Chapter XII (3)

80 It would be difficult to name a man more remarkable at once for the
greatness and the wide range of his mental accomplishments, than
Leibnitz. Yet this eminent man gave as a reason for rejecting
Newton’s scheme of the solar system, that God _could not_ make a
body revolve round a distant centre, unless either by some impelling
mechanism, or by miracle: “Tout ce qui n’est pas explicable,” says
he in a letter to the Abbé Conti, “par la nature des créatures, est
miraculeux. Il ne suffit pas de dire: Dieu a fait une telle loi de
nature; donc la chose est naturelle. Il faut que la loi soit
exécutable par les natures des créatures. Si Dien donnait cette loi,
par exemple, à un corps libre, de tourner à l’entour d’un certain
centre, _il faudrait ou qu’il y joignît d’autres corps qui par leur
impulsion l’obligeassent de rester toujours dans son orbite
circulaire, ou qu’il mît un ange à ses trousses, ou enfin il
faudrait qu’il y concourût extraordinairement_; car naturellement il
s’écartera par la tangente.”—_Works of Leibnitz_, ed. Dutens, iii.,
446.

_ 81 Novum Organum Renovatum_, pp. 32, 33.

_ 82 History of Scientific Ideas_, i., 264.

83 Ibid., i., 263.

84 Ibid., 240.

_ 85 Hist. Scientific Ideas_, ii., 25, 26.

_ 86 Phil. of Disc._, p. 339.

_ 87 Phil. of Disc._, p. 338.

88 Ibid., p. 463.

_ 89 Phil. of Disc._, pp. 472, 473.

90 The _Quarterly Review_ for June, 1841, contained an article of great
ability on Dr. Whewell’s two great works (since acknowledged and
reprinted in Sir John Herschel’s Essays) which maintains, on the
subject of axioms, the doctrine advanced in the text, that they are
generalizations from experience, and supports that opinion by a line
of argument strikingly coinciding with mine. When I state that the
whole of the present chapter (except the last four pages, added in
the fifth edition) was written before I had seen the article (the
greater part, indeed, before it was published), it is not my object
to occupy the reader’s attention with a matter so unimportant as the
degree of originality which may or may not belong to any portion of
my own speculations, but to obtain for an opinion which is opposed
to reigning doctrines, the recommendation derived from a striking
concurrence of sentiment between two inquirers entirely independent
of one another. I embrace the opportunity of citing from a writer of
the extensive acquirements in physical and metaphysical knowledge
and the capacity of systematic thought which the article evinces,
passages so remarkably in unison with my own views as the following:

“The truths of geometry are summed up and embodied in its
definitions and axioms.... Let us turn to the axioms, and what do we
find? A string of propositions concerning magnitude in the abstract,
which are equally true of space, time, force, number, and every
other magnitude susceptible of aggregation and subdivision. Such
propositions, where they are not mere definitions, as some of them
are, carry their inductive origin on the face of their
enunciation.... Those which declare that two straight lines can not
inclose a space, and that two straight lines which cut one another
can not both be parallel to a third, are in reality the only ones
which express characteristic properties of space, and these it will
be worth while to consider more nearly. Now the only clear notion we
can form of straightness is uniformity of direction, for space in
its ultimate analysis is nothing but an assemblage of distances and
directions. And (not to dwell on the notion of continued
contemplation, _i.e._, mental experience, as included in the very
idea of uniformity; nor on that of transfer of the contemplating
being from point to point, and of experience, during such transfer,
of the homogeneity of the interval passed over) we can not even
propose the proposition in an intelligible form to any one whose
experience ever since he was born has not assured him of the fact.
The unity of direction, or that we can not march from a given point
by more than one path direct to the same object, is matter of
practical experience long before it can by possibility become matter
of abstract thought. _We can not attempt mentally to exemplify the
conditions of the assertion in an imaginary case opposed to it,
without violating our habitual recollection of this experience, and
defacing our mental picture of space as grounded on it._ What but
experience, we may ask, can possibly assure us of the homogeneity of
the parts of distance, time, force, and measurable aggregates in
general, on which the truth of the other axioms depends? As regards
the latter axiom, after what has been said it must be clear that the
very same course of remarks equally applies to its case, and that
its truth is quite as much forced on the mind as that of the former
by daily and hourly experience, ... _including always, be it
observed, in our notion of experience, that which is gained by
contemplation of the inward picture which the mind forms to itself
in any proposed case, or which it arbitrarily selects as an
example—such picture, in virtue of the extreme simplicity of these
primary relations, being called up by the imagination with as much
vividness and clearness as could be done by any external impression,
which is the only meaning we can attach to the word intuition, as
applied to such relations_.”

