the number of views. Or,

SECONDLY, That it runs into the other similar and correspondent views,

and gives them a superior degree of force and vivacity. But that the

first hypothesis is erroneous, is evident from experience, which

informs us, that the belief, attending any reasoning, consists in

one conclusion, not in a multitude of similar ones, which would only

distract the mind, and in many cases would be too numerous to be

comprehended distinctly by any finite capacity. It remains, therefore,

as the only reasonable opinion, that these similar views run into each

other, and unite their forces; so as to produce a stronger and clearer

view, than what arises from any one alone. This is the manner, in which

past experiments concur, when they are transfered to any future event.

As to the manner of their opposition, it is evident, that as the

contrary views are incompatible with each other, and it is impossible

the object can at once exist conformable to both of them, their

influence becomes mutually destructive, and the mind is determined to

the superior only with that force, which remains, after subtracting the

inferior.

I am sensible how abstruse all this reasoning must appear to the

generality of readers, who not being accustomed to such profound

reflections on the intellectual faculties of the mind, will be apt to

reject as chimerical whatever strikes not in with the common received

notions, and with the easiest and most obvious principles of philosophy.

And no doubt there are some pains required to enter into these

arguments; though perhaps very little are necessary to perceive the

imperfection of every vulgar hypothesis on this subject, and the little

light, which philosophy can yet afford us in such sublime and such

curious speculations. Let men be once fully perswaded of these two

principles, THAT THERE, IS NOTHING IN ANY OBJECT, CONSIDERED IN ITSELF,

WHICH CAN AFFORD US A REASON FOR DRAWING A CONCLUSION BEYOND it; and,

THAT EVEN AFTER THE OBSERVATION OF THE FREQUENT OR CONSTANT CONJUNCTION

OF OBJECTS, WE HAVE NO REASON TO DRAW ANY INFERENCE CONCERNING ANY

OBJECT BEYOND THOSE OF WHICH WE HAVE HAD EXPERIENCE; I say, let men be

once fully convinced of these two principles, and this will throw them

so loose from all common systems, that they will make no difficulty of

receiving any, which may appear the most extraordinary. These principles

we have found to be sufficiently convincing, even with regard to our

most certain reasonings from causation: But I shall venture to affirm,

that with regard to these conjectural or probable reasonings they still

acquire a new degree of evidence.

First, It is obvious, that in reasonings of this kind, it is not the

object presented to us, which, considered in itself, affords us any

reason to draw a conclusion concerning any other object or event. For

as this latter object is supposed uncertain, and as the uncertainty is

derived from a concealed contrariety of causes in the former, were any

of the causes placed in the known qualities of that object, they would

no longer be concealed, nor would our conclusion be uncertain.

But, secondly, it is equally obvious in this species of reasoning, that

if the transference of the past to the future were founded merely on a

conclusion of the understanding, it could never occasion any belief or

assurance. When we transfer contrary experiments to the future, we

can only repeat these contrary experiments with their particular

proportions; which could not produce assurance in any single event, upon

which we reason, unless the fancy melted together all those images

that concur, and extracted from them one single idea or image, which is

intense and lively in proportion to the number of experiments from which

it is derived, and their superiority above their antagonists. Our past

experience presents no determinate object; and as our belief, however

faint, fixes itself on a determinate object, it is evident that the

belief arises not merely from the transference of past to future, but

from some operation of the fancy conjoined with it. This may lead us

to conceive the manner, in which that faculty enters into all our

reasonings.

I shall conclude this subject with two reflections, which may deserve

our attention. The FIRST may be explained after this manner. When the

mind forms a reasoning concerning any matter of fact, which is

only probable, it casts its eye backward upon past experience, and

transferring it to the future, is presented with so many contrary

views of its object, of which those that are of the same kind uniting

together, and running into one act of the mind, serve to fortify and

inliven it. But suppose that this multitude of views or glimpses of an

object proceeds not from experience, but from a voluntary act of the

imagination; this effect does not follow, or at least, follows not in

the same degree. For though custom and education produce belief by such

a repetition, as is not derived from experience, yet this requires

a long tract of time, along with a very frequent and undesigned

repetition. In general we may pronounce, that a person who would

voluntarily repeat any idea in his mind, though supported by one past

experience, would be no more inclined to believe the existence of its

object, than if he had contented himself with one survey of it.

Beside the effect of design; each act of the mind, being separate and

independent, has a separate influence, and joins not its force with that

of its fellows. Not being united by any common object, producing them,

they have no relation to each other; and consequently make no transition

or union of forces. This phænomenon we shall understand better

afterwards.

My second reflection is founded on those large probabilities, which the

mind can judge of, and the minute differences it can observe betwixt

them. When the chances or experiments on one side amount to ten

thousand, and on the other to ten thousand and one, the judgment gives

the preference to the latter, upon account of that superiority; though

it is plainly impossible for the mind to run over every particular view,

and distinguish the superior vivacity of the image arising from the

superior number, where the difference is so inconsiderable. We have a

parallel instance in the affections. It is evident, according to the

principles above-mentioned, that when an object produces any passion in

us, which varies according to the different quantity of the object; I

say, it is evident, that the passion, properly speaking, is not a simple

emotion, but a compounded one, of a great number of weaker passions,

derived from a view of each part of the object. For otherwise it were

impossible the passion should encrease by the encrease of these parts.

Thus a man, who desires a thousand pound, has in reality a thousand

or more desires which uniting together, seem to make only one passion;

though the composition evidently betrays itself upon every alteration of

the object, by the preference he gives to the larger number, if superior

only by an unite. Yet nothing can be more certain, than that so small

a difference would not be discernible in the passions, nor could render

them distinguishable from each other. The difference, therefore, of our

conduct in preferring the greater number depends not upon our passions,

but upon custom, and general rules. We have found in a multitude of

instances, that the augmenting the numbers of any sum augments the

passion, where the numbers are precise and the difference sensible. The

mind can perceive from its immediate feeling, that three guineas produce

a greater passion than two; and this it transfers to larger numbers,

because of the resemblance; and by a general rule assigns to a thousand

guineas, a stronger passion than to nine hundred and ninety nine. These

general rules we shall explain presently.

But beside these two species of probability, which are derived from an

imperfect experience and from contrary causes, there is a third arising

from ANALOGY, which differs from them in some material circumstances.

According to the hypothesis above explained all kinds of reasoning from

causes or effects are founded on two particulars, viz., the constant

conjunction of any two objects in all past experience, and the

resemblance of a present object to any one of them. The effect of these

two particulars is, that the present object invigorates and inlivens the

imagination; and the resemblance, along with the constant union, conveys

this force and vivacity to the related idea; which we are therefore said

to believe, or assent to. If you weaken either the union or resemblance,

you weaken the principle of transition, and of consequence that belief,

which arises from it. The vivacity of the first impression cannot be

fully conveyed to the related idea, either where the conjunction of

their objects is not constant, or where the present impression does

not perfectly resemble any of those, whose union we are accustomed to

observe. In those probabilities of chance and causes above-explained,

it is the constancy of the union, which is diminished; and in the

probability derived from analogy, it is the resemblance only, which is

affected. Without some degree of resemblance, as well as union, it is

impossible there can be any reasoning: but as this resemblance admits

of many different degrees, the reasoning becomes proportionably more

or less firm and certain. An experiment loses of its force, when

transferred to instances, which are not exactly resembling; though it

is evident it may still retain as much as may be the foundation of

probability, as long as there is any resemblance remaining.

SECT. XIII. OF UNPHILOSOPHICAL PROBABILITY.

All these kinds of probability are received by philosophers, and allowed

to be reasonable foundations of belief and opinion. But there are

others, that are derived from the same principles, though they have not

had the good fortune to obtain the same sanction. The first probability

of this kind may be accounted for thus. The diminution of the union, and

of the resemblance, as above explained, diminishes the facility of the

transition, and by that means weakens the evidence; and we may farther

observe, that the same diminution of the evidence will follow from a

diminution of the impression, and from the shading of those colours,

under which it appears to the memory or senses. The argument, which

we found on any matter of fact we remember, is more or less convincing

according as the fact is recent or remote; and though the difference

in these degrees of evidence be not received by philosophy as solid and

legitimate; because in that case an argument must have a different force

to day, from what it shall have a month hence; yet notwithstanding

the opposition of philosophy, it is certain, this circumstance has a

considerable influence on the understanding, and secretly changes the

authority of the same argument, according to the different times,

in which it is proposed to us. A greater force and vivacity in the

impression naturally conveys a greater to the related idea; and it is on

the degrees of force and vivacity, that the belief depends, according to

the foregoing system.

