Thomas Reid.

The works of Thomas Reid, D.D.; now fully collected, with selections from his umpublished letters online

. (page 21 of 114)
Online LibraryThomas ReidThe works of Thomas Reid, D.D.; now fully collected, with selections from his umpublished letters → online text (page 21 of 114)
Font size
QR-code for this ebook


efficient cause ; and for this he thinks he
has the authority of Des Cartes, Locke,
Dr Clarke, Bishop Butler, and many others.
In physicks, and in all its branches, medi-
cine, chymistry, agriculture, the mechani-
cal arts, &c, he thinks the most common
meaning of cause is Hume's notion of it —
to wit, something which goes before the
effect, and is conj oyned with it in the course of
nature. As this notion is vague and popular,
philosophers, when they would speak more
precisely of a cause in physicks, mean by
it some law of nature, of which the phseno-
menon called the effect is a necessary
consequence. Therefore, in writings of
the former kind, he would think himself
warranted to use the word cause, without
addition in the first of these senses ; and, if
he had occasion to use it in the last sense,
he would call it physical cause. In writings
of the last kind, he thinks it may, with pro-
priety, be used without addition in the last
sense -;' and if, in such writings, it be used
in the first sense, he would have it called
the efficient cause. But the additions of
efficient and physical, he does [not] conceive
as denoting two species of the same genus.



* ThiB is in reference to what Dr Gregory says of
trie meaning attached by Reid himself to the word
cause. The passage is as follows : — ,( As little could
he (Hume) have in view the meaning expressed in
the third query, in which meaning Dr Reid (I own
I think with too little regard to the common use and
application of the word cause) hath employed it in
arguing this question ; (* Essays on the Active
Powers,' passim ; ) as where he says, after admitting
that everything must have a cause, that, in the case
of voluntary actions, it is not the motive, but the
person, that is the cause of them. This meaning of
the term cause — to wit, a being having power (and
optional or discretionary powei) to produce or not to
produce a certain change — is not only evidently dif-
ferent from Mr Hume's, but completely repugnant to
his whole system. We may therefore set it aside
too."

It is necessary to quote the queries to which refer,
ence is made in the preceding passage. They are
these: — " It might reasonably be asked — (1°) Is the
word cause employed in that general fourfold sense
mentioned by Aristotle, and applied equally to the
essence or form of a being, to the matter of it, to the
efficient or agent, and to the motive, or purpose, or
final cause? Or (2°) is it employed in its more
common and limited acceptation, as generally used in
physics, and, indeed, in popular discourse, as when we
say, ' Heat is the cause of expansion,' excluding all
the other meanings of it, and particularly that of the
agent? Or (3°) is it employed in that more limited
sense in which it hath been defined and used by
several philosophers, to denote exclusively theagent,
in contradistinction to the physical cause? Or (4°)
is it used to express the vague nation insinuated by
Aristotle's ro e£ ov, comprehending all these already
mentioned, and many more ? For example — what the
parts are to the whole, what a right angle in a tri-
angle is to the proportion between the squares of the
sides of it, what the absence of a pilot is to a ship-
wreck, what the seed is to a plant, what a father is
to his son, what the removal of an opposing cause is
to any event or effect, &c. Ike."— H,



but as distinguishing two different meanings
of the same ambiguous word.

You have good reason to dispute the
maxim about causes, as laid down by Mr
Hume, in whatever sense he takes the word
cause. It is a maxim in natural theology,
universally admitted, that everything that
begins to exist must have a cause, meaning
an efficient cause ; and from this maxim we
easily deduce the existance of a Being who
neither had a cause nor a beginning of ex-
istance, but exists necessarily. Physicks,
in all its branches, is conversant about the
phenomena of nature, and their physical
causes ; and I think it may be admitted as
a maxim that every phenomenon of nature
has a physical cause. But the actions of
men, or of other rational beings, are not
phenomena of nature, nor do they come
within the sphere of physicks. As little is
a beginning of existance a phenomenon of
nature.

Page 154 — " Expressly excluding from
the meaning of the phrase" fyc, to the end of
the paragraph. * My remark upon this para-
graph I ' think more important than any
other I have made on the Essay; and, there-
fore, I beg your attention to it.

Inertia of mind seems to be a very pro-
per name for a quality which, upon every
system of Necessity, must belong to the
mind. It is likewise very proper to explain
the meaning of that term when applied to
the mind.