And again, of the axioms of mechanics: “As we admit no such
propositions, other than as truths inductively collected from
observation, even in geometry itself, it can hardly be expected
that, in a science of obviously contingent relations, we should
acquiesce in a contrary view. Let us take one of these axioms and
examine its evidence: for instance, that equal forces
perpendicularly applied at the opposite ends of equal arms of a
straight lever will balance each other. What but experience, we may
ask, in the first place, can possibly inform us that a force so
applied will have any tendency to turn the lever on its centre at
all? or that force can be so transmitted along a rigid line
perpendicular to its direction, as to act elsewhere in space than
along its own line of action? Surely this is so far from being
self-evident that it has even a paradoxical appearance, which is
only to be removed by giving our lever thickness, material
composition, and molecular powers. Again, we conclude, that the two
forces, being equal and applied under precisely similar
circumstances, must, if they exert any effort at all to turn the
lever, exert equal and opposite efforts: but what _a priori_
reasoning can possibly assure us that they _do_ act under precisely
similar circumstances? that points which differ in place _are_
similarly circumstanced as regards the exertion of force? that
universal space may not have relations to universal force—or, at all
events, that the organization of the material universe may not be
such as to place that portion of space occupied by it in such
relations to the forces exerted in it, as may invalidate the
absolute similarity of circumstances assumed? Or we may argue, what
have we to do with the notion of angular movement in the lever at
all? The case is one of rest, and of quiescent destruction of force
by force. Now how is this destruction effected? Assuredly by the
counter-pressure which supports the fulcrum. But would not this
destruction equally arise, and by the same amount of counteracting
force, if each force simply pressed its own half of the lever
against the fulcrum? And what can assure us that it is not so,
except removal of one or other force, and consequent tilting of the
lever? The other fundamental axiom of statics, that the pressure on
the point of support is the sum of the weights ... is merely a
scientific transformation and more refined mode of stating a coarse
and obvious result of universal experience, viz., that the weight of
a rigid body is the same, handle it or suspend it in what position
or by what point we will, and that whatever sustains it sustains its
total weight. Assuredly, as Mr. Whewell justly remarks, ‘No one
probably ever made a trial for the purpose of showing that the
pressure on the support is equal to the sum of the weights.’ ... But
it is precisely because in every action of his life from earliest
infancy he has been continually making the trial, and seeing it made
by every other living being about him, that he never dreams of
staking its result on one additional attempt made with scientific
accuracy. This would be as if a man should resolve to decide by
experiment whether his eyes were useful for the purpose of seeing,
by hermetically sealing himself up for half an hour in a metal
case.”

On the “paradox of universal propositions obtained by experience,”
the same writer says: “If there be necessary and universal truths
expressible in propositions of axiomatic simplicity and obviousness,
and having for their subject-matter the elements of all our
experience and all our knowledge, surely these are the truths which,
if experience suggest to us any truths at all, it ought to suggest
most readily, clearly, and unceasingly. If it were a truth,
universal and necessary, that a net is spread over the whole surface
of every planetary globe, we should not travel far on our own
without getting entangled in its meshes, and making the necessity of
some means of extrication an axiom of locomotion.... There is,
therefore, nothing paradoxical, but the reverse, in our being led by
observation to a recognition of such truths, as _general_
propositions, co-extensive at least with all human experience. That
they pervade all the objects of experience, must insure their
continual suggestion _by_ experience; that they are true, must
insure that consistency of suggestion, that iteration of
uncontradicted assertion, which commands implicit assent, and
removes all occasion of exception; that they are simple, and admit
of no misunderstanding, must secure their admission by every mind.”

“A truth, necessary and universal, relative to any object of our
knowledge, must verify itself in every instance where that object is
before our contemplation, and if at the same time it be simple and
intelligible, its verification must be obvious. _The sentiment of
such a truth can not, therefore, but be present to our minds
whenever that object is contemplated, and must therefore make a part
of the mental picture or idea of that object which we may on any
occasion summon before our imagination.... All propositions,
therefore, become not only untrue but inconceivable_, if ... axioms
be violated in their enunciation.”

Another eminent mathematician had previously sanctioned by his
authority the doctrine of the origin of geometrical axioms in
experience. “Geometry is thus founded likewise on observation; but
of a kind so familiar and obvious, that the primary notions which it
furnishes might seem intuitive.”—_Sir John Leslie_, quoted by Sir
William Hamilton, _Discourses_, etc., p. 272.

91 Principles of Psychology.

92 Mr. Spencer is mistaken in supposing me to claim any peculiar
“necessity” for this axiom as compared with others. I have corrected
the expressions which led him into that misapprehension of my
meaning.

93 Mr. Spencer, in recently returning to the subject (Principles of
Psychology, new edition, chap. xii.: “The Test of Relative
Validity”), makes two answers to the preceding remarks. One is:

“Were an argument formed by repeating the same proposition over and
over again, it would be true that any intrinsic fallibility of the
postulate would not make the conclusion more untrustworthy than the
first step. But an argument consists of unlike propositions. Now,
since Mr. Mill’s criticism on the Universal Postulate is that in
some cases, which he names, it has proved to be an untrustworthy
test; it follows that in any argument consisting of heterogeneous
propositions, there is a risk, increasing as the number of
propositions increases, that some one of them belongs to this class
of cases, and is wrongly accepted because of the inconceivableness
of its negation.”

No doubt: but this supposes new _premises_ to be taken in. The point
we are discussing is the fallibility not of the premises, but of the
reasoning, as distinguished from the premises. Now the validity of
the reasoning depends always upon the same axiom, repeated (in
thought) “over and over again,” viz., that whatever has a mark, has
what it is a mark of. Even, therefore, on the assumption that this
axiom rests ultimately on the Universal Postulate, and that, the
Postulate not being wholly trustworthy, the axiom may be one of the
cases of its failure; all the risk there is of this is incurred at
the very first step of the reasoning, and is not added to, however
long may be the series of subsequent steps.