There is a second difference, which we may frequently observe in our

degrees of belief and assurance, and which never fails to take place,

though disclaimed by philosophers. An experiment, that is recent and

fresh in the memory, affects us more than one that is in some measure

obliterated; and has a superior influence on the judgment, as well as on

the passions. A lively impression produces more assurance than a faint

one; because it has more original force to communicate to the related

idea, which thereby acquires a greater force and vivacity. A recent

observation has a like effect; because the custom and transition is

there more entire, and preserves better the original force in the

communication. Thus a drunkard, who has seen his companion die of a

debauch, is struck with that instance for some time, and dreads a like

accident for himself: But as the memory of it decays away by degrees,

his former security returns, and the danger seems less certain and real.

I add, as a third instance of this kind, that though our reasonings from

proofs and from probabilities be considerably different from each other,

yet the former species of reasoning often degenerates insensibly into

the latter, by nothing but the multitude of connected arguments. It is

certain, that when an inference is drawn immediately from an object,

without any intermediate cause or effect, the conviction is much

stronger, and the persuasion more lively, than when the imagination is

carryed through a long chain of connected arguments, however infallible

the connexion of each link may be esteemed. It is from the original

impression, that the vivacity of all the ideas is derived, by means

of the customary transition of the imagination; and it is evident this

vivacity must gradually decay in proportion to the distance, and must

lose somewhat in each transition. Sometimes this distance has a greater

influence than even contrary experiments would have; and a man may

receive a more lively conviction from a probable reasoning, which is

close and immediate, than from a long chain of consequences, though just

and conclusive in each part. Nay it is seldom such reasonings produce

any conviction; and one must have a very strong and firm imagination

to preserve the evidence to the end, where it passes through so many,

stages.

But here it may not be amiss to remark a very curious phænomenon, which

the present subject suggests to us. It is evident there is no point

of ancient history, of which we can have any assurance, but by passing

through many millions of causes and effects, and through a chain of

arguments of almost an immeasurable length. Before the knowledge of the

fact could come to the first historian, it must be conveyed through many

mouths; and after it is committed to writing, each new copy is a new

object, of which the connexion with the foregoing is known only by

experience and observation. Perhaps, therefore, it may be concluded from

the precedent reasoning, that the evidence of all ancient history must

now be lost; or at least, will be lost in time, as the chain of causes

encreases, and runs on to a greater length. But as it seems contrary to

common sense to think, that if the republic of letters, and the art of

printing continue on the same footing as at present, our posterity, even

after a thousand ages, can ever doubt if there has been such a man as

JULIUS CAESAR; this may be considered as an objection to the present

system. If belief consisted only in a certain vivacity, conveyed from an

original impression, it would decay by the length of the transition, and

must at last be utterly extinguished: And vice versa, if belief on some

occasions be not capable of such an extinction; it must be something

different from that vivacity.

Before I answer this objection I shall observe, that from this topic

there has been borrowed a very celebrated argument against the

Christian Religion; but with this difference, that the connexion

betwixt each link of the chain in human testimony has been there

supposed not to go beyond probability, and to be liable to a degree of

doubt and uncertainty. And indeed it must be confest, that in this

manner of considering the subject, (which however is not a true one)

there is no history or tradition, but what must in the end lose all its

force and evidence. Every new probability diminishes the original

conviction; and however great that conviction may be supposed, it is

impossible it can subsist under such re-iterated diminutions. This is

true in general; though we shall find afterwards,[9] that there is one

very memorable exception, which is of vast consequence in the present

subject of the understanding.

[9] Part IV. Sect. 1.

Mean while to give a solution of the preceding objection upon the

supposition, that historical evidence amounts at first to an entire

proof; let us consider, that though the links are innumerable, that

connect any original fact with the present impression, which is the

foundation of belief; yet they are all of the same kind, and depend on

the fidelity of Printers and Copyists. One edition passes into another,

and that into a third, and so on, till we come to that volume we peruse

at present. There is no variation in the steps. After we know one we

know all of them; and after we have made one, we can have no scruple as

to the rest. This circumstance alone preserves the evidence of history,

and will perpetuate the memory of the present age to the latest

posterity. If all the long chain of causes and effects, which connect

any past event with any volume of history, were composed of parts

different from each other, and which it were necessary for the mind

distinctly to conceive, it is impossible we should preserve to the

end any belief or evidence. But as most of these proofs are perfectly

resembling, the mind runs easily along them, jumps from one part to

another with facility, and forms but a confused and general notion of

each link. By this means a long chain of argument, has as little effect

in diminishing the original vivacity, as a much shorter would have, if

composed of parts, which were different from each other, and of which

each required a distinct consideration.

A fourth unphilosophical species of probability is that derived from

general rules, which we rashly form to ourselves, and which are the

source of what we properly call PREJUDICE. An IRISHMAN cannot have

wit, and a Frenchman cannot have solidity; for which reason, though the

conversation of the former in any instance be visibly very agreeable,

and of the latter very judicious, we have entertained such a prejudice

against them, that they must be dunces or fops in spite of sense and

reason. Human nature is very subject to errors of this kind; and perhaps

this nation as much as any other.

Should it be demanded why men form general rules, and allow them to

influence their judgment, even contrary to present observation and

experience, I should reply, that in my opinion it proceeds from those

very principles, on which all judgments concerning causes and effects

depend. Our judgments concerning cause and effect are derived from

habit and experience; and when we have been accustomed to see one object

united to another, our imagination passes from the first to the second,

by a natural transition, which precedes reflection, and which cannot be

prevented by it. Now it is the nature of custom not only to operate with

its full force, when objects are presented, that are exactly the same

with those to which we have been accustomed; but also to operate in an

inferior degree, when we discover such as are similar; and though the

habit loses somewhat of its force by every difference, yet it is seldom

entirely destroyed, where any considerable circumstances remain the

same. A man, who has contracted a custom of eating fruit by the use of

pears or peaches, will satisfy himself with melons, where he cannot find

his favourite fruit; as one, who has become a drunkard by the use of

red wines, will be carried almost with the same violence to white, if

presented to him. From this principle I have accounted for that species

of probability, derived from analogy, where we transfer our experience

in past instances to objects which are resembling, but are not exactly

the same with those concerning which we have had experience. In

proportion as the resemblance decays, the probability diminishes;

but still has some force as long as there remain any traces of the

resemblance.

This observation we may carry farther; and may remark, that though

custom be the foundation of all our judgments, yet sometimes it has an

effect on the imagination in opposition to the judgment, and produces

a contrariety in our sentiments concerning the same object. I explain

myself. In almost all kinds of causes there is a complication of

circumstances, of which some are essential, and others superfluous; some

are absolutely requisite to the production of the effect, and others

are only conjoined by accident. Now we may observe, that when these

superfluous circumstances are numerous, and remarkable, and frequently

conjoined with the essential, they have such an influence on the

imagination, that even in the absence of the latter they carry us on to

the conception of the usual effect, and give to that conception a force

and vivacity, which make it superior to the mere fictions of the fancy.

We may correct this propensity by a reflection on the nature of those

circumstances: but it is still certain, that custom takes the start, and

gives a biass to the imagination.

To illustrate this by a familiar instance, let us consider the case of

a man, who, being hung out from a high tower in a cage of iron cannot

forbear trembling, when he surveys the precipice below him, though he

knows himself to be perfectly secure from falling, by his experience of

the solidity of the iron, which supports him; and though the ideas of

fall and descent, and harm and death, be derived solely from custom and

experience. The same custom goes beyond the instances, from which it is

derived, and to which it perfectly corresponds; and influences his

ideas of such objects as are in some respect resembling, but fall not

precisely under the same rule. The circumstances of depth and descent

strike so strongly upon him, that their influence can-not be destroyed

by the contrary circumstances of support and solidity, which ought to

give him a perfect security. His imagination runs away with its object,

and excites a passion proportioned to it. That passion returns back

upon the imagination and inlivens the idea; which lively idea has a

new influence on the passion, and in its turn augments its force and

violence; and both his fancy and affections, thus mutually supporting

each other, cause the whole to have a very great influence upon him.