But when you " expressly exclude from
the meaning of the phrase, the circumstance
of mind remaining or persevering in any
state into which it once gets," I wish you
to consider very seriously whether this con-
cession be not more generous than just ; and,
if it be not just, whether by making it, you
* The whole passage referred to is as follows :—
*' I have occasion often to consider the supposed want
of any such attribute of mind [viz., Power] as this is
the fundamental principle of thedoctrine-ot necessity.
And, for the sake of brevity, and the opposition to
what has been often termed Activity and Force oj
Mind, I call it the Inertia of Mind; limiting, how-
ever, the signification of the phrase, to denote merely
the incapacity of acting optionally or discretion ally
without motives, or in opposition to all motives, or
in any other way but just according to the motives
applied, and expressly excluding from the meaning
of the phrase the circumstance of mind remaining or
persevering in any state into which it once gets, as
body does in a state, either of rest or of uniform
progressive rectilinear motion, into which it is once
put. Such permanency of state does not appear to be
any part of the constitution of the human mind, with
respect to any of iis operations. Sensation of every
kind— memory, imagination, judgment, emotion, or
passion, volition, and involuntary effort — all appear
to be transient conditions, or attributes of mind;
which, of their own nature, independently of any
cause applied, pass away or come to an end. And
this I conceive to be one of the most general circum-
stances of distinction between mere sta-eor condition,
which is predicable ot mind as well as body, (as, for
example, madness, idiotism, vivacity, dulness, pecu-
liar genius, wisdom, knowledge, virtue, vice,) and
those things which are termed acts or operations of
mind or though i - ." — H



LETTERS TO DR JAMES GREGORY.



85



do not much weaken the force of a great
part of your. subsequent reasoning.

The justice of the concession is not evi-
dent to me. To be merely passive, and to
remain in the stale into which it is put, seem
to signify the same thing ; as, on the other
hand, to be active, and to have power to
change its own state, have the same meaning.
If the mind be passive onely, all its changes
are phenomena of nature, and therefore be-
long to the science of physicks, and require
a physical cause, no less than does the
change of direction or of velocity in a moving
body.

Of all things that belong to the mind, its
acts and operations are the onely things
which have any analogy to motion in a body.
The same analogy there is between the
ceasing of any act or operation and the
ceasing of motion. If, therefore, from mere
inactivity, the body, once put in the state of
motion, continues or perseveres in that
state, why should not a mind, which is
equally inactive, being once put in the state
of action or operation, continue in that state ?

You say, " Such permanency of state
does not appear to be the constitution of
the mind in any of its operations.". , I grant
this. But the question is not, " What really
is its constitution ?" but " What would be
its constitution if it were as inert and in-
active as body is ?" To admit this want of
permanency is to admit that the mind is
active in some degree, which is contrary to
the supposition.

The reason why madness, idiotism, &c,
are called states of mind, while its acts and
operationsarenot,* is because mankindhave
always conceived the mind to be passive in
the former and active in the later. But on
the system of Necessity, this distinction has
no place. Both are equally states, onely
the first are not so frequently changed as
the last.

If the concession be just and consistent
with necessity, it must be granted, what-
ever be its consequences ; but I apprehend
theconsequenceswilldeeply affect your essay.

For, first, it contradicts what you have
said, page 336, and, perhaps, in several
other places, that, " according to Mr
Hume's doctrine, a living person, in relation
to motives and actions, is precisely in the
situation of an inanimate body in relation to
projection and gravity." If an inanimate
body had not the quality of persevering in
its state of motion, the effect of projection
and gravity upon it would be very different
from what it is with that quality.

Secondly, by this concession, your reason-
ing from the laws of motion and their cor-
ollaries, is much weakened ; for those laws

• The term State has, more especially of late years,
and principally by Necessitarian philosophers, been
applied to all modifications of mind indifferently. — H.



and corollaries are founded on the supposi-
tion that bodies persevere in the state of
motion as well as of rest ; and, therefore,
are not properly applied to a being which
has not that quality. Indeed, perseverance
in its state is so essential to inertia, that it
will be thought unjustifiable to apply that
name to what you acknowledge does not
persevere in its state. And you will,
perhaps, he charged with giving an invi-
dious epithet to the mind, which, by
your own acknowledgment, is not due, and
then reasoning from that epithet as if it
were due.