I am here arguing, of course, from Mr. Spencer’s point of view. From
my own the case is still clearer; for, in my view, the truth that
whatever has a mark has what it is a mark of, is wholly trustworthy,
and derives none of its evidence from so very untrustworthy a test
as the inconceivability of the negative.

Mr. Spencer’s second answer is valid up to a certain point; it is,
that every prolongation of the process involves additional chances
of casual error, from carelessness in the reasoning operation. This
is an important consideration in the private speculations of an
individual reasoner; and even with respect to mankind at large, it
must be admitted that, though mere oversights in the syllogistic
process, like errors of addition in an account, are special to the
individual, and seldom escape detection, confusion of thought
produced (for example) by ambiguous terms has led whole nations or
ages to accept fallacious reasoning as valid. But this very fact
points to causes of error so much more dangerous than the mere
length of the process, as quite to vitiate the doctrine that the
“test of the relative validities of conflicting conclusions” is the
number of times the fundamental postulate is involved. On the
contrary, the subjects on which the trains of reasoning are longest,
and the assumption, therefore, oftenest repeated, are in general
those which are best fortified against the really formidable causes
of fallacy; as in the example already given of mathematics.

94 Mr. Spencer makes a distinction between conceiving myself looking
into darkness, and conceiving _that I am_ then and there looking
into darkness. To me it seems that this change of the expression to
the form _I am_, just marks the transition from conception to
belief, and that the phrase “to conceive that _I am_,” or “that any
thing _is_,” is not consistent with using the word conceive in its
rigorous sense.

95 I have myself accepted the contest, and fought it out on this
battle-ground, in the eleventh chapter of _An Examination of Sir
William Hamilton’s Philosophy._

96 Chap. xi.

97 In one of the three cases, Mr. Spencer, to my no small surprise,
thinks that the belief of mankind “can not be rightly said to have
undergone” the change I allege. Mr. Spencer himself still thinks we
are unable to conceive gravitation acting through empty space. “If
an astronomer avowed that he could conceive gravitative force as
exercised through space absolutely void, my private opinion would be
that he mistook the nature of conception. Conception implies
representation. Here the elements of the representation are the two
bodies and an agency by which either affects the other. To conceive
this agency is to represent it in some terms derived from our
experiences—that is, from our sensations. As this agency gives us no
sensations, we are obliged (if we try to conceive it) to use symbols
idealized from our sensations—imponderable units forming a medium.”

If Mr. Spencer means that the action of gravitation gives us no
sensations, the assertion is one than which I have not seen, in the
writings of philosophers, many more startling. What other sensation
do we need than the sensation of one body moving toward another?
“The elements of the representation” are not two bodies and an
“agency,” but two bodies and an effect; viz., the fact of their
approaching one another. If we are able to conceive a vacuum, is
there any difficulty in conceiving a body falling to the earth
through it?

_ 98 Discussions_, etc., 2d ed., p. 624.

99 Professor Bain (_Logic_, i., 16) identifies the Principle of
Contradiction with his Law of Relativity, viz., that “every thing
that can be thought of, every affirmation that can be made, has an
opposite or counter notion or affirmation;” a proposition which is
one of the general results of the whole body of human experience.
For further considerations respecting the axioms of Contradiction
and Excluded Middle, see the twenty-first chapter of _An Examination
of Sir William Hamilton’s Philosophy_.

100 Dr. Whewell thinks it improper to apply the term Induction to any
operation not terminating in the establishment of a general truth.
Induction, he says (_Philosophy of Discovery_, p. 245), “is not the
same thing as experience and observation. Induction is experience or
observation _consciously_ looked at in a _general_ form. This
consciousness and generality are necessary parts of that knowledge
which is science.” And he objects (p. 241) to the mode in which the
word Induction is employed in this work, as an undue extension of
that term “not only to the cases in which the general induction is
consciously applied to a particular instance, but to the cases in
which the particular instance is dealt with by means of experience
in that rude sense in which experience can be asserted of brutes,
and in which of course we can in no way imagine that the law is
possessed or understood as a general proposition.” This use of the
term he deems a “confusion of knowledge with practical tendencies.”

I disclaim, as strongly as Dr. Whewell can do, the application of
such terms as induction, inference, or reasoning, to operations
performed by mere instinct, that is, from an animal impulse, without
the exertion of any intelligence. But I perceive no ground for
confining the use of those terms to cases in which the inference is
drawn in the forms and with the precautions required by scientific
propriety. To the idea of Science, an express recognition and
distinct apprehension of general laws as such, is essential: but
nine-tenths of the conclusions drawn from experience in the course
of practical life, are drawn without any such recognition: they are
direct inferences from known cases, to a case supposed to be
similar. I have endeavored to show that this is not only as
legitimate an operation, but substantially the same operation, as
that of ascending from known cases to a general proposition; except
that the latter process has one great security for correctness which
the former does not possess. In science, the inference must
necessarily pass through the intermediate stage of a general
proposition, because Science wants its conclusions for record, and
not for instantaneous use. But the inferences drawn for the guidance
of practical affairs, by persons who would often be quite incapable
of expressing in unexceptionable terms the corresponding
generalizations, may and frequently do exhibit intellectual powers
quite equal to any which have ever been displayed in science; and if
these inferences are not inductive, what are they? The limitation
imposed on the term by Dr. Whewell seems perfectly arbitrary;
neither justified by any fundamental distinction between what he
includes and what he desires to exclude, nor sanctioned by usage, at
least from the time of Reid and Stewart, the principal legislators
(as far as the English language is concerned) of modern metaphysical
terminology.