But why need we seek for other instances, while the present subject

of philosophical probabilities offers us so obvious an one, in the

opposition betwixt the judgment and imagination arising from these

effects of custom? According to my system, all reasonings are nothing

but the effects of custom; and custom has no influence, but by

inlivening the imagination, and giving us a strong conception of

any object. It may, therefore, be concluded, that our judgment and

imagination can never be contrary, and that custom cannot operate on

the latter faculty after such a manner, as to render it opposite to the

former. This difficulty we can remove after no other manner, than by

supposing the influence of general rules. We shall afterwards take[10]

notice of some general rules, by which we ought to regulate

our judgment concerning causes and effects; and these rules are formed

on the nature of our understanding, and on our experience of its

operations in the judgments we form concerning objects. By them we learn

to distinguish the accidental circumstances from the efficacious causes;

and when we find that an effect can be produced without the concurrence

of any particular circumstance, we conclude that that circumstance makes

not a part of the efficacious cause, however frequently conjoined with

it. But as this frequent conjunction necessity makes it have some effect

on the imagination, in spite of the opposite conclusion from general

rules, the opposition of these two principles produces a contrariety

in our thoughts, and causes us to ascribe the one inference to our

judgment, and the other to our imagination. The general rule is

attributed to our judgment; as being more extensive and constant. The

exception to the imagination, as being more capricious and uncertain.

[10] Sect. 15.

Thus our general rules are in a manner set in opposition to each other.

When an object appears, that resembles any cause in very considerable

circumstances, the imagination naturally carries us to a lively

conception of the usual effect, Though the object be different in the

most material and most efficacious circumstances from that cause. Here

is the first influence of general rules. But when we take a review of

this act of the mind, and compare it with the more general and authentic

operations of the understanding, we find it to be of an irregular

nature, and destructive of all the most established principles of

reasonings; which is the cause of our rejecting it. This is a second

influence of general rules, and implies the condemnation of the former.

Sometimes the one, sometimes the other prevails, according to the

disposition and character of the person. The vulgar are commonly guided

by the first, and wise men by the second. Mean while the sceptics may

here have the pleasure of observing a new and signal contradiction in

our reason, and of seeing all philosophy ready to be subverted by a

principle of human nature, and again saved by a new direction of

the very same principle. The following of general rules is a very

unphilosophical species of probability; and yet it is only by

following them that we can correct this, and all other unphilosophical

probabilities.

Since we have instances, where general rules operate on the imagination

even contrary to the judgment, we need not be surprized to see their

effects encrease, when conjoined with that latter faculty, and to

observe that they bestow on the ideas they present to us a force

superior to what attends any other. Every one knows, there is an

indirect manner of insinuating praise or blame, which is much less

shocking than the open flattery or censure of any person. However he may

communicate his sentiments by such secret insinuations, and make them

known with equal certainty as by the open discovery of them, it is

certain that their influence is not equally strong and powerful. One who

lashes me with concealed strokes of satire, moves not my indignation to

such a degree, as if he flatly told me I was a fool and coxcomb; though

I equally understand his meaning, as if he did. This difference is to be

attributed to the influence of general rules.

Whether a person openly, abuses me, or slyly intimates his contempt, in

neither case do I immediately perceive his sentiment or opinion; and it

is only by signs, that is, by its effects, I become sensible of it. The

only difference, then, betwixt these two cases consists in this, that

in the open discovery of his sentiments he makes use of signs, which are

general and universal; and in the secret intimation employs such as are

more singular and uncommon. The effect of this circumstance is, that the

imagination, in running from the present impression to the absent idea,

makes the transition with greater facility, and consequently conceives

the object with greater force, where the connexion is common and

universal, than where it is more rare and particular. Accordingly we

may observe, that the open declaration of our sentiments is called the

taking off the mask, as the secret intimation of our opinions is said

to be the veiling of them. The difference betwixt an idea produced by

a general connexion, and that arising from a particular one is here

compared to the difference betwixt an impression and an idea. This

difference in the imagination has a suitable effect on the passions; and

this effect is augmented by another circumstance. A secret intimation

of anger or contempt shews that we still have some consideration for

the person, and avoid the directly abusing him. This makes a concealed

satire less disagreeable; but still this depends on the same principle.

For if an idea were not more feeble, when only intimated, it would never

be esteemed a mark of greater respect to proceed in this method than in

the other.

Sometimes scurrility is less displeasing than delicate satire, because

it revenges us in a manner for the injury at the very time it is

committed, by affording us a just reason to blame and contemn the

person, who injures us. But this phænomenon likewise depends upon the

same principle. For why do we blame all gross and injurious language,

unless it be, because we esteem it contrary to good breeding and

humanity? And why is it contrary, unless it be more shocking than any

delicate satire? The rules of good breeding condemn whatever is openly

disobliging, and gives a sensible pain and confusion to those, with

whom we converse. After this is once established, abusive language is

universally blamed, and gives less pain upon account of its coarseness

and incivility, which render the person despicable, that employs it. It

becomes less disagreeable, merely because originally it is more so; and

it is more disagreeable, because it affords an inference by general and

common rules, that are palpable and undeniable.

To this explication of the different influence of open and concealed

flattery or satire, I shall add the consideration of another phenomenon,

which is analogous to it. There are many particulars in the point of

honour both of men and women, whose violations, when open and avowed,

the world never excuses, but which it is more apt to overlook, when the

appearances are saved, and the transgression is secret and concealed.

Even those, who know with equal certainty, that the fault is committed,

pardon it more easily, when the proofs seem in some measure oblique and

equivocal, than when they are direct and undeniable. The same idea is

presented in both cases, and, properly speaking, is equally assented

to by the judgment; and yet its influence is different, because of the

different manner, in which it is presented.

Now if we compare these two cases, of the open and concealed violations

of the laws of honour, we shall find, that the difference betwixt them

consists in this, that in the first ease the sign, from which we infer

the blameable action, is single, and suffices alone to be the

foundation of our reasoning and judgment; whereas in the latter the

signs are numerous, and decide little or nothing when alone and

unaccompanyed with many minute circumstances, which are almost

imperceptible. But it is certainly true, that any reasoning is always

the more convincing, the more single and united it is to the eye, and

the less exercise it gives to the imagination to collect all its parts,

and run from them to the correlative idea, which forms the conclusion.

The labour of the thought disturbs the regular progress of the

sentiments, as we shall observe presently.[11] The idea strikes not on

us with ouch vivacity; and consequently has no such influence on the

passion and imagination.

[11] Part IV. Sect. 1.

From the same principles we may account for those observations of the

CARDINAL DE RETZ, that there are many things, in which the world wishes

to be deceived; and that it more easily excuses a person in acting than

in talking contrary to the decorum of his profession and character. A

fault in words is commonly more open and distinct than one in actions,

which admit of many palliating excuses, and decide not so clearly

concerning the intention and views of the actor.

Thus it appears upon the whole, that every kind of opinion or judgment,

which amounts not to knowledge, is derived entirely from the force and

vivacity of the perception, and that these qualities constitute in the

mind, what we call the BELIEF Of the existence of any object. This force

and this vivacity are most conspicuous in the memory; and therefore our

confidence in the veracity of that faculty is the greatest imaginable,

and equals in many respects the assurance of a demonstration. The next

degree of these qualities is that derived from the relation of cause and

effect; and this too is very great, especially when the conjunction is

found by experience to be perfectly constant, and when the object,

which is present to us, exactly resembles those, of which we have had

experience. But below this degree of evidence there are many others,

which have an influence on the passions and imagination, proportioned to

that degree of force and vivacity, which they communicate to the ideas.