226— In the style of physicks, to carry a
letter in the direction A B, and to carry a
letter from A to the point B, are different
things. Any line parallel to A B, is said
to be in the direction A B, though it can-
not lead to the point B.

The case, therefore, here put, is, that the
porter is offered a guinea a-mile to carry a
letter from A to the point B, and half'-a-
guinea a-mile to carry a letter, at the same
time, from A to the point C. And both
motives must necessarely operate according
to their strength. I truely think it impos-
sible to say how the porter would act upon
these suppositions. He would be in an in-
extricable puzzle between contrary actions
and contrary wills.

One should think that the two motives
mentioned, would conjoyn their force in the
diagonal. But, by going in the diagonal,
he loses both the guineas and the half-
guineas ; this is implied in the offer, and is
a motive not to go in the diagonal, as strong
as the two motives for going in it. By the
force of the two motives, he must ivill to go
in the diagonal ; by the force of the third,
he must will not to go in the diagonal.

You pretend to demonstrate that he
must go in the diagonal willingly. I think
it may be demonstrated, with equal force,
that he must will not to go in the diagonal.
I perceive no error in either demonstration ;
and, if both demonstrations be good, what
must be the conclusion ? The conclusion
must be, that the supposition on which both
demonstrations are grounded must be false —
I mean the supposition that motives are the
physical causes of actions ; for it is possible,
and often happens, that, from a false sup-
position, two contradictory conclusions may
be drawn ; but, from a true supposition, it
it impossible.

I think it were better to omit the case
stated toward the end of this page,* because
I think it hardly possible to conceive two
motives, which, being conjoyned, shall have
an analogy to a projectile and centripetal
force conjoyned ; and your concession, that

* This has been done. — H.



86



CORRESPONDENCE OF DR REID.



the effect of a motive is not permanent,
adds to the difficulty. A projectile force
requires a cause to begin it, but it requires
no continuance of the cause — it continues
by the inertia of matter. A centripetal force
is the effect of a cause acting constantly ;
and the effect of that cause must bear some
proportion to the time it acts. Diminish
the time, in infinitum, and the effect of a
centripetal force is diminished, in infinitum ;
so that, in any one instant of time, it bears
no proportion to a projectile force ; and,
what makes the effect of a centripetal, in a
given time, to be capable of comparison with
a projectile, force, is, that the effects of the
centripetal force, during every instant of the
time, are accumulated by the inertia of mat-
ter, and all, as it were, brought into one
sum. Now, how can you conceive two
motives, which have a difference and a re-
lation to each other, corresponding to the
difference and the relation of these two kinds
of force ? Both kinds of force suppose the
permanency of motion once acquired, and,
I think, cannot be distinctly conceived, or
their effects ascertained, without that sup-
position.

337- — Upon the scheme of Necessity,
considered in this section, it must be main-
tained, that there is some unknown cause
or causes of human actions, besides motives,
which sometimes oppose motives with greater
force, sometimes produce actions without
motives ; and, as there are no causes but
physical causes, all actions must be neces-
sary, whether produced by motives or by
other physical causes. This scheme of
Necessity appears, indeed, to me more
tenable than that of H ume and Priestley ;
and I wonder that Mr Hume, who thought
that he had proved, beyond doubt, that we
have no conception of any cause but a physi-
cal cause, did not rest the doctrine of Neces-
sity upon that principle solely. Unknown
causes would have afforded him a retreat in
all attacks upon his system. That motives are
the sole causes of action, is onely an outwork
in the system of Necessity, and may be given
up, while it is maintained that every action
must have a physical cause ; for physical
causes of all human actions, whether they
be known or unknown, are equally inconsist-
ent with liberty.

342. — A physical cause, from its nature,
must be constant in its effects, when it exists,
and is applied to its proper object. But of un-
known causes, the existence and the applica-
tion may depend upon a concurrence of acci-
dents, which is not subject to calculation, or
even to rational conjecture. So that, I
apprehend, the existance of such causes can
never be demonstrated to be contrary to
matter of fact. Unknown causes, like oc-
cult qualities, suit every occasion, and can
never be contradicted by phenomena ; for,



as we cannot, a priori, determine what shall
be the effects of causes absolutely unknown ;
so it is impossible to prove, of any effect
whatsoever, that it cannot be produced by
some unknown physical cause or causes.