101 Supra, p. 145.

_ 102 Novum Organum Renovatum_, pp. 72, 73.

_ 103 Novum Organum Renovatum_, p. 32.

_ 104 Cours de Philosophie Positive_, vol. ii., p. 202.

105 Dr. Whewell, in his reply, contests the distinction here drawn, and
maintains, that not only different descriptions, but different
explanations of a phenomenon, may all be true. Of the three theories
respecting the motions of the heavenly bodies, he says (_Philosophy
of Discovery_, p. 231): “Undoubtedly all these explanations may be
true and consistent with each other, and would be so if each had
been followed out so as to show in what manner it could be made
consistent with the facts. And this was, in reality, in a great
measure done. The doctrine that the heavenly bodies were moved by
vortices was successfully modified, so that it came to coincide in
its results with the doctrine of an inverse-quadratic centripetal
force.... When this point was reached, the vortex was merely a
machinery, well or ill devised, for producing such a centripetal
force, and therefore did not contradict the doctrine of a
centripetal force. Newton himself does not appear to have been
averse to explaining gravity by impulse. So little is it true that
if one theory be true the other must be false. The attempt to
explain gravity by the impulse of streams of particles flowing
through the universe in all directions, which I have mentioned in
the _Philosophy_, is so far from being inconsistent with the
Newtonian theory, that it is founded entirely upon it. And even with
regard to the doctrine, that the heavenly bodies move by an inherent
virtue; if this doctrine had been maintained in any such way that it
was brought to agree with the facts, the inherent virtue must have
had its laws determined; and then it would have been found that the
virtue had a reference to the central body; and so, the ‘inherent
virtue’ must have coincided in its effect with the Newtonian force;
and then, the two explanations would agree, except so far as the
word ‘inherent’ was concerned. And if such a part of an earlier
theory as this word _inherent_ indicates, is found to be untenable,
it is of course rejected in the transition to later and more exact
theories, in Inductions of this kind, as well as in what Mr. Mill
calls Descriptions. There is, therefore, still no validity
discoverable in the distinction which Mr. Mill attempts to draw
between descriptions like Kepler’s law of elliptical orbits, and
other examples of induction.”

If the doctrine of vortices had meant, not that vortices existed,
but only that the planets moved _in the same manner_ as if they had
been whirled by vortices; if the hypothesis had been merely a mode
of representing the facts, not an attempt to account for them; if,
in short, it had been only a Description; it would, no doubt, have
been reconcilable with the Newtonian theory. The vortices, however,
were not a mere aid to conceiving the motions of the planets, but a
supposed physical agent, actively impelling them; a material fact,
which might be true or not true, but could not be both true and not
true. According to Descartes’s theory it was true, according to
Newton’s it was not true. Dr. Whewell probably means that since the
phrases, centripetal and projectile force, do not declare the nature
but only the direction of the forces, the Newtonian theory does not
absolutely contradict any hypothesis which may be framed respecting
the mode of their production. The Newtonian theory, regarded as a
mere _description_ of the planetary motions, does not; but the
Newtonian theory as an _explanation_ of them does. For in what does
the explanation consist? In ascribing those motions to a general law
which obtains between all particles of matter, and in identifying
this with the law by which bodies fall to the ground. If the planets
are kept in their orbits by a force which draws the particles
composing them toward every other particle of matter in the solar
system, they are not kept in those orbits by the impulsive force of
certain streams of matter which whirl them round. The one
explanation absolutely excludes the other. Either the planets are
not moved by vortices, or they do not move by a law common to all
matter. It is impossible that both opinions can be true. As well
might it be said that there is no contradiction between the
assertions, that a man died because somebody killed him, and that he
died a natural death.

So, again, the theory that the planets move by a virtue inherent in
their celestial nature, is incompatible with either of the two
others: either that of their being moved by vortices, or that which
regards them as moving by a property which they have in common with
the earth and all terrestrial bodies. Dr. Whewell says that the
theory of an inherent virtue agrees with Newton’s when the word
inherent is left out, which of course it would be (he says) if
“found to be untenable.” But leave that out, and where is the
theory? The word inherent _is_ the theory. When that is omitted,
there remains nothing except that the heavenly bodies move “by a
virtue,” _i.e._, by a power of some sort; or by virtue of their
celestial nature, which directly contradicts the doctrine that
terrestrial bodies fall by the same law.

If Dr. Whewell is not yet satisfied, any other subject will serve
equally well to test his doctrine. He will hardly say that there is
no contradiction between the emission theory and the undulatory
theory of light; or that there can be both one and two
electricities; or that the hypothesis of the production of the
higher organic forms by development from the lower, and the
supposition of separate and successive acts of creation, are quite
reconcilable; or that the theory that volcanoes are fed from a
central fire, and the doctrines which ascribe them to chemical
action at a comparatively small depth below the earth’s surface, are
consistent with one another, and all true as far as they go.