It is by habit we make the transition from cause to effect; and it is

from some present impression we borrow that vivacity, which we diffuse

over the correlative idea. But when we have not observed a sufficient

number of instances, to produce a strong habit; or when these instances

are contrary to each other; or when the resemblance is not exact; or

the present impression is faint and obscure; or the experience in some

measure obliterated from the memory; or the connexion dependent on a

long chain of objects; or the inference derived from general rules, and

yet not conformable to them: In all these cases the evidence diminishes

by the diminution of the force and intenseness of the idea. This

therefore is the nature of the judgment and probability.

What principally gives authority to this system is, beside the undoubted

arguments, upon which each part is founded, the agreement of these

parts, and the necessity of one to explain another. The belief, which

attends our memory, is of the same nature with that, which is derived

from our judgments: Nor is there any difference betwixt that judgment,

which is derived from a constant and uniform connexion of causes and

effects, and that which depends upon an interrupted and uncertain. It is

indeed evident, that in all determinations, where the mind decides from

contrary experiments, it is first divided within itself, and has an

inclination to either side in proportion to the number of experiments

we have seen and remember. This contest is at last determined to the

advantage of that side, where we observe a superior number of these

experiments; but still with a diminution of force in the evidence

correspondent to the number of the opposite experiments. Each

possibility, of which the probability is composed, operates separately

upon the imagination; and it is the larger collection of possibilities,

which at last prevails, and that with a force proportionable to its

superiority. All these phenomena lead directly to the precedent system;

nor will it ever be possible upon any other principles to give a

satisfactory and consistent explication of them. Without considering

these judgments as the effects of custom on the imagination, we shall

lose ourselves in perpetual contradiction and absurdity.

SECT. XIV. OF THE IDEA OF NECESSARY CONNEXION.

Having thus explained the manner, in which we reason beyond our

immediate impressions, and conclude that such particular causes must

have such particular effects; we must now return upon our footsteps to

examine that question, which[12] first occured to us, and which we

dropt in our way, viz. What is our idea of necessity, when we say that

two objects are necessarily connected together. Upon this head I repeat

what I have often had occasion to observe, that as we have no idea,

that is not derived from an impression, we must find some impression,

that gives rise to this idea of necessity, if we assert we have really

such an idea. In order to this I consider, in what objects necessity is

commonly supposed to lie; and finding that it is always ascribed to

causes and effects, I turn my eye to two objects supposed to be placed

in that relation; and examine them in all the situations, of which they

are susceptible. I immediately perceive, that they are contiguous in

time and place, and that the object we call cause precedes the other we

call effect. In no one instance can I go any farther, nor is it

possible for me to discover any third relation betwixt these objects. I

therefore enlarge my view to comprehend several instances; where I find

like objects always existing in like relations of contiguity and

succession. At first sight this seems to serve but little to my

purpose. The reflection on several instances only repeats the same

objects; and therefore can never give rise to a new idea. But upon

farther enquiry I find, that the repetition is not in every particular

the same, but produces a new impression, and by that means the idea,

which I at present examine. For after a frequent repetition, I find,

that upon the appearance of one of the objects, the mind is determined

by custom to consider its usual attendant, and to consider it in a

stronger light upon account of its relation to the first object. It is

this impression, then, or determination, which affords me the idea of

necessity.

[12] Sect. 2.

I doubt not but these consequences will at first sight be received

without difficulty, as being evident deductions from principles, which

we have already established, and which we have often employed in our

reasonings. This evidence both in the first principles, and in the

deductions, may seduce us unwarily into the conclusion, and make us

imagine it contains nothing extraordinary, nor worthy of our curiosity.

But though such an inadvertence may facilitate the reception of this

reasoning, it will make it be the more easily forgot; for which reason

I think it proper to give warning, that I have just now examined one of

the most sublime questions in philosophy, viz. that concerning the power

and efficacy of causes; where all the sciences seem so much interested.

Such a warning will naturally rouze up the attention of the reader, and

make him desire a more full account of my doctrine, as well as of the

arguments, on which it is founded. This request is so reasonable, that

I cannot refuse complying with it; especially as I am hopeful that these

principles, the more they are examined, will acquire the more force and

evidence.

There is no question, which on account of its importance, as well as

difficulty, has caused more disputes both among antient and modern

philosophers, than this concerning the efficacy of causes, or that

quality which makes them be followed by their effects. But before they

entered upon these disputes, methinks it would not have been improper to

have examined what idea we have of that efficacy, which is the subject

of the controversy. This is what I find principally wanting in their

reasonings, and what I shall here endeavour to supply.

I begin with observing that the terms of EFFICACY, AGENCY, POWER, FORCE,

ENERGY, NECESSITY, CONNEXION, and PRODUCTIVE QUALITY, are all nearly

synonymous; and therefore it is an absurdity to employ any of them in

defining the rest. By this observation we reject at once all the vulgar

definitions, which philosophers have given of power and efficacy; and

instead of searching for the idea in these definitions, must look for

it in the impressions, from which it is originally derived. If it be a

compound idea, it must arise from compound impressions. If simple, from

simple impressions.

I believe the most general and most popular explication of this matter,

is to say,[13] that finding from experience, that there are several new

productions in matter, such as the motions and variations of body, and

concluding that there must somewhere be a power capable of producing

them, we arrive at last by this reasoning at the idea of power and

efficacy. But to be convinced that this explication is more popular

than philosophical, we need but reflect on two very obvious principles.

First, that reason alone can never give rise to any original idea, and

secondly, that reason, as distinguished from experience, can never make

us conclude, that a cause or productive quality is absolutely requisite

to every beginning of existence. Both these considerations have been

sufficiently explained: and therefore shall not at present be any

farther insisted on.

[13] See Mr. Locke, chapter of power.

I shall only infer from them, that since reason can never give rise to

the idea of efficacy, that idea must be derived from experience, and

from some particular instances of this efficacy, which make their

passage into the mind by the common channels of sensation or reflection.

Ideas always represent their objects or impressions; and vice versa,

there are some objects necessary to give rise to every idea. If we

pretend, therefore, to have any just idea of this efficacy, we must

produce some instance, wherein the efficacy is plainly discoverable to

the mind, and its operations obvious to our consciousness or sensation.

By the refusal of this, we acknowledge, that the idea is impossible and

imaginary, since the principle of innate ideas, which alone can save

us from this dilemma, has been already refuted, and is now almost

universally rejected in the learned world. Our present business,

then, must be to find some natural production, where the operation and

efficacy of a cause can be clearly conceived and comprehended by the

mind, without any danger of obscurity or mistake.

In this research we meet with very little encouragement from that

prodigious diversity, which is found in the opinions of those

philosophers, who have pretended to explain the secret force and energy

of causes.[14] There are some, who maintain, that bodies operate by

their substantial form; others, by their accidents or qualities;

several, by their matter and form; some, by their form and accidents;

others, by certain virtues and faculties distinct from all this. All

these sentiments again are mixed and varyed in a thousand different

ways; and form a strong presumption, that none of them have any

solidity or evidence, and that the supposition of an efficacy in any of

the known qualities of matter is entirely without foundation. This

presumption must encrease upon us, when we consider, that these

principles of substantial forms, and accidents, and faculties, are not

in reality any of the known properties of bodies, but are perfectly

unintelligible and inexplicable. For it is evident philosophers would

never have had recourse to such obscure and uncertain principles, had

they met with any satisfaction in such as are clear and intelligible;

especially in such an affair as this, which must be an object of the

simplest understanding, if not of the senses. Upon the whole, we may

conclude, that it is impossible in any one instance to shew the

principle, in which the force and agency of a cause is placed; and that

the most refined and most vulgar understandings are equally at a loss

in this particular. If any one think proper to refute this assertion,

he need not put himself to the trouble of inventing any long

reasonings: but may at once shew us an instance of a cause, where we

discover the power or operating principle. This defiance we are obliged

frequently to make use of, as being almost the only means of proving a

negative in philosophy.

[14] See Father Malbranche, Book vi. Part 2, chap. 3. And the

illustrations upon it.

