Chapter V: Of the Law of Universal Causation (2)

§ 8. Since everything which occurs is determined by laws of causation and collocations of the original causes, it follows that the coexistences which are observable among effects cannot be themselves the subject of any similar set of laws, distinct from laws of causation. Uniformities there are, as well of coexistence as of succession, among effects; but these must in all cases be a mere result either of the identity or of the coexistence of their causes: if the causes did not coexist, neither could the effects. And these causes being also effects of prior causes, and these of others, until we reach the primeval causes, it follows that (except in the case of effects which can be traced immediately or remotely to one and the same cause) the coexistences of phenomena can in no case be universal, unless the coexistences of the primeval causes to which the effects are ultimately traceable, can be reduced to an universal law: but we have seen that they cannot. There are, accordingly, no original and independent, in other words no unconditional, uniformities of coexistence, between effects of different causes; if they coexist, it is only because the causes have casually coexisted. The only independent and unconditional coexistences which are sufficiently invariable to have any claim to the character of laws, are between different and mutually independent effects of the same cause; in other words, between different properties of the same natural agent. This portion of the Laws of Nature will be treated of in the latter part of the present Book, under the name of the Specific Properties of Kinds.

§ 9. It is proper in this place to advert to a rather ancient doctrine respecting causation, which has been revived during the last few years in many quarters, and at present gives more signs of life than any other theory of causation at variance with that set forth in the preceding pages.

According to the theory in question, Mind, or, to speak more precisely, Will, is the only cause of phenomena. The type of Causation, as well as the exclusive source from which we derive the idea, is our own voluntary agency. Here, and here only (it is said) we have direct evidence of causation. We know that we can move our bodies. Respecting the phenomena of inanimate nature, we have no other direct knowledge than that of antecedence and sequence. But in the case of our voluntary actions, it is affirmed that we are conscious of power, before we have experience of results. An act of volition, whether followed by an effect or not, is accompanied by a consciousness of effort, "of force exerted, of power in action, which is necessarily causal, or causative." This feeling of energy or force, inherent in an act of will, is knowledge _à priori_; assurance, prior to experience, that we have the power of causing effects. Volition, therefore, it is asserted, is something more than an unconditional antecedent; it is a cause, in a different sense from that in which physical phenomena are said to cause one another: it is an Efficient Cause. From this the transition is easy to the further doctrine, that Volition is the _sole_ Efficient Cause of all phenomena. "It is inconceivable that dead force could continue unsupported for a moment beyond its creation. We cannot even conceive of change or phenomena without the energy of a mind." "The word _action_" itself, says another writer of the same school, "has no real significance except when applied to the doings of an intelligent agent. Let any one conceive, if he can, of any power, energy, or force, inherent in a lump of matter." Phenomena may have the semblance of being produced by physical causes, but they are in reality produced, say these writers, by the immediate agency of mind. All things which do not proceed from a human (or, I suppose, an animal) will, proceed, they say, directly from divine will. The earth is not moved by the combination of a centripetal and a projectile force; this is but a mode of speaking, which serves to facilitate our conceptions. It is moved by the direct volition of an omnipotent Being, in a path coinciding with that which we deduce from the hypothesis of these two forces.

As I have so often observed, the general question of the existence of Efficient Causes does not fall within the limits of our subject: but a theory which represents them as capable of being subjects of human knowledge, and which passes off as efficient causes what are only physical or phenomenal causes, belongs as much to Logic as to Metaphysics, and is a fit subject for discussion here.

To my apprehension, a volition is not an efficient, but simply a physical, cause. Our will causes our bodily actions in the same sense, and in no other, in which cold causes ice, or a spark causes an explosion of gunpowder. The volition, a state of our mind, is the antecedent; the motion of our limbs in conformity to the volition, is the consequent. This sequence I conceive to be not a subject of direct consciousness, in the sense intended by the theory. The antecedent, indeed, and the consequent, are subjects of consciousness. But the connexion between them is a subject of experience. I cannot admit that our consciousness of the volition contains in itself any _à priori_ knowledge that the muscular motion will follow. If our nerves of motion were paralysed, or our muscles stiff and inflexible, and had been so all our lives, I do not see the slightest ground for supposing that we should ever (unless by information from other people) have known anything of volition as a physical power, or been conscious of any tendency in feelings of our mind to produce motions of our body, or of other bodies. I will not undertake to say whether we should in that case have had the physical feeling which I suppose is meant when these writers speak of "consciousness of effort:" I see no reason why we should not; since that physical feeling is probably a state of nervous sensation beginning and ending in the brain, without involving the motory apparatus: but we certainly should not have designated it by any term equivalent to effort, since effort implies consciously aiming at an end, which we should not only in that case have had no reason to do, but could not even have had the idea of doing. If conscious at all of this peculiar sensation, we should have been conscious of it, I conceive, only as a kind of uneasiness, accompanying our feelings of desire.