If different explanations of the same fact can not both be true,
still less, surely, can different predictions. Dr. Whewell quarrels
(on what ground it is not necessary here to consider) with the
example I had chosen on this point, and thinks an objection to an
illustration a sufficient answer to a theory. Examples not liable to
his objection are easily found, if the proposition that conflicting
predictions can not both be true, can be made clearer by many
examples. Suppose the phenomenon to be a newly-discovered comet, and
that one astronomer predicts its return once in every 300
years—another once in every 400: can they both be right? When
Columbus predicted that by sailing constantly westward he should in
time return to the point from which he set out, while others
asserted that he could never do so except by turning back, were both
he and his opponents true prophets? Were the predictions which
foretold the wonders of railways and steamships, and those which
averred that the Atlantic could never be crossed by steam
navigation, nor a railway train propelled ten miles an hour, both
(in Dr. Whewell’s words) “true, and consistent with one another?”

Dr. Whewell sees no distinction between holding contradictory
opinions on a question of fact, and merely employing different
analogies to facilitate the conception of the same fact. The case of
different Inductions belongs to the former class, that of different
Descriptions to the latter.

_ 106 Phil. of Discov._, p. 256.

_ 107 Essays on the Pursuit of Truth._

108 In the first edition a note was appended at this place, containing
some criticism on Archbishop Whately’s mode of conceiving the
relation between Syllogism and Induction. In a subsequent issue of
his _Logic_, the Archbishop made a reply to the criticism, which
induced me to cancel part of the note, incorporating the remainder
in the text. In a still later edition, the Archbishop observes in a
tone of something like disapprobation, that the objections,
“doubtless from their being fully answered and found untenable, were
silently suppressed,” and that hence he might appear to some of his
readers to be combating a shadow. On this latter point, the
Archbishop need give himself no uneasiness. His readers, I make bold
to say, will fully credit his mere affirmation that the objections
have actually been made.

But as he seems to think that what he terms the suppression of the
objections ought not to have been made “silently,” I now break that
silence, and state exactly what it is that I suppressed, and why. I
suppressed that alone which might be regarded as personal criticism
on the Archbishop. I had imputed to him the having omitted to ask
himself a particular question. I found that he had asked himself the
question, and could give it an answer consistent with his own
theory. I had also, within the compass of a parenthesis, hazarded
some remarks on certain general characteristics of Archbishop
Whately as a philosopher. These remarks, though their tone, I hope,
was neither disrespectful nor arrogant, I felt, on reconsideration,
that I was hardly entitled to make; least of all, when the instance
which I had regarded as an illustration of them, failed, as I now
saw, to bear them out. The real matter at the bottom of the whole
dispute, the different view we take of the function of the major
premise, remains exactly where it was; and so far was I from
thinking that my opinion had been fully “answered” and was
“untenable,” that in the same edition in which I canceled the note,
I not only enforced the opinion by further arguments, but answered
(though without naming him) those of the Archbishop.

For not having made this statement before, I do not think it needful
to apologize. It would be attaching very great importance to one’s
smallest sayings, to think a formal retractation requisite every
time that one falls into an error. Nor is Archbishop Whately’s
well-earned fame of so tender a quality as to require that in
withdrawing a slight criticism on him I should have been bound to
offer a public _amende_ for having made it.

109 But though it is a condition of the validity of every induction that
there be uniformity in the course of nature, it is not a necessary
condition that the uniformity should pervade all nature. It is
enough that it pervades the particular class of phenomena to which
the induction relates. An induction concerning the motions of the
planets, or the properties of the magnet, would not be vitiated
though we were to suppose that wind and weather are the sport of
chance, provided it be assumed that astronomical and magnetic
phenomena are under the dominion of general laws. Otherwise the
early experience of mankind would have rested on a very weak
foundation; for in the infancy of science it could not be known that
_all_ phenomena are regular in their course.

Neither would it be correct to say that every induction by which we
infer any truth, implies the general fact of uniformity _as
foreknown_, even in reference to the kind of phenomena concerned. It
implies, _either_ that this general fact is already known, _or_ that
we may now know it: as the conclusion, the Duke of Wellington is
mortal, drawn from the instances A, B, and C, implies either that we
have already concluded all men to be mortal, or that we are now
entitled to do so from the same evidence. A vast amount of confusion
and paralogism respecting the grounds of Induction would be
dispelled by keeping in view these simple considerations.

110 Infra, chap. xxi.

111 Infra, chap. xxi., xxii.

112 In strictness, wherever the present constitution of space exists;
which we have ample reason to believe that it does in the region of
the fixed stars.

113 Dr. Whewell (_Phil. of Discov._, p. 246) will not allow these and
similar erroneous judgments to be called inductions; inasmuch as
such superstitious fancies “were not collected from the facts by
seeking a law of their occurrence, but were suggested by an
imagination of the anger of superior powers, shown by such
deviations from the ordinary course of nature.” I conceive the
question to be, not in what manner these notions were at first
suggested, but by what evidence they have, from time to time, been
supposed to be substantiated. If the believers in these erroneous
opinions had been put on their defense, they would have referred to
experience: to the comet which preceded the assassination of Julius
Cæsar, or to oracles and other prophecies known to have been
fulfilled. It is by such appeals to facts that all analogous
superstitions, even in our day, attempt to justify themselves; the
supposed evidence of experience is necessary to their hold on the
mind. I quite admit that the influence of such coincidences would
not be what it is, if strength were not lent to it by an antecedent
presumption; but this is not peculiar to such cases; preconceived
notions of probability form part of the explanation of many other
cases of belief on insufficient evidence. The _a priori_ prejudice
does not prevent the erroneous opinion from being sincerely regarded
as a legitimate conclusion from experience; though it improperly
predisposes the mind to that interpretation of experience.