The small success, which has been met with in all the attempts to fix

this power, has at last obliged philosophers to conclude, that the

ultimate force and efficacy of nature is perfectly unknown to us,

and that it is in vain we search for it in all the known qualities of

matter. In this opinion they are almost unanimous; and it is only in the

inference they draw from it, that they discover any difference in their

sentiments. For some of them, as the CARTESIANS in particular, having

established it as a principle, that we are perfectly acquainted with the

essence of matter, have very naturally inferred, that it is endowed with

no efficacy, and that it is impossible for it of itself to communicate

motion, or produce any of those effects, which we ascribe to it. As the

essence of matter consists in extension, and as extension implies not

actual motion, but only mobility; they conclude, that the energy, which

produces the motion, cannot lie in the extension.

This conclusion leads them into another, which they regard as perfectly

unavoidable. Matter, say they, is in itself entirely unactive, and

deprived of any power, by which it may produce, or continue, or

communicate motion: But since these effects are evident to our senses,

and since the power, that produces them, must be placed somewhere, it

must lie in the DEITY, or that divine being, who contains in his nature

all excellency and perfection. It is the deity, therefore, who is the

prime mover of the universe, and who not only first created matter, and

gave it it's original impulse, but likewise by a continued exertion of

omnipotence, supports its existence, and successively bestows on it

all those motions, and configurations, and qualities, with which it is

endowed.

This opinion is certainly very curious, and well worth our attention;

but it will appear superfluous to examine it in this place, if we

reflect a moment on our present purpose in taking notice of it. We

have established it as a principle, that as all ideas are derived from

impressions, or some precedent perceptions, it is impossible we can have

any idea of power and efficacy, unless some instances can be produced,

wherein this power is perceived to exert itself. Now, as these instances

can never be discovered in body, the Cartesians, proceeding upon their

principle of innate ideas, have had recourse to a supreme spirit or

deity, whom they consider as the only active being in the universe, and

as the immediate cause of every alteration in matter. But the principle

of innate ideas being allowed to be false, it follows, that the

supposition of a deity can serve us in no stead, in accounting for that

idea of agency, which we search for in vain in all the objects, which

are presented to our senses, or which we are internally conscious of in

our own minds. For if every idea be derived from an impression, the idea

of a deity proceeds from the same origin; and if no impression, either

of sensation or reflection, implies any force or efficacy, it is equally

impossible to discover or even imagine any such active principle in the

deity. Since these philosophers, therefore, have concluded, that

matter cannot be endowed with any efficacious principle, because it

is impossible to discover in it such a principle; the same course of

reasoning should determine them to exclude it from the supreme being. Or

if they esteem that opinion absurd and impious, as it really is, I shall

tell them how they may avoid it; and that is, by concluding from the

very first, that they have no adequate idea of power or efficacy in

any object; since neither in body nor spirit, neither in superior nor

inferior natures, are they able to discover one single instance of it.

The same conclusion is unavoidable upon the hypothesis of those, who

maintain the efficacy of second causes, and attribute a derivative, but

a real power and energy to matter. For as they confess, that this energy

lies not in any of the known qualities of matter, the difficulty still

remains concerning the origin of its idea. If we have really an idea

of power, we may attribute power to an unknown quality: But as it is

impossible, that that idea can be derived from such a quality, and as

there is nothing in known qualities, which can produce it; it follows

that we deceive ourselves, when we imagine we are possest of any idea

of this kind, after the manner we commonly understand it. All ideas are

derived from, and represent impressions. We never have any impression,

that contains any power or efficacy. We never therefore have any idea of

power.

Some have asserted, that we feel an energy, or power, in our own mind;

and that having in this manner acquired the idea of power, we transfer

that quality to matter, where we are not able immediately to discover

it. The motions of our body, and the thoughts and sentiments of our

mind, (say they) obey the will; nor do we seek any farther to acquire

a just notion of force or power. But to convince us how fallacious this

reasoning is, we need only consider, that the will being here considered

as a cause, has no more a discoverable connexion with its effects, than

any material cause has with its proper effect. So far from perceiving

the connexion betwixt an act of volition, and a motion of the body;

it is allowed that no effect is more inexplicable from the powers and

essence of thought and matter. Nor is the empire of the will over

our mind more intelligible. The effect is there distinguishable

and separable from the cause, and could not be foreseen without the

experience of their constant conjunction. We have command over our mind

to a certain degree, but beyond that, lose all empire over it: And it is

evidently impossible to fix any precise bounds to our authority, where

we consult not experience. In short, the actions of the mind are, in

this respect, the same with those of matter. We perceive only their

constant conjunction; nor can we ever reason beyond it. No internal

impression has an apparent energy, more than external objects have.

Since, therefore, matter is confessed by philosophers to operate by

an unknown force, we should in vain hope to attain an idea of force by

consulting our own minds.[15]

[15] The same imperfection attends our ideas of the Deity; but this

can have no effect either on religion or morals. The order of the

universe proves an omnipotent mind; that is, a mind whose will is

CONSTANTLY ATTENDED with the obedience of every creature and being.

Nothing more is requisite to give a foundation to all the articles

of religion, nor is It necessary we shoud form a distinct idea of

the force and energy of the supreme Being.

It has been established as a certain principle, that general or abstract

ideas are nothing but individual ones taken in a certain light, and

that, in reflecting on any object, it is as impossible to exclude from

our thought all particular degrees of quantity and quality as from the

real nature of things. If we be possest, therefore, of any idea of power

in general, we must also be able to conceive some particular species

of it; and as power cannot subsist alone, but is always regarded as an

attribute of some being or existence, we must be able to place this

power in some particular being, and conceive that being as endowed with

a real force and energy, by which such a particular effect necessarily

results from its operation. We must distinctly and particularly conceive

the connexion betwixt the cause and effect, and be able to pronounce,

from a simple view of the one, that it must be followed or preceded by

the other. This is the true manner of conceiving a particular power in

a particular body: and a general idea being impossible without an

individual; where the latter is impossible, it is certain the former

can never exist. Now nothing is more evident, than that the human mind

cannot form such an idea of two objects, as to conceive any connexion

betwixt them, or comprehend distinctly that power or efficacy, by which

they are united. Such a connexion would amount to a demonstration, and

would imply the absolute impossibility for the one object not to follow,

or to be conceived not to follow upon the other: Which kind of connexion

has already been rejected in all cases. If any one is of a contrary

opinion, and thinks he has attained a notion of power in any particular

object, I desire he may point out to me that object. But till I meet

with such-a-one, which I despair of, I cannot forbear concluding, that

since we can never distinctly conceive how any particular power can

possibly reside in any particular object, we deceive ourselves in

imagining we can form any such general idea.

Thus upon the whole we may infer, that when we talk of any being,

whether of a superior or inferior nature, as endowed with a power

or force, proportioned to any effect; when we speak of a necessary

connexion betwixt objects, and suppose, that this connexion depends upon

an efficacy or energy, with which any of these objects are endowed; in

all these expressions, so applied, we have really no distinct meaning,

and make use only of common words, without any clear and determinate

ideas. But as it is more probable, that these expressions do here lose

their true meaning by being wrong applied, than that they never have

any meaning; it will be proper to bestow another consideration on this

subject, to see if possibly we can discover the nature and origin of

those ideas, we annex to them.

Suppose two objects to be presented to us, of which the one is the

cause and the other the effect; it is plain, that from the simple

consideration of one, or both these objects we never shall perceive the

tie by which they are united, or be able certainly to pronounce, that

there is a connexion betwixt them. It is not, therefore, from any one

instance, that we arrive at the idea of cause and effect, of a necessary

connexion of power, of force, of energy, and of efficacy. Did we never

see any but particular conjunctions of objects, entirely different from

each other, we should never be able to form any such ideas.

But again; suppose we observe several instances, in which the same

objects are always conjoined together, we immediately conceive a

connexion betwixt them, and begin to draw an inference from one

to another. This multiplicity of resembling instances, therefore,

constitutes the very essence of power or connexion, and is the source

from which the idea of it arises. In order, then, to understand the idea

of power, we must consider that multiplicity; nor do I ask more to give

a solution of that difficulty, which has so long perplexed us. For thus

I reason. The repetition of perfectly similar instances can never alone

give rise to an original idea, different from what is to be found in any

particular instance, as has been observed, and as evidently follows from

our fundamental principle, that all ideas are copyed from impressions.