It is well argued by Sir William Hamilton against the theory in question, that it "is refuted by the consideration, that between the overt fact of corporeal movement of which we are cognisant, and the internal act of mental determination of which we are also cognisant, there intervenes a numerous series of intermediate agencies of which we have no knowledge; and, consequently, that we can have no consciousness of any causal connexion between the extreme links of this chain, the volition to move and the limb moving, as this hypothesis asserts. No one is immediately conscious, for example, of moving his arm through his volition. Previously to this ultimate movement, muscles, nerves, a multitude of solid and fluid parts, must be set in motion by the will, but of this motion we know, from consciousness, absolutely nothing. A person struck with paralysis is conscious of no inability in his limb to fulfil the determinations of his will; and it is only after having willed, and finding that his limbs do not obey his volition, that he learns by this experience, that the external movement does not follow the internal act. But as the paralytic learns after the volition that his limbs do not obey his mind; so it is only after volition that the man in health learns, that his limbs do obey the mandates of his will."[22]

Those against whom I am contending have never produced, and do not pretend to produce, any positive evidence[23] that the power of our will to move our bodies would be known to us independently of experience. What they have to say on the subject is, that the production of physical events by a will seems to carry its own explanation with it, while the action of matter upon matter seems to require something else to explain it; and is even, according to them, "inconceivable" on any other supposition than that some will intervenes between the apparent cause and its apparent effect. They thus rest their case on an appeal to the inherent laws of our conceptive faculty; mistaking, as I apprehend, for the laws of that faculty its acquired habits, grounded on the spontaneous tendencies of its uncultured state. The succession between the will to move a limb and the actual motion, is one of the most direct and instantaneous of all sequences which come under our observation, and is familiar to every moment's experience from our earliest infancy; more familiar than any succession of events exterior to our bodies, and especially more so than any other case of the apparent origination (as distinguished from the mere communication) of motion. Now, it is the natural tendency of the mind to be always attempting to facilitate its conception of unfamiliar facts by assimilating them to others which are familiar. Accordingly, our voluntary acts, being the most familiar to us of all cases of causation, are, in the infancy and early youth of the human race, spontaneously taken as the type of causation in general, and all phenomena are supposed to be directly produced by the will of some sentient being. This original Fetichism I shall not characterize in the words of Hume, or of any follower of Hume, but in those of a religious metaphysician, Dr. Reid, in order more effectually to show the unanimity which exists on the subject among all competent thinkers.

"When we turn our attention to external objects, and begin to exercise our rational faculties about them, we find that there are some motions and changes in them which we have power to produce, and that there are many which must have some other cause. Either the objects must have life and active power, as we have, or they must be moved or changed by something that has life and active power, as external objects are moved by us.

"Our first thoughts seem to be, that the objects in which we perceive such motion have understanding and active power as we have. 'Savages,' says the Abbé Raynal, 'wherever they see motion which they cannot account for, there they suppose a soul.' All men may be considered as savages in this respect, until they are capable of instruction, and of using their faculties in a more perfect manner than savages do.

"The Abbé Raynal's observation is sufficiently confirmed, both from fact, and from the structure of all languages.

"Rude nations do really believe sun, moon, and stars, earth, sea, and air, fountains, and lakes, to have understanding and active power. To pay homage to them, and implore their favour, is a kind of idolatry natural to savages.

"All languages carry in their structure the marks of their being formed when this belief prevailed. The distinction of verbs and participles into active and passive, which is found in all languages, must have been originally intended to distinguish what is really active from what is merely passive; and in all languages, we find active verbs applied to those objects, in which, according to the Abbé Raynal's observation, savages suppose a soul.