Thus much in defense of the sort of examples objected to. But it
would be easy to produce instances, equally adapted to the purpose,
and in which no antecedent prejudice is at all concerned. “For many
ages,” says Archbishop Whately, “all farmers and gardeners were
firmly convinced—and convinced of their knowing it by
experience—that the crops would never turn out good unless the seed
were sown during the increase of the moon.” This was induction, but
bad induction; just as a vicious syllogism is reasoning, but bad
reasoning.

114 The assertion, that any and every one of the conditions of a
phenomenon may be and is, on some occasions and for some purposes,
spoken of as the cause, has been disputed by an intelligent reviewer
of this work in the _Prospective Review_ (the predecessor of the
justly esteemed _National Review_), who maintains that “we always
apply the word cause rather to that element in the antecedents which
exercises _force_, and which would _tend_ at all times to produce
the same or a similar effect to that which, under certain
conditions, it would actually produce.” And he says, that “every one
would feel” the expression, that the cause of a surprise was the
sentinel’s being off his post, to be incorrect; but that the
“allurement or force which _drew_ him off his post, might be so
called, because in doing so it removed a resisting power which would
have prevented the surprise.” I can not think that it would be wrong
to say, that the event took place because the sentinel was absent,
and yet right to say that it took place because he was bribed to be
absent. Since the only direct effect of the bribe was his absence,
the bribe could be called the remote cause of the surprise, only on
the supposition that the absence was the proximate cause; nor does
it seem to me that any one (who had not a theory to support) would
use the one expression and reject the other.

The reviewer observes, that when a person dies of poison, his
possession of bodily organs is a necessary condition, but that no
one would ever speak of it as the cause. I admit the fact; but I
believe the reason to be, that the occasion could never arise for so
speaking of it; for when in the inaccuracy of common discourse we
are led to speak of some one condition of a phenomenon as its cause,
the condition so spoken of is always one which it is at least
possible that the hearer may require to be informed of. The
possession of bodily organs is a known condition, and to give that
as the answer, when asked the cause of a person’s death, would not
supply the information sought. Once conceive that a doubt could
exist as to his having bodily organs, or that he were to be compared
with some being who had them not, and cases may be imagined in which
it might be said that his possession of them was the cause of his
death. If Faust and Mephistopheles together took poison, it might be
said that Faust died because he was a human being, and had a body,
while Mephistopheles survived because he was a spirit.

It is for the same reason that no one (as the reviewer remarks)
“calls the cause of a leap, the muscles or sinews of the body,
though they are necessary conditions; nor the cause of a
self-sacrifice, the knowledge which was necessary for it; nor the
cause of writing a book, that a man has time for it, which is a
necessary condition.” These conditions (besides that they are
antecedent _states_, and not proximate antecedent _events_, and are
therefore never the conditions in closest apparent proximity to the
effect) are all of them so obviously implied, that it is hardly
possible there should exist that necessity for insisting on them,
which alone gives occasion for speaking of a single condition as if
it were the cause. Wherever this necessity exists in regard to some
one condition, and does not exist in regard to any other, I conceive
that it is consistent with usage, when scientific accuracy is not
aimed at, to apply the name cause to that one condition. If the only
condition which can be supposed to be unknown is a negative
condition, the negative condition may be spoken of as the cause. It
might be said that a person died for want of medical advice: though
this would not be likely to be said, unless the person was already
understood to be ill, and in order to indicate that this negative
circumstance was what made the illness fatal, and not the weakness
of his constitution, or the original virulence of the disease. It
might be said that a person was drowned because he could not swim;
the positive condition, namely, that he fell into the water, being
already implied in the word drowned. And here let me remark, that
his falling into the water is in this case the only positive
condition: all the conditions not expressly or virtually included in
this (as that he could not swim, that nobody helped him, and so
forth) are negative. Yet, if it were simply said that the cause of a
man’s death was falling into the water, there would be quite as
great a sense of impropriety in the expression, as there would be if
it were said that the cause was his inability to swim; because,
though the one condition is positive and the other negative, it
would be felt that neither of them was sufficient, without the
other, to produce death.

With regard to the assertion that nothing is termed the cause,
except the element which exerts active force; I waive the question
as to the meaning of active force, and accepting the phrase in its
popular sense, I revert to a former example, and I ask, would it be
more agreeable to custom to say that a man fell because his foot
slipped in climbing a ladder, or that he fell because of his weight?
for his weight, and not the motion of his foot, was the active force
which determined his fall. If a person walking out in a frosty day,
stumbled and fell, it might be said that he stumbled because the
ground was slippery, or because he was not sufficiently careful: but
few people, I suppose, would say, that he stumbled because he
walked. Yet the only active force concerned was that which he
exerted in walking: the others were mere negative conditions; but
they happened to be the only ones which there could be any necessity
to state; for he walked, most likely, in exactly his usual manner,
and the negative conditions made all the difference. Again, if a
person were asked why the army of Xerxes defeated that of Leonidas,
he would probably say, because they were a thousand times the
number; but I do not think he would say, it was because they fought,
though that was the element of active force. To borrow another
example, used by Mr. Grove and by Mr. Baden Powell, the opening of
flood-gates is said to be the cause of the flow of water; yet the
active force is exerted by the water itself, and opening the
flood-gates merely supplies a negative condition. The reviewer adds,
“There are some conditions absolutely passive, and yet absolutely
necessary to physical phenomena, viz., the relations of space and
time; and to these no one ever applies the word cause without being
immediately arrested by those who hear him.” Even from this
statement I am compelled to dissent. Few persons would feel it
incongruous to say (for example) that a secret became known because
it was spoken of when A. B. was within hearing; which is a condition
of space: or that the cause why one of two particular trees is
taller than the other, is that it has been longer planted; which is
a condition of time.