The defects of this system of Necessity, I
think, are these two :— first, it is a mere
arbitrary hypothesis, brought to prop a weak
side in the hypothesis of Necessity ; and,
secondly, it is grounded on the supposition
that every event must have a physical cause,
a supposition which demonstrably termin-
ates in an infinite series of physical causes,
every one of which is the effect of a physical
cause.

If the doctrine opposed in this 16th sec-
tion be as it is expressed, page 338 — that,
though the connection of motive and action
is but occasional, the volitions and actions
of men are absolutely produced by motives
as physical causes — this doctrine I take to
be a contradiction in terms, and unworthy
of confutation. It maintains that men are
absolutely determined by motives, and yet
onely occasionally determined by motives —
which, if I understand it right, is a contra-
diction.

351. The case supposed in this page seems
perfectly similar to that of page 226 ; the
same reasoning is applied to both- Should
not the conclusion be the same in both ?

431. — Is there not some inaccuracy in the
reasoning in this and the next page ? I take
X and Y to represent equal motives to action,
and V a motive to inaction, which equally
opposes both. If this be so, the motives to
the opposite action stand thus : X — V 4- Z
on one side, and Y — V on the other. Then
there will be a preponderancy on the side
of X as long as X and its equal Y is greater
than V ; and if X be withdrawn on one
side, and Y on the other, we shall have
— V -!- Z opposed to — V. In this case, if Z
be equal to V, the motives to act and not
to act on the side of Z will be equal ; if Z
be less than V, the strongest motive will be
for inaction ; and if Z be greater than V,
there will be a preponderating motive to act
on the side of Z

As to the style in general, the only fault
I find is, that it abounds too much in long
and complex sentences, which have so many
clauses, and so much meaning, that it is
difficult to carry it all from the beginning to
the end of the sentence. The reader's un-
derstanding should have gentle exercise'but
not hard labour, to comprehend the author's
meaning. I dislike a style that is cut down
into what the ancients called commas of a
line or half a line. This, like water falling
drop by drop, disposes one to sleep. But I
think you rather go into the contrary ex-
treme. Your friend, Lord Bacon, says,
" A fiuent and luxuriant speech becomes
youth well, but not age." I believe he had



LETTERS TO DR JAMES GREGORY.



«7



in his view a rhetorical speech, and not the
lene et temperatum dicendi genus, which,
in Cicero's judgment, best suits philosophy.



XX.

ON A NOVEL USB OP THE WORD MOTIVE —
CAUSALITY OP MOTIVES, &C.

1793.

Dear Sik — I received Mr Crombie's
Essay* on Friday the 11th, at night, and
have read it twice, though interrupted by
the removal of my family to the college.
If this be Mr Crombie's first essay in con-
troversy, I third; he shews no mean talent,
and may in time become an able champion.

He has done me particular honour in
directing so great a part of the book against
me ; yet, though I read the work without
prejudice, my opinion is not changed in any
point of the controversy.

He has strengthenedhis defensive armour
by extending the meaning of the word mo-
tive. I understood a motive, when applied
to a human being, to be that for the sake of
which f he acts, and, therefore, that what he
never was conscious of, can no more be a
motive to determine his will, than it can be
an argument to convince his judgment.

Now, I learn that any circumstance
arising from habit, or some mechanical in-
stinctive cause, may be a motive, though it
never entered into the thought of the agent.

From this reinforcement of motives, of
which we are unconscious, every volition
may be supplied with a motive, and even a
predominant one, when it is wanted.

Yet this addition to his defensive force
takes just as much from his offensive.

The chief argument for Necessity used
by D. Hume and Lord Kames is, that, from
experience, it appears that men are always
determined by the strongest motive. This
argument admits of much embellishment by
a large and pleasant induction.