"Thus we say the sun rises and sets, and comes to the meridian, the moon changes, the sea ebbs and flows, the winds blow. Languages were formed by men who believed these objects to have life and active power in themselves. It was therefore proper and natural to express their motions and changes by active verbs.

"There is no surer way of tracing the sentiments of nations before they have records, than by the structure of their language, which, notwithstanding the changes produced in it by time, will always retain some signatures of the thoughts of those by whom it was invented. When we find the same sentiments indicated in the structure of all languages, those sentiments must have been common to the human species when languages were invented.

"When a few, of superior intellectual abilities, find leisure for speculation, they begin to philosophize, and soon discover, that many of those objects which at first they believed to be intelligent and active are really lifeless and passive. This is a very important discovery. It elevates the mind, emancipates from many vulgar superstitions, and invites to further discoveries of the same kind.

"As philosophy advances, life and activity in natural objects retires, and leaves them dead and inactive. Instead of moving voluntarily, we find them to be moved necessarily; instead of acting, we find them to be acted upon; and Nature appears as one great machine, where one wheel is turned by another, that by a third; and how far this necessary succession may reach, the philosopher does not know."[24]

There is, then, a spontaneous tendency of the intellect to account to itself for all cases of causation by assimilating them to the intentional acts of voluntary agents like itself. This is the instinctive philosophy of the human mind in its earliest stage, before it has become familiar with any other invariable sequences than those between its own volitions or those of other human beings and their voluntary acts. As the notion of fixed laws of succession among external phenomena gradually establishes itself, the propensity to refer all phenomena to voluntary agency slowly gives way before it. The suggestions, however, of daily life continuing to be more powerful than those of scientific thought, the original instinctive philosophy maintains its ground in the mind, underneath the growths obtained by cultivation, and keeps up a constant resistance to their throwing their roots deep into the soil. The theory against which I am contending derives its nourishment from that substratum. Its strength does not lie in argument, but in its affinity to an obstinate tendency of the infancy of the human mind.

That this tendency, however, is not the result of an inherent mental law, is proved by superabundant evidence. The history of science, from its earliest dawn, shows that mankind have not been unanimous in thinking either that the action of matter upon matter was not conceivable, or that the action of mind upon matter was. To some thinkers, and some schools of thinkers, both in ancient and in modern times, this last has appeared much more inconceivable than the former. Sequences entirely physical and material, as soon as they had become sufficiently familiar to the human mind, came to be thought perfectly natural, and were regarded not only as needing no explanation themselves, but as being capable of affording it to others, and even of serving as the ultimate explanation of things in general.

One of the ablest recent supporters of the Volitional theory has furnished an explanation, at once historically true and philosophically acute, of the failure of the Greek philosophers in physical inquiry, in which, as I conceive, he unconsciously depicts his own state of mind. "Their stumbling-block was one as to the nature of the evidence they had to expect for their conviction.... They had not seized the idea that they must not expect to understand the processes of outward causes, but only their results: and consequently, the whole physical philosophy of the Greeks was an attempt to identify mentally the effect with its cause, to feel after some not only necessary but natural connexion, where they meant by natural that which would _per se_ carry some presumption to their own mind.... They wanted to see some _reason_ why the physical antecedent should produce this particular consequent, and their only attempts were in directions where they could find such reasons."[25] In other words, they were not content merely to know that one phenomenon was always followed by another; they thought that they had not attained the true aim of science, unless they could perceive something in the nature of the one phenomenon from which it might have been known or presumed _previous to trial_ that it would be followed by the other: just what the writer, who has so clearly pointed out their error, thinks that he perceives in the nature of the phenomenon Volition. And to complete the statement of the case, he should have added that these early speculators not only made this their aim, but were quite satisfied with their success in it; not only sought for causes which should carry in their mere statement evidence of their efficiency, but fully believed that they had found such causes. The reviewer can see plainly that this was an error, because _he_ does not believe that there exist any relations between material phenomena which can account for their producing one another: but the very fact of the persistency of the Greeks in this error, shows that their minds were in a very different state: they were able to derive from the assimilation of physical facts to other physical facts, the kind of mental satisfaction which we connect with the word explanation, and which the reviewer would have us think can only be found in referring phenomena to a will. When Thales and Hippo held that moisture was the universal cause, and external element, of which all other things were but the infinitely various sensible manifestations; when Anaximenes predicated the same thing of air, Pythagoras of numbers, and the like, they all thought that they had found a real explanation; and were content to rest in this explanation as ultimate. The ordinary sequences of the external universe appeared to them, no less than to their critic, to be inconceivable without the supposition of some universal agency to connect the antecedents with the consequents; but they did not think that Volition, exerted by minds, was the only agency which fulfilled this requirement. Moisture, or air, or numbers, carried to their minds a precisely similar impression of making intelligible what was otherwise inconceivable, and gave the same full satisfaction to the demands of their conceptive faculty.