115 There are a few exceptions; for there are some properties of objects
which seem to be purely preventive; as the property of opaque
bodies, by which they intercept the passage of light. This, as far
as we are able to understand it, appears an instance not of one
cause counteracting another by the same law whereby it produces its
own effects, but of an agency which manifests itself in no other way
than in defeating the effects of another agency. If we knew on what
other relations to light, or on what peculiarities of structure,
opacity depends, we might find that this is only an apparent, not a
real, exception to the general proposition in the text. In any case
it needs not affect the practical application. The formula which
includes all the negative conditions of an effect in the single one
of the absence of counteracting causes, is not violated by such
cases as this; though, if all counteracting agencies were of this
description, there would be no purpose served by employing the
formula.

116 I mean by this expression, the ultimate laws of nature (whatever
they may be) as distinguished from the derivative laws and from the
collocations. The diurnal revolution of the earth (for example) is
not a part of the constitution of things, because nothing can be so
called which might possibly be terminated or altered by natural
causes.

117 I use the words “straight line” for brevity and simplicity. In
reality the line in question is not exactly straight, for, from the
effect of refraction, we actually see the sun for a short interval
during which the opaque mass of the earth is interposed in a direct
line between the sun and our eyes; thus realizing, though but to a
limited extent, the coveted desideratum of seeing round a corner.

_ 118 Second Burnett Prize Essay_, by Principal Tulloch, p. 25.

_ 119 Letters on the Philosophy of the Human Mind_, First Series, p. 219.

_ 120 Essays_, pp. 206–208.

121 To the universality which mankind are agreed in ascribing to the Law
of Causation, there is one claim of exception, one disputed case,
that of the Human Will; the determinations of which, a large class
of metaphysicians are not willing to regard as following the causes
called motives, according to as strict laws as those which they
suppose to exist in the world of mere matter. This controverted
point will undergo a special examination when we come to treat
particularly of the Logic of the Moral Sciences (Book vi., chap. 2).
In the mean time, I may remark that these metaphysicians, who, it
must be observed, ground the main part of their objection on the
supposed repugnance of the doctrine in question to our
consciousness, seem to me to mistake the fact which consciousness
testifies against. What is really in contradiction to consciousness,
they would, I think, on strict self-examination, find to be, the
application to human actions and volitions of the ideas involved in
the common use of the term Necessity; which I agree with them in
objecting to. But if they would consider that by saying that a
person’s actions _necessarily_ follow from his character, all that
is really meant (for no more is meant in any case whatever of
causation) is that he invariably _does_ act in conformity to his
character, and that any one who thoroughly knew his character could
certainly predict how he would act in any supposable case; they
probably would not find this doctrine either contrary to their
experience or revolting to their feelings. And no more than this is
contended for by any one but an Asiatic fatalist.

122 I believe, however, the accredited authorities do suppose that
molecular motion, equivalent in amount to that which will be
manifested in the combustion of the coal, is actually taking place
during the whole of the long interval, if not in the coal, yet in
the oxygen which will then combine with it. But how purely
hypothetical this supposition is, need hardly be remarked; I venture
to say, unnecessarily and extravagantly hypothetical.

_ 123 Lectures on Metaphysics_, vol. ii., Lect. xxxix., pp. 391–2.

I regret that I can not invoke the authority of Sir William Hamilton
in favor of my own opinions on Causation, as I can against the
particular theory which I am now combating. But that acute thinker
has a theory of Causation peculiar to himself, which has never yet,
as far as I know, been analytically examined, but which, I venture
to think, admits of as complete refutation as any one of the false
or insufficient psychological theories which strew the ground in
such numbers under his potent metaphysical scythe. (Since examined
and controverted in the sixteenth chapter of _An Examination of Sir
William Hamilton’s Philosophy_.)

124 Unless we are to consider as such the following statement, by one of
the writers quoted in the text: “In the case of mental exertion, the
result to be accomplished is _preconsidered_ or meditated, and is
therefore known _a priori_, or before experience.”—(Bowen’s _Lowell
Lectures on the Application of Metaphysical and Ethical Science to
the Evidence of Religion_. Boston, 1849.) This is merely saying that
when we will a thing we have an idea of it. But to have an idea of
what we wish to happen, does not imply a prophetic knowledge that it
will happen. Perhaps it will be said that the _first time_ we
exerted our will, when we had of course no experience of any of the
powers residing in us, we nevertheless must already have known that
we possessed them, since we can not will that which we do not
believe to be in our power. But the impossibility is perhaps in the
words only, and not in the facts; for we may _desire_ what we do not
know to be in our power; and finding by experience that our bodies
move according to our _desire_, we may then, and only then, pass
into the more complicated mental state which is termed will.