Since therefore the idea of power is a new original idea, not to be

found in any one instance, and which yet arises from the repetition of

several instances, it follows, that the repetition alone has not that

effect, but must either discover or produce something new, which is the

source of that idea. Did the repetition neither discover nor produce

anything new, our ideas might be multiplyed by it, but would not

be enlarged above what they are upon the observation of one single

instance. Every enlargement, therefore, (such as the idea of power or

connexion) which arises from the multiplicity of similar instances,

is copyed from some effects of the multiplicity, and will be perfectly

understood by understanding these effects. Wherever we find anything new

to be discovered or produced by the repetition, there we must place the

power, and must never look for it in any other object.

But it is evident, in the first place, that the repetition of like

objects in like relations of succession and contiguity discovers

nothing new in any one of them: since we can draw no inference from it,

nor make it a subject either of our demonstrative or probable

reasonings;[16] as has been already proved. Nay suppose we could draw

an inference, it would be of no consequence in the present case; since

no kind of reasoning can give rise to a new idea, such as this of power

is; but wherever we reason, we must antecedently be possest of clear

ideas, which may be the objects of our reasoning. The conception always

precedes the understanding; and where the one is obscure, the other is

uncertain; where the one fails, the other must fail also.

[16] Sect. 6.

Secondly, It is certain that this repetition of similar objects in

similar situations produces nothing new either in these objects, or

in any external body. For it will readily be allowed, that the several

instances we have of the conjunction of resembling causes and effects

are in themselves entirely independent, and that the communication

of motion, which I see result at present from the shock of two

billiard-balls, is totally distinct from that which I saw result from

such an impulse a twelve-month ago. These impulses have no influence

on each other. They are entirely divided by time and place; and the one

might have existed and communicated motion, though the other never had

been in being.

There is, then, nothing new either discovered or produced in any objects

by their constant conjunction, and by the uninterrupted resemblance

of their relations of succession and contiguity. But it is from this

resemblance, that the ideas of necessity, of power, and of efficacy, are

derived. These ideas, therefore, represent not anything, that does or

can belong to the objects, which are constantly conjoined. This is

an argument, which, in every view we can examine it, will be found

perfectly unanswerable. Similar instances are still the first source

of our idea of power or necessity; at the same time that they have no

influence by their similarity either on each other, or on any external

object. We must, therefore, turn ourselves to some other quarter to seek

the origin of that idea.

Though the several resembling instances, which give rise to the idea of

power, have no influence on each other, and can never produce any new

quality in the object, which can be the model of that idea, yet the

observation of this resemblance produces a new impression in the mind,

which is its real model. For after we have observed the resemblance in

a sufficient number of instances, we immediately feel a determination of

the mind to pass from one object to its usual attendant, and to conceive

it in a stronger light upon account of that relation. This determination

is the only effect of the resemblance; and therefore must be the same

with power or efficacy, whose idea is derived from the resemblance. The

several instances of resembling conjunctions lead us into the notion of

power and necessity. These instances are in themselves totally distinct

from each other, and have no union but in the mind, which observes

them, and collects their ideas. Necessity, then, is the effect of this

observation, and is nothing but an internal impression of the mind,

or a determination to carry our thoughts from one object to another.

Without considering it in this view, we can never arrive at the most

distant notion of it, or be able to attribute it either to external or

internal objects, to spirit or body, to causes or effects.

The necessary connexion betwixt causes and effects is the foundation of

our inference from one to the other. The foundation of our inference is

the transition arising from the accustomed union. These are, therefore,

the same.

The idea of necessity arises from some impression. There is no

impression conveyed by our senses, which can give rise to that idea. It

must, therefore, be derived from some internal impression, or impression

of reflection. There is no internal impression, which has any relation

to the present business, but that propensity, which custom produces, to

pass from an object to the idea of its usual attendant. This therefore

is the essence of necessity. Upon the whole, necessity is something,

that exists in the mind, not in objects; nor is it possible for us ever

to form the most distant idea of it, considered as a quality in bodies.

Either we have no idea of necessity, or necessity is nothing but that

determination of the thought to pass from causes to effects, and from

effects to causes, according to their experienced union.

Thus as the necessity, which makes two times two equal to four, or three

angles of a triangle equal to two right ones, lies only in the act of

the understanding, by which we consider and compare these ideas; in like

manner the necessity or power, which unites causes and effects, lies

in the determination of the mind to pass from the one to the other. The

efficacy or energy of causes is neither placed in the causes themselves,

nor in the deity, nor in the concurrence of these two principles; but

belongs entirely to the soul, which considers the union of two or more

objects in all past instances. It is here that the real power of causes

is placed along with their connexion and necessity.

I am sensible, that of all the paradoxes, which I, have had, or shall

hereafter have occasion to advance in the course of this treatise, the

present one is the most violent, and that it is merely by dint of solid

proof and reasoning I can ever hope it will have admission, and overcome

the inveterate prejudices of mankind. Before we are reconciled to this

doctrine, how often must we repeat to ourselves, that the simple view of

any two objects or actions, however related, can never give us any idea,

of power, or of a connexion betwixt them: that this idea arises from

the repetition of their union: that the repetition neither discovers nor

causes any thing in the objects, but has an influence only on the mind,

by that customary transition it produces: that this customary transition

is, therefore, the same with the power and necessity; which are

consequently qualities of perceptions, not of objects, and are

internally felt by the soul, and not perceivd externally in bodies?

There is commonly an astonishment attending every thing extraordinary;

and this astonishment changes immediately into the highest degree

of esteem or contempt, according as we approve or disapprove of the

subject. I am much afraid, that though the foregoing reasoning appears

to me the shortest and most decisive imaginable; yet with the generality

of readers the biass of the mind will prevail, and give them a prejudice

against the present doctrine.

This contrary biass is easily accounted for. It is a common

observation, that the mind has a great propensity to spread itself on

external objects, and to conjoin with them any internal impressions,

which they occasion, and which always make their appearance at the same

time that these objects discover themselves to the senses. Thus as

certain sounds and smells are always found to attend certain visible

objects, we naturally imagine a conjunction, even in place, betwixt the

objects and qualities, though the qualities be of such a nature as to

admit of no such conjunction, and really exist no where. But of this

more fully hereafter.[17] Mean while it is sufficient to observe, that

the same propensity is the reason, why we suppose necessity and power

to lie in the objects we consider, not in our mind that considers them;

notwithstanding it is not possible for us to form the most distant idea

of that quality, when it is not taken for the determination of the

mind, to pass from the idea of an object to that of its usual

attendant.

[17] Part IV, Sect. 5.

But though this be the only reasonable account we can give of necessity,

the contrary notion if; so riveted in the mind from the principles

above-mentioned, that I doubt not but my sentiments will be treated by

many as extravagant and ridiculous. What! the efficacy of causes lie

in the determination of the mind! As if causes did not operate entirely

independent of the mind, and would not continue their operation,

even though there was no mind existent to contemplate them, or reason

concerning them. Thought may well depend on causes for its operation,

but not causes on thought. This is to reverse the order of nature, and

make that secondary, which is really primary, To every operation there

is a power proportioned; and this power must be placed on the body, that

operates. If we remove the power from one cause, we must ascribe it to

another: But to remove it from all causes, and bestow it on a being,

that is no ways related to the cause or effect, but by perceiving them,

is a gross absurdity, and contrary to the most certain principles of

human reason.

I can only reply to all these arguments, that the case is here much the

same, as if a blind man should pretend to find a great many absurdities

in the supposition, that the colour of scarlet is not the same with the

sound of a trumpet, nor light the same with solidity. If we have really

no idea of a power or efficacy in any object, or of any real connexion

betwixt causes and effects, it will be to little purpose to prove, that

an efficacy is necessary in all operations. We do not understand our own

meaning in talking so, but ignorantly confound ideas, which are entirely

distinct from each other. I am, indeed, ready to allow, that there may

be several qualities both in material and immaterial objects, with which

we are utterly unacquainted; and if we please to call these POWER or

EFFICACY, it will be of little consequence to the world. But when,

instead of meaning these unknown qualities, we make the terms of power

and efficacy signify something, of which we have a clear idea, and which

is incompatible with those objects, to which we apply it, obscurity

and error begin then to take place, and we are led astray by a false

philosophy. This is the case, when we transfer the determination of the

thought to external objects, and suppose any real intelligible connexion

betwixt them; that being a quality, which can only belong to the mind

that considers them.