It was not the Greeks alone, who "wanted to see some reason why the physical antecedent should produce this particular consequent," some connexion "which would _per se_ carry some presumption to their own mind." Among modern philosophers, Leibnitz laid it down as a self-evident principle that all physical causes without exception must contain in their own nature something which makes it intelligible that they should be able to produce the effects which they do produce. Far from admitting Volition as the only kind of cause which carried internal evidence of its own power, and as the real bond of connexion between physical antecedents and their consequents, he demanded some naturally and _per se_ efficient physical antecedent as the bond of connexion between Volition itself and its effects. He distinctly refused to admit the will of God as a sufficient explanation of anything except miracles; and insisted upon finding something that would account _better_ for the phenomena of nature than a mere reference to divine volition.[26]

Again, and conversely, the action of mind upon matter (which, we are now told, not only needs no explanation itself, but is the explanation of all other effects), has appeared to some thinkers to be itself the grand inconceivability. It was to get over this very difficulty that the Cartesians invented the system of Occasional Causes. They could not conceive that thoughts in a mind could produce movements in a body, or that bodily movements could produce thoughts. They could see no necessary connexion, no relation _à priori_, between a motion and a thought. And as the Cartesians, more than any other school of philosophical speculation before or since, made their own minds the measure of all things, and refused, on principle, to believe that Nature had done what they were unable to see any reason why she must do, they affirmed it to be impossible that a material and a mental fact could be causes one of another. They regarded them as mere Occasions on which the real agent, God, thought fit to exert his power as a Cause. When a man wills to move his foot, it is not his will that moves it, but God (they said) moves it on the occasion of his will. God, according to this system, is the only efficient cause, not _quâ_ mind, or _quâ_ endowed with volition, but _quâ_ omnipotent. This hypothesis was, as I said, originally suggested by the supposed inconceivability of any real mutual action between Mind and Matter: but it was afterwards extended to the action of Matter upon Matter, for on a nicer examination they found this inconceivable too, and therefore, according to their logic, impossible. The _deus ex machinâ_ was ultimately called in to produce a spark on the occasion of a flint and steel coming together, or to break an egg on the occasion of its falling on the ground.

All this, undoubtedly, shows that it is the disposition of mankind in general, not to be satisfied with knowing that one fact is invariably antecedent and another consequent, but to look out for something which may seem to explain their being so. But we also see that this demand may be completely satisfied by an agency purely physical, provided it be much more familiar than that which it is invoked to explain. To Thales and Anaximenes, it appeared inconceivable that the antecedents which we see in nature, should produce the consequents; but perfectly natural that water, or air, should produce them. The writers whom I oppose declare this inconceivable, but can conceive that mind, or volition, is _per se_ an efficient cause: while the Cartesians could not conceive even that, but peremptorily declared that no mode of production of any fact whatever was conceivable, except the direct agency of an omnipotent being. Thus giving additional proof of what finds new confirmation in every stage of the history of science: that both what persons can, and what they cannot, conceive, is very much an affair of accident, and depends altogether on their experience, and their habits of thought; that by cultivating the requisite associations of ideas, people may make themselves unable to conceive any given thing; and may make themselves able to conceive most things, however inconceivable these may at first appear: and the same facts in each person's mental history which determine what is or is not conceivable to him, determine also which among the various sequences in nature will appear to him so natural and plausible, as to need no other proof of their existence; to be evident by their own light, independent equally of experience and of explanation.