After all, even if we had an instinctive knowledge that our actions
would follow our will, this, as Brown remarks, would prove nothing
as to the nature of Causation. Our knowing, previous to experience,
that an antecedent will be followed by a certain consequent, would
not prove the relation between them to be any thing more than
antecedence and consequence.

125 Reid’s _Essays on the Active Powers_, Essay iv., chap. 3.

_ 126 Prospective Review_ for February, 1850.

127 Vide supra, p. 178, note.

_ 128 Westminster Review_ for October, 1855.

129 See the whole doctrine in Aristotle _de Ánimâ_, where the θρεπτικὴ
ψυχὴ is treated as exactly equivalent to θρεπτικὴ δύναμις.

130 It deserves notice that the parts of nature which Aristotle regards
as representing evidence of design, are the Uniformities: the
phenomena in so far as reducible to law. Τύχη and τὸ αὐτομάτον
satisfy him as explanations of the variable element in phenomena,
but their occurring according to a fixed rule can only, to his
conceptions, be accounted for by an Intelligent Will. The common, or
what may be called the instinctive, religious interpretation of
nature, is the reverse of this. The events in which men
spontaneously see the hand of a supernatural being, are those which
can not, as they think, be reduced to a physical law. What they can
distinctly connect with physical causes, and especially what they
can predict, though of course ascribed to an Author of Nature, if
they already recognize such an author, might be conceived, they
think, to arise from a blind fatality, and in any case do not appear
to them to bear so obviously the mark of a divine will. And this
distinction has been countenanced by eminent writers on Natural
Theology, in particular by Dr. Chalmers, who thinks that though
design is present everywhere, the irresistible evidence of it is to
be found not in the _laws_ of nature but in the collocations,
_i.e._, in the part of nature in which it is impossible to trace any
law. A few properties of dead matter might, he thinks, conceivably
account for the regular and invariable succession of effects and
causes; but that the different kinds of matter have been so placed
as to promote beneficent ends, is what he regards as the proof of a
Divine Providence. Mr. Baden Powell, in his Essay entitled
“Philosophy of Creation,” has returned to the point of view of
Aristotle and the ancients, and vigorously re-asserts the doctrine
that the indication of design in the universe is not special
adaptations, but Uniformity and Law, these being the evidences of
mind, and not what appears to us to be a provision for our uses.
While I decline to express any opinion here on this _vexata
quæstio_, I ought not to mention Mr. Powell’s volume without the
acknowledgment due to the philosophic spirit which pervades
generally the three Essays composing it, forming in the case of one
of them (the “Unity of Worlds”) an honorable contrast with the other
dissertations, so far as they have come under my notice, which have
appeared on either side of that controversy.

131 In the words of Fontenelle, another celebrated Cartesian, “les
philosophes aussi bien que le peuple avaient cru que l’âme et le
corps agissaient réellement et physiquement l’un sur l’autre.
Descartes vint, qui prouva que leur nature ne permettait point cette
sorte de communication véritable, et qu’ils n’en pouvaient avoir
qu’une apparente, dont Dieu était le Médiateur.”—(_Œuvres de
Fontenelle_, ed. 1767, tom. v., p. 534.)

132 I omit, for simplicity, to take into account the effect, in this
latter case, of the diminution of pressure, in diminishing the flow
of water through the drain; which evidently in no way affects the
truth or applicability of the principle, since when the two causes
act simultaneously the conditions of that diminution of pressure do
not arise.

133 Professor Bain adds several other well-established chemical
generalizations: “The laws that simple substances exhibit the
strongest affinities; that compounds are more fusible than their
elements; that combination tends to a lower state of matter from gas
down to solid;” and some general propositions concerning the
circumstances which facilitate or resist chemical combination.
(Logic, ii., 254.)

134 Professor Bain (Logic, ii., 39) points out a class of cases, other
than that spoken of in the text, which he thinks must be regarded as
an exception to the Composition of Causes. “Causes that merely make
good the collocation for bringing a prime mover into action, or that
release a potential force, do not follow any such rule. One man may
direct a gun upon a fort as well as three: two sparks are not more
effectual than one in exploding a barrel of gunpowder. In medicine
there is a certain dose that answers the end; and adding to it does
no more good.”

I am not sure that these cases are really exceptions. The law of
Composition of Causes, I think, is really fulfilled, and the
appearance to the contrary is produced by attending to the remote
instead of the immediate effect of the causes. In the cases
mentioned, the immediate effect of the causes in action is a
collocation, and the duplication of the cause does double the
quantity of collocation. Two men could raise the gun to the required
angle twice as quickly as one, though one is enough. Two sparks put
two sets of particles of the gunpowder into the state of intestine
motion which makes them explode, though one is sufficient. It is the
collocation itself that does not, by being doubled, always double
the effect; because in many cases a certain collocation, once
obtained, is all that is required for the production of the whole
amount of effect which can be produced at all at the given time and
place. Doubling the collocation with difference of time and place,
as by pointing two guns, or exploding a second barrel after the
first, does double the effect. This remark applies still more to Mr.
Bain’s third example, that of a double dose of medicine; for a
double dose of an aperient does purge more violently, and a double
dose of laudanum does produce longer and sounder sleep. But a double
purging, or a double amount of narcotism, may have remote effects
different in kind from the effect of the smaller amount, reducing
the case to that of heteropathic laws, discussed in the text.