As to what may be said, that the operations of nature are independent

of our thought and reasoning, I allow it; and accordingly have observed,

that objects bear to each other the relations of contiguity and

succession: that like objects may be observed in several instances to

have like relations; and that all this is independent of, and antecedent

to the operations of the understanding. But if we go any farther, and

ascribe a power or necessary connexion to these objects; this is what

we can never observe in them, but must draw the idea of it from what we

feel internally in contemplating them. And this I carry so far, that I

am ready to convert my present reasoning into an instance of it, by a

subtility, which it will not be difficult to comprehend.

When any object is presented to us, it immediately conveys to the mind

a lively idea of that object, which is usually found to attend it; and

this determination of the mind forms the necessary connexion of these

objects. But when we change the point of view, from the objects to the

perceptions; in that case the impression is to be considered as the

cause, and the lively idea as the effect; and their necessary connexion

is that new determination, which we feel to pass from the idea of the

one to that of the other. The uniting principle among our internal

perceptions is as unintelligible as that among external objects, and

is not known to us any other way than by experience. Now the nature

and effects of experience have been already sufficiently examined and

explained. It never gives us any insight into the internal structure or

operating principle of objects, but only accustoms the mind to pass from

one to another.

It is now time to collect all the different parts of this reasoning,

and by joining them together form an exact definition of the relation of

cause and effect, which makes the subject of the present enquiry. This

order would not have been excusable, of first examining our inference

from the relation before we had explained the relation itself, had it

been possible to proceed in a different method. But as the nature of the

relation depends so much on that of the inference, we have been obliged

to advance in this seemingly preposterous manner, and make use of terms

before we were able exactly to define them, or fix their meaning. We

shall now correct this fault by giving a precise definition of cause and

effect.

There may two definitions be given of this relation, which are only

different, by their presenting a different view of the same object,

and making us consider it either as a philosophical or as a natural

relation; either as a comparison of two ideas, or as an association

betwixt them. We may define a CAUSE to be An object precedent and

contiguous to another, and where all the objects resembling the former

are placed in like relations of precedency and contiguity to those

objects that resemble the latter. I If this definition be esteemed

defective, because drawn from objects foreign to the cause, we may

substitute this other definition in its place, viz. A CAUSE is an object

precedent and contiguous to another, and so united with it, that the

idea, of the one determines the mind to form the idea of the other, and

the impression of the one to form a more lively idea of the other. 2

should this definition also be rejected for the same reason, I know no

other remedy, than that the persons, who express this delicacy, should

substitute a juster definition in its place. But for my part I must own

my incapacity for such an undertaking. When I examine with the utmost

accuracy those objects, which are commonly denominated causes and

effects, I find, in considering a single instance, that the one object

is precedent and contiguous to the other; and in inlarging my view

to consider several instances, I find only, that like objects are

constantly placed in like relations of succession and contiguity. Again,

when I consider the influence of this constant conjunction, I perceive,

that such a relation can never be an object of reasoning, and can never

operate upon the mind, but by means of custom, which determines the

imagination to make a transition from the idea of one object to that

of its usual attendant, and from the impression of one to a more lively

idea of the other. However extraordinary these sentiments may appear,

I think it fruitless to trouble myself with any farther enquiry or

reasoning upon the subject, but shall repose myself on them as on

established maxims.

It will only be proper, before we leave this subject, to draw some

corrollaries from it, by which we may remove several prejudices and

popular errors, that have very much prevailed in philosophy. First, We

may learn from the foregoing, doctrine, that all causes are of the

same kind, and that in particular there is no foundation for that

distinction, which we sometimes make betwixt efficient causes and causes

sine qua non; or betwixt efficient causes, and formal, and material, and

exemplary, and final causes. For as our idea of efficiency is derived

from the constant conjunction of two objects, wherever this is observed,

the cause is efficient; and where it is not, there can never be a cause

of any kind. For the same reason we must reject the distinction betwixt

cause and occasion, when supposed to signify any thing essentially

different from each other. If constant conjunction be implyed in what we

call occasion, it is a real cause. If not, it is no relation at all, and

cannot give rise to any argument or reasoning.

Secondly, The same course of reasoning will make us conclude, that there

is but one kind of necessity, as there is but one kind of cause, and

that the common distinction betwixt moral and physical necessity

is without any foundation in nature. This clearly appears from the

precedent explication of necessity. It is the constant conjunction of

objects, along with the determination of the mind, which constitutes

a physical necessity: And the removal of these is the same thing with

chance. As objects must either be conjoined or not, and as the mind must

either be determined or not to pass from one object to another, it

is impossible to admit of any medium betwixt chance and an absolute

necessity. In weakening this conjunction and determination you do not

change the nature of the necessity; since even in the operation of

bodies, these have different degrees of constancy and force, without

producing a different species of that relation.

The distinction, which we often make betwixt POWER and the EXERCISE of

it, is equally without foundation.

Thirdly, We may now be able fully to overcome all that repugnance, which

it is so natural for us to entertain against the foregoing reasoning,

by which we endeavoured to prove, that the necessity of a cause to

every beginning of existence is not founded on any arguments either

demonstrative or intuitive. Such an opinion will not appear strange

after the foregoing definitions. If we define a cause to be an

object precedent and contiguous to another, and where all the objects

resembling the farmer are placed in a like relation of priority and

contiguity to those objects, that resemble the latter; we may easily

conceive, that there is no absolute nor metaphysical necessity, that

every beginning of existence should be attended with such an object. If

we define a cause to be, AN OBJECT PRECEDENT AND CONTIGUOUS TO ANOTHER,

AND SO UNITED WITH IT IN THE IMAGINATION, THAT THE IDEA OF THE ONE

DETERMINES THE MIND TO FORM THE IDEA OF THE OTHER, AND THE IMPRESSION

OF THE ONE TO FORM A MORE LIVELY IDEA OF THE OTHER; we shall make still

less difficulty of assenting to this opinion. Such an influence on the

mind is in itself perfectly extraordinary and incomprehensible; nor can

we be certain of its reality, but from experience and observation.

I shall add as a fourth corrollary that we can never have reason to

believe that any object exists, of which we cannot form an idea. For as

all our reasonings concerning existence are derived from causation,

and as all our reasonings concerning causation are derived from

the experienced conjunction of objects, not from any reasoning or

reflection, the same experience must give us a notion of these objects,

and must remove all mystery from our conclusions. This is so evident,

that it would scarce have merited our attention, were it not to obviate

certain objections of this kind, which might arise against the following

reasonings concerning matter and substance. I need not observe, that

a full knowledge of the object is not requisite, but only of those

qualities of it, which we believe to exist.

SECT. XV. RULES BY WHICH TO JUDGE OF CAUSES AND EFFECTS.

According to the precedent doctrine, there are no objects which by the

mere survey, without consulting experience, we can determine to be the

causes of any other; and no objects, which we can certainly determine

in the same manner not to be the causes. Any thing may produce any

thing. Creation, annihilation, motion, reason, volition; all these may

arise from one another, or from any other object we can imagine. Nor

will this appear strange, if we compare two principles explained above,

THAT THE CONSTANT CONJUNCTION OF OBJECTS DETERMINES THEIR CAUSATION,

AND[18] THAT, PROPERTY SPEAKING, NO OBJECTS ARE CONTRARY TO EACH OTHER

BUT EXISTENCE AND NON-EXISTENCE. Where objects are not contrary,

nothing hinders them from having that constant conjunction, on which

the relation of cause and effect totally depends.

[18] Part I. Sect. 5.

Since therefore it is possible for all objects to become causes or

effects to each other, it may be proper to fix some general rules, by

which we may know when they really are so.

(1) The cause and effect must be contiguous in space and time.

(2) The cause must be prior to the effect.

(3) There must be a constant union betwixt the cause and effect. It is

chiefly this quality, that constitutes the relation.

(4) The same cause always produces the same effect, and the same effect

never arises but from the same cause. This principle we derive from

experience, and is the source of most of our philosophical reasonings.