By what rule is any one to decide between one theory of this description and another? The theorists do not direct us to any external evidence; they appeal each to his own subjective feelings. One says, the succession C, B, appears to me more natural, conceivable, and credible _per se_, than the succession A, B; you are therefore mistaken in thinking that B depends upon A; I am certain, though I can give no other evidence of it, that C comes in between A and B, and is the real and only cause of B. The other answers--the successions C, B, and A, B, appear to me equally natural and conceivable, or the latter more so than the former: A is quite capable of producing B without any other intervention. A third agrees with the first in being unable to conceive that A can produce B, but finds the sequence D, B, still more natural than C, B, or of nearer kin to the subject matter, and prefers his D theory to the C theory. It is plain that there is no universal law operating here, except the law that each person's conceptions are governed and limited by his individual experience and habits of thought. We are warranted in saying of all three, what each of them already believes of the other two, namely, that they exalt into an original law of the human intellect and of outward nature, one particular sequence of phenomena, which appears to them more natural and more conceivable than other sequences, only because it is more familiar. And from this judgment I am unable to except the theory, that Volition is an Efficient Cause.

I am unwilling to leave the subject without adverting to the additional fallacy contained in the corollary from this theory; in the inference that because Volition is an efficient cause, therefore it is the only cause, and the direct agent in producing even what is apparently produced by something else. Volitions are not known to produce anything directly except nervous action, for the will influences even the muscles only through the nerves. Though it were granted, then, that every phenomenon has an efficient, and not merely a phenomenal cause, and that volition, in the case of the peculiar phenomena which are known to be produced by it, is that efficient cause; are we therefore to say, with these writers, that since we know of no other efficient cause, and ought not to assume one without evidence, there _is_ no other, and volition is the direct cause of all phenomena? A more outrageous stretch of inference could hardly be made. Because among the infinite variety of the phenomena of nature there is one, namely, a particular mode of action of certain nerves, which has for its cause, and as we are now supposing for its efficient cause, a state of our mind; and because this is the only efficient cause of which we are conscious, being the only one of which in the nature of the case we _can_ be conscious, since it is the only one which exists within ourselves; does this justify us in concluding that all other phenomena must have the same kind of efficient cause with that one eminently special, narrow, and peculiarly human or animal, phenomenon? The nearest parallel to this specimen of generalization is suggested by the recently revived controversy on the old subject of Plurality of Worlds, in which the contending parties have been so conspicuously successful in overthrowing one another. Here also we have experience only of a single case, that of the world in which we live, but that this is inhabited we know absolutely, and without possibility of doubt. Now if on this evidence any one were to infer that every heavenly body without exception, sun, planet, satellite, comet, fixed star or nebula, is inhabited, and must be so from the inherent constitution of things, his inference would exactly resemble that of the writers who conclude that because volition is the efficient cause of our own bodily motions, it must be the efficient cause of everything else in the universe. It is true there are cases in which, with acknowledged propriety, we generalize from a single instance to a multitude of instances. But they must be instances which resemble the one known instance, and not such as have no circumstance in common with it except that of being instances. I have, for example, no direct evidence that any creature is alive except myself: yet I attribute, with full assurance, life and sensation to other human beings and animals. But I do not conclude that all other things are alive merely because I am. I ascribe to certain other creatures a life like my own, because they manifest it by the same sort of indications by which mine is manifested. I find that their phenomena and mine conform to the same laws, and it is for this reason that I believe both to arise from a similar cause. Accordingly I do not extend the conclusion beyond the grounds for it. Earth, fire, mountains, trees, are remarkable agencies, but their phenomena do not conform to the same laws as my actions do, and I therefore do not believe earth or fire, mountains or trees, to possess animal life. But the supporters of the Volition Theory ask us to infer that volition causes everything, for no reason except that it causes one particular thing; although that one phenomenon, far from being a type of all natural phenomena, is eminently peculiar; its laws bearing scarcely any resemblance to those of any other phenomenon, whether of inorganic or of organic nature.

NOTE SUPPLEMENTARY TO THE PRECEDING CHAPTER.