* Dr Crombie, the well-known author of the
" Gymnasium," and other able works, published an
" Essay on Philosophical Necessity," London, 1793,
in which Dr Gregory's reasoning is assailed with
much acrimony and considerable acuteness. It is
to this treatise that Reid's remarks apply. There
subsequently appeared, " Letters .from Dr James
Gregory of Edinburgh, in Defence of his lissay on the
Difference ol'thc relation between Motiveand Action,
and that of Cause and Effect in Physic* ; with Replies
by the Rev. Alexander Crombie, LL.D.;" London,
1819. It is much to be regretted, that Dr Gregory
did not find leisure to complete his " Answer to
Messrs Crombie, Priestley, and Co. j" of which 512
pages have been printed, but are still unpublished.

f This is Aristotle's definition (to 'inxu oZ) of end
or final causr; and, as a synonyme for end or final
cause, the term motive had been long exclusively
employed. There are two schemes of Necessity —
the Necessi'ation by efficient— the Necessitation by
final causes The former is brute or blind Fate ; the
latter rational Determinism. Though their practical
results be the same, thev ought to be carefully dis-
tinguished in theory.— H.



After these two authors had exhausted
their eloquence upon it, Mr Crombie adds
his, from page 27 to 39. Now, if motives
we are unconscious of be the cause of many
actions, it will be impossible to prove from
experience, that they are all caused by mo-
tives. For no experiment can be made
upon motives we are unconscious of. If,
on the contrary, all our actions are found
by experience to proceed from motives
known or felt, there is no work left for the
unknown, nor any evidence of their exist-
ance. I apprehend, therefore, Mr Crombie
must either keep by the old meaning of
motive, or give up this argument for Neces-
sity taken from experience.

But helaysthemain stress, as Dr Priestley
likewise has done, upon another argument.
It is, that a volition not determined by mo-
tives, is an uncaused effect, and therefore
an absurdity, a contradiction, and the greatest
of all absurdities.

I think, indeed, it is in vain to reason upon
the subject of Necessity pro or con, till this
point be determined ; for, on the one side, to
what purpose is[it] to disprove by argument
a. proposition that is absurd ? On the other
side, demonstration itself cannot prove that
to be true which is absurd.

If this be really an absurdity, Liberty must
be given up. And if the appearance of
absurdity be owing to false colouring, I think
every argument this author has used, when
weighed in the balance of reason, will be
found light.

I would, therefore, think it a prudent
saving of time and labour, that controvertists
on both sides should lay aside every other
weapon, till the force of this be fairly tried.
Mr Crombie triumphs in it almost in every
page ; and I think Dr Priestley urged it as
an apology for neglecting your essay, that
you pretended to demonstrate an absurdity.
It must, indeed, be granted, that even
the Deity cannot give a power to man,
which involves an absurdity. But if this
absurdity vanish, when seen in a just light,
then it will be time to examine the fact,
whether such a power is given to man or not.

Is a volition, undetermined by motives,
an uncaused effect, and therefore an ab-
surdity and a contradiction ?

I grant that an uncaused effect is a con-
tradiction in terms ; for an effect is some-
thing effected, and what is effected implies
an efficient, as an action implies an agent.
To say an effect must have a cause, is
really an identical proposition, which carries
no information but of the meaning of a word.
To say that an event — that is, a thing which
began to exist — must have a cause, is not an
identical proposition, and might have been
as easily said. I know [no] reason why
Mr Crombie should stick by this impro-
priety, after it was censured in Dr Priestley,



88



CORRESPONDENCE OF DR REID.



but that impropriety in the use of terms
is an expedient either to cover an absurdity
where it really is, or to make that appear
absurd which is not so in reality.

I grant, then, that an effect uncaused is
a contradiction, and that an event uncaused
is an absurdity. The question that remains
is whether a volition, undetermined by mo-
tives, is an event uncaused. This I deny.
The cause of the volition is the man that
willed it. This Mr Crombie grants in
several places of his Essay — that the man is
the efficient cause of all his volitions. Is it
not strange, then, that, almost in every page,
he should affirm that a volition, undeter-
mined by motives, is an effect uncaused ?
Is an efficient cause no cause ? or are two
causes necessary to every event ?* Motives,
he thinks, are not the efficient but the physi-
cal cause of volitions, as gravity is of the
descent of a stone. Then, fair dealing
would have made him qualify the absurdity,
and, say that it is absurd that a volition
should be without a physical cause ; but to
have pleaded the absurdity thus qualified,
would have been a manifest petitio principii,

I can see nothing in a physical cause but
a constant conjunction with the effect. Mr



Online LibraryThomas ReidThe works of Thomas Reid, D.D.; now fully collected, with selections from his umpublished letters → online text (page 21 of 114)