For when by any clear experiment we have discovered the causes or

effects of any phænomenon, we immediately extend our observation to

every phenomenon of the same kind, without waiting for that constant

repetition, from which the first idea of this relation is derived.

(5) There is another principle, which hangs upon this, viz. that where

several different objects produce the same effect, it must be by means

of some quality, which we discover to be common amongst them. For as

like effects imply like causes, we must always ascribe the causation to

the circumstance, wherein we discover the resemblance.

(6) The following principle is founded on the same reason. The

difference in the effects of two resembling objects must proceed from

that particular, in which they differ. For as like causes always

produce like effects, when in any instance we find our expectation to be

disappointed, we must conclude that this irregularity proceeds from some

difference in the causes.

(7) When any object encreases or diminishes with the encrease or

diminution of its cause, it is to be regarded as a compounded effect,

derived from the union of the several different effects, which arise

from the several different parts of the cause. The absence or presence

of one part of the cause is here supposed to be always attended with

the absence or presence of a proportionable part of the effect. This

constant conjunction sufficiently proves, that the one part is the cause

of the other. We must, however, beware not to draw such a conclusion

from a few experiments. A certain degree of heat gives pleasure; if you

diminish that heat, the pleasure diminishes; but it does not follow,

that if you augment it beyond a certain degree, the pleasure will

likewise augment; for we find that it degenerates into pain.

(8) The eighth and last rule I shall take notice of is, that an object,

which exists for any time in its full perfection without any effect, is

not the sole cause of that effect, but requires to be assisted by some

other principle, which may forward its influence and operation. For as

like effects necessarily follow from like causes, and in a contiguous

time and place, their separation for a moment shews, that these causes

are not compleat ones.

Here is all the LOGIC I think proper to employ in my reasoning; and

perhaps even this was not very necessary, but might have been supplyd by

the natural principles of our understanding. Our scholastic head-pieces

and logicians shew no such superiority above the mere vulgar in their

reason and ability, as to give us any inclination to imitate them in

delivering a long system of rules and precepts to direct our judgment,

in philosophy. All the rules of this nature are very easy in their

invention, but extremely difficult in their application; and even

experimental philosophy, which seems the most natural and simple of any,

requires the utmost stretch of human judgment. There is no phænomenon

in nature, but what is compounded and modifyd by so many different

circumstances, that in order to arrive at the decisive point, we

must carefully separate whatever is superfluous, and enquire by new

experiments, if every particular circumstance of the first experiment

was essential to it. These new experiments are liable to a discussion

of the same kind; so that the utmost constancy is requird to make us

persevere in our enquiry, and the utmost sagacity to choose the right

way among so many that present themselves. If this be the case even

in natural philosophy, how much more in moral, where there is a much

greater complication of circumstances, and where those views and

sentiments, which are essential to any action of the mind, are so

implicit and obscure, that they often escape our strictest attention,

and are not only unaccountable in their causes, but even unknown in

their existence? I am much afraid lest the small success I meet with

in my enquiries will make this observation bear the air of an apology

rather than of boasting.

If any thing can give me security in this particular, it will be the

enlarging of the sphere of my experiments as much as possible; for which

reason it may be proper in this place to examine the reasoning faculty

of brutes, as well as that of human creatures.

SECT. XVI OF THE REASON OF ANIMALS

Next to the ridicule of denying an evident truth, is that of taking much

pains to defend it; and no truth appears to me more evident, than that

beasts are endowd with thought and reason as well as men. The arguments

are in this case so obvious, that they never escape the most stupid and

ignorant.

We are conscious, that we ourselves, in adapting means to ends, are

guided by reason and design, and that it is not ignorantly nor casually

we perform those actions, which tend to self-preservation, to the

obtaining pleasure, and avoiding pain. When therefore we see other

creatures, in millions of instances, perform like actions, and direct

them to the ends, all our principles of reason and probability carry us

with an invincible force to believe the existence of a like cause. It is

needless in my opinion to illustrate this argument by the enumeration

of particulars. The smallest attention will supply us with more than are

requisite. The resemblance betwixt the actions of animals and those

of men is so entire in this respect, that the very first action of

the first animal we shall please to pitch on, will afford us an

incontestable argument for the present doctrine.

This doctrine is as useful as it is obvious, and furnishes us with a

kind of touchstone, by which we may try every system in this species

of philosophy. It is from the resemblance of the external actions of

animals to those we ourselves perform, that we judge their internal

likewise to resemble ours; and the same principle of reasoning, carryd

one step farther, will make us conclude that since our internal actions

resemble each other, the causes, from which they are derivd, must also

be resembling. When any hypothesis, therefore, is advancd to explain a

mental operation, which is common to men and beasts, we must apply the

same hypothesis to both; and as every true hypothesis will abide this

trial, so I may venture to affirm, that no false one will ever be able

to endure it. The common defect of those systems, which philosophers

have employd to account for the actions of the mind, is, that they

suppose such a subtility and refinement of thought, as not only exceeds

the capacity of mere animals, but even of children and the common people

in our own species; who are notwithstanding susceptible of the same

emotions and affections as persons of the most accomplishd genius and

understanding. Such a subtility is a dear proof of the falshood, as the

contrary simplicity of the truth, of any system.

Let us therefore put our present system concerning the nature of the

understanding to this decisive trial, and see whether it will equally

account for the reasonings of beasts as for these of the human species.

Here we must make a distinction betwixt those actions of animals, which

are of a vulgar nature, and seem to be on a level with their common

capacities, and those more extraordinary instances of sagacity, which

they sometimes discover for their own preservation, and the propagation

of their species. A dog, that avoids fire and precipices, that shuns

strangers, and caresses his master, affords us an instance of the first

kind. A bird, that chooses with such care and nicety the place and

materials of her nest, and sits upon her eggs for a due time, and in

suitable season, with all the precaution that a chymist is capable of in

the most delicate projection, furnishes us with a lively instance of the

second.

As to the former actions, I assert they proceed from a reasoning, that

is not in itself different, nor founded on different principles, from

that which appears in human nature. It is necessary in the first place,

that there be some impression immediately present to their memory or

senses, in order to be the foundation of their judgment. From the

tone of voice the dog infers his masters anger, and foresees his own

punishment. From a certain sensation affecting his smell, he judges his

game not to be far distant from him.

Secondly, The inference he draws from the present impression is built on

experience, and on his observation of the conjunction of objects in past

instances. As you vary this experience, he varies his reasoning. Make

a beating follow upon one sign or motion for some time, and afterwards

upon another; and he will successively draw different conclusions,

according to his most recent experience.

Now let any philosopher make a trial, and endeavour to explain that

act of the mind, which we call BELIEF, and give an account of the

principles, from which it is derivd, independent of the influence of

custom on the imagination, and let his hypothesis be equally applicable

to beasts as to the human species; and after he has done this, I promise

to embrace his opinion. But at the same time I demand as an equitable

condition, that if my system be the only one, which can answer to all

these terms, it may be receivd as entirely satisfactory and convincing.

And that it is the only one, is evident almost without any reasoning.

Beasts certainly never perceive any real connexion among objects. It is

therefore by experience they infer one from another. They can never by

any arguments form a general conclusion, that those objects, of which

they have had no experience, resemble those of which they have. It is

therefore by means of custom alone, that experience operates upon them.

All this was sufficiently evident with respect to man. But with respect

to beasts there cannot be the least suspicion of mistake; which must be

ownd to be a strong confirmation, or rather an invincible proof of my

system.

Nothing shews more the force of habit in reconciling us to any

phaenomenoun, than this, that men are not astonished at the operations

of their own reason, at the same time, that they admire the instinct

of animals, and find a difficulty in explaining it, merely because it

cannot be reduced to the very same principles. To consider the matter

aright, reason is nothing but a wonderful and unintelligible instinct in

our souls, which carries us along a certain train of ideas, and endows

them with particular qualities, according to their particular situations

and relations. This instinct, it is true, arises from past observation

and experience; but can any one give the ultimate reason, why past

experience and observation produces such an effect, any more than why

nature alone shoud produce it? Nature may certainly produce whatever

can arise from habit: Nay, habit is nothing but one of the principles of

nature, and derives all its force from that origin.