The author of the Second Burnett Prize Essay (Dr. Tulloch), who
has employed a considerable number of pages in controverting
the doctrines of the preceding chapter, has somewhat surprised
me by denying a fact, which I imagined too well known to
require proof--that there have been philosophers who found in
physical explanations of phenomena the same complete mental
satisfaction which we are told is only given by volitional
explanation, and others who denied the Volitional Theory on the
same ground of inconceivability on which it is defended. The
assertion of the Essayist is countersigned still more
positively by an able reviewer of the Essay:[27] "Two
illustrations," says the reviewer, "are advanced by Mr. Mill:
the case of Thales and Anaximenes, stated by him to have
maintained, the one Moisture and the other Air to be the origin
of all things; and that of Descartes and Leibnitz, whom he
asserts to have found the action of Mind upon Matter the grand
inconceivability. In counterstatement as to the first of these
cases the author shows--what we believe now hardly admits of
doubt--that the Greek philosophers distinctly recognised as
beyond and above their primal material source, the [Greek:
nous], or Divine Intelligence, as the efficient and originating
Source of all: and as to the second, by proof that it was the
_mode_, not the _fact_, of that action on matter, which was
represented as inconceivable."

A greater quantity of historical error has seldom been
comprised in a single sentence. With regard to Thales, the
assertion that he considered water as a mere material in the
hands of [Greek: nous] rests on a passage of Cicero _de Naturâ
Deorum_: and whoever will refer to any of the accurate
historians of philosophy, will find that they treat this as a
mere fancy of Cicero, resting on no authority, opposed to all
the evidence; and make surmises as to the manner in which
Cicero may have been led into the error. (See Ritter, vol. i.
p. 211, 2nd ed.; Brandis, vol. i. pp. 118-9, 1st ed.; Preller,
_Historia Philosophiæ Græco-Romanæ_, p. 10. "Schiefe Ansicht,
durchaus zu verwerfen;" "augenscheinlich folgernd statt zu
berichten;" "quibus vera sententia Thaletis plane detorquetur;"
are the expressions of these writers.) As for Anaximenes, he,
even according to Cicero, maintained, not that air was the
material out of which God made the world, but that the air was
a god: "Anaximenes aëra deum statuit:" or according to St.
Augustine, that it was the material out of which the gods were
made; "non tamen ab ipsis [Diis] aërem factum, sed ipsos ex
aëre ortos credidit." Those who are not familiar with the
metaphysical terminology of antiquity, must not be misled by
finding it stated that Anaximenes attributed [Greek: psychê]
(translated _soul_, or _life_) to his universal element, the
air. The Greek philosophers acknowledged several kinds of
[Greek: psychê], the nutritive, the sensitive, and the
intellective.[28] Even the moderns with admitted correctness
attribute life to plants. As far as we can make out the meaning
of Anaximenes, he made choice of Air as the universal agent, on
the ground that it is perpetually in motion, without any
apparent cause external to itself: so that he conceived it as
exercising spontaneous force, and as the principle of life and
activity in all things, men and gods inclusive. If this be not
representing it as the Efficient Cause, the dispute altogether
has no meaning.

If either Anaximenes, or Thales, or any of their cotemporaries,
had held the doctrine that [Greek: nous] was the Efficient
Cause, that doctrine could not have been reputed, as it was
throughout antiquity, to have originated with Anaxagoras. The
testimony of Aristotle, in the first book of his Metaphysics,
is perfectly decisive with respect to these early speculations.
After enumerating four kinds of causes, or rather four
different meanings of the word Cause, viz. the Essence of a
thing, the Matter of it, the Origin of Motion (Efficient
Cause), and the End or Final Cause, he proceeds to say, that
most of the early philosophers recognised only the second kind
of Cause, the Matter of a thing, [Greek: tas en hylês eidei
monas ôêthêsan archas einai pantôn]. As his first example he
specifies Thales, whom he describes as taking the lead in this
view of the subject, [Greek: ho tês toiautês archêgos
philosophias], and goes on to Hippon, Anaximenes, Diogenes (of
Apollonia), Hippasus of Metapontum, Heraclitus, and Empedocles.
Anaxagoras, however, (he proceeds to say,) taught a different
doctrine, as we know, and it is _alleged_ that Hermotimus of
Clazomenæ taught it before him. Anaxagoras represented, that
even if these various theories of the universal material were
true, there would be need of some other cause to account for
the transformations of the material, since the material cannot
originate its own changes: [Greek: ou gar dê to ge hypokeimenon
auto poiei metaballein heauto; legô d' oion oute to xylon oute
ho chalkos aitios tou metaballein hekateron autôn, oude poiei
to men xylon klinên ho de chalkos andrianta, all' heteron ti
tês metabolês aition], viz., the other kind of cause [Greek:
hothen hê archê tês kinêseôs]--an Efficient Cause. Aristotle
expresses great approbation of this doctrine (which he says
made its author appear the only sober man among persons raving,
[Greek: oion nêphôn ephanê par' eikê legontas tous proteron]);
but while describing the influence which it exercised over
subsequent speculation, he remarks that the philosophers
against whom this, as he thinks, insuperable difficulty was
urged, had not felt it to be any difficulty: [Greek: ouden
edyscheranan en heautois]. It is surely unnecessary to say more
in proof of the matter of fact which Dr. Tulloch and his
reviewer deny.

Having pointed out what he thinks the error of these early
speculators in not recognising the need of an efficient cause,
Aristotle goes on to mention two other efficient causes to
which they might have had recourse, instead of intelligence:
[Greek: tychê], chance, and [Greek: to automaton], spontaneity.
He indeed puts these aside as not sufficiently worthy causes
for the order in the universe, [Greek: oud' au tô automatô kai
tê tychê tosouton epitrepsai pragma kalôs eichen]: but he does
not reject them as incapable of producing any effect, but only
as incapable of producing _that_ effect. He himself recognises
[Greek: tychê] and [Greek: to automaton] as co-ordinate agents
with Mind in producing the phenomena of the universe; the
department allotted to them being composed of all the classes
of phenomena which are not supposed to follow any uniform law.
By thus including Chance among efficient causes, Aristotle fell
into an error which philosophy has now outgrown, but which is
by no means so alien to the spirit even of modern speculation
as it may at first sight appear. Up to quite a recent period
philosophers went on ascribing, and many of them have not yet
ceased to ascribe, a real existence to the results of
abstraction. Chance could make out as good a title to that
dignity as many other of the mind's abstract creations: it had
had a name given to it, and why should it not be a reality? As
for [Greek: to automaton], it is recognised even yet as one of
the modes of origination of phenomena, by all those thinkers
who maintain what is called the Freedom of the Will. The same
self-determining power which that doctrine attributes to
volitions, was supposed by the ancients to be possessed also by
some other natural phenomena: a circumstance which throws
considerable light on more than one of the supposed invincible
necessities of belief. I have introduced it here, because this
belief of Aristotle, or rather of the Greek philosophers
generally, is as fatal as the doctrines of Thales and the Ionic
school, to the theory that the human mind is compelled by its
constitution to conceive volition as the origin of all force,
and the efficient cause of all phenomena.[29]

With regard to the modern philosophers (Leibnitz and the
Cartesians) whom I had cited as having maintained that the
action of mind upon matter, so far from being the only
conceivable origin of material phenomena, is itself
inconceivable; the attempt to rebut this argument by asserting
that the mode, not the fact, of the action of mind on matter
was represented as inconceivable, is an abuse of the privilege
of writing confidently about authors without reading them: for
any knowledge whatever of Leibnitz would have taught those who
thus speak of him, that the inconceivability of the mode, and
the impossibility of the thing, were in his mind convertible
expressions. What was his famous Principle of the Sufficient
Reason, the very corner stone of his philosophy, from which the
Preestablished Harmony, the doctrine of Monads, and all the
opinions most characteristic of Leibnitz, were corollaries? It
was, that nothing exists, the existence of which is not capable
of being proved and explained _à priori_; the proof and
explanation in the case of contingent facts being derived from
the nature of their causes; which could not be the causes
unless there was something in their nature showing them to be
capable of producing those particular effects. And this
"something" which accounts for the production of physical
effects, he was able to find in many physical causes, but could
not find it in any finite minds, which therefore he
unhesitatingly asserted to be incapable of producing any
physical effects whatever. "On ne saurait concevoir," he says,
"une action réciproque de la matière et de l'intelligence l'une
sur l'autre," and there is therefore (he contends) no choice
but between the Occasional Causes of the Cartesians, and his
own Preestablished Harmony, according to which there is no more
connexion between our volitions and our muscular actions than
there is between two clocks which are wound up to strike at the
same instant. But he felt no similar difficulty as to physical
causes: and throughout his speculations, as in the passage I
have already cited respecting gravitation, he distinctly
refuses to consider as part of the order of nature any fact
which is not explicable from the nature of its physical cause.

With regard to the Cartesians (not Descartes; I did not make
that mistake, though the reviewer of Dr. Tulloch's Essay
attributes it to me) I take a passage almost at random from
Malebranche, who is the best known of the Cartesians, and,
though not the inventor of the system of Occasional Causes, is
its principal expositor. In Part 2, chap. 3, of his Sixth Book,
having first said that matter cannot have the power of moving
itself, he proceeds to argue that neither can mind have the
power of moving it. "Quand on examine l'idée que l'on a de tous
les esprits finis, on ne voit point de liaison nécessaire entre
leur volonté et le mouvement de quelque corps que ce soit, on
voit au contraire qu'il n'y en a point, et qu'il n'y en peut
avoir;" (there is nothing in the idea of finite mind which can
account for its causing the motion of a body;) "on doit aussi
conclure, si on veut raisonner selon ses lumières, qu'il n'y a
aucun esprit créé qui puisse remuer quelque corps que ce soit
comme cause véritable ou principale, de même que l'on a dit
qu'aucun corps ne se pouvait remuer soi-même:" thus the idea of
Mind is according to him as incompatible as the idea of Matter
with the exercise of active force. But when, he continues, we
consider not a created but a Divine Mind, the case is altered;
for the idea of a Divine Mind includes omnipotence; and the
idea of omnipotence does contain the idea of being able to move
bodies. Thus it is the nature of omnipotence which renders the
motion of bodies even by the divine mind credible or
conceivable, while, so far as depended on the mere nature of
mind, it would have been inconceivable and incredible. If
Malebranche had not believed in an omnipotent being, he would
have held all action of mind on body to be a demonstrated
impossibility.[30]

A doctrine more precisely the reverse of the Volitional theory
of causation cannot well be imagined. The volitional theory is,
that we know by intuition or by direct experience the action of
our own mental volitions on matter; that we may hence infer all
other action upon matter to be that of volition, and might thus
know, without any other evidence, that matter is under the
government of a divine mind. Leibnitz and the Cartesians, on
the contrary, maintain that our volitions do not and cannot act
upon matter, and that it is only the existence of an
all-governing Being, and that Being omnipotent, which can
account for the sequence between our volitions and our bodily
actions. When we consider that each of these two theories,
which, as theories of causation, stand at the opposite extremes
of possible divergence from one another, invokes not only as
its evidence, but as its sole evidence, the absolute
inconceivability of any theory but itself, we are enabled to
measure the worth of this kind of evidence; and when we find
the Volitional theory entirely built upon the assertion that by
our mental constitution we are compelled to recognise our
volitions as efficient causes, and then find other thinkers
maintaining that we know that they are not, and cannot be such
causes, and cannot conceive them to be so, I think we have a
right to say, that this supposed law of our mental constitution
does not exist.

Dr. Tulloch (pp. 45-7) thinks it a sufficient answer to this,
that Leibnitz and the Cartesians were Theists, and believed the
will of God to be an efficient cause. Doubtless they did, and
the Cartesians even believed, though Leibnitz did not, that it
is the only such cause. Dr. Tulloch mistakes the nature of the
question. I was not writing on Theism, as Dr. Tulloch is, but
against a particular theory of causation, which if it be
unfounded, can give no effective support to Theism or to
anything else. I found it asserted that volition is the only
efficient cause, on the ground that no other efficient cause is
conceivable. To this assertion I oppose the instances of
Leibnitz and of the Cartesians, who affirmed with equal
positiveness that volition as an efficient cause is itself not
conceivable, and that omnipotence, which renders all things
conceivable, can alone take away the impossibility. This I
thought, and think, a conclusive answer to the argument on
which this theory of causation avowedly depends. But I
certainly did not imagine that Theism was bound up with that
theory; nor expected to be charged with denying Leibnitz and
the Cartesians to be Theists because I denied that they held
the theory.