In addition to the bare notion of necessary connexion between the cause and its effect, we undoubtedly find in our minds the idea of something resident in the cause which, as we say, produces the effect, and we call this something Force, Power, or Energy. Hume explains Force and Power as the results of the a.s.sociation with inanimate causes of the feelings of endeavour or resistance which we experience, when our bodies give rise to, or resist, motion.

If I throw a ball, I have a sense of effort which ends when the ball leaves my hand; and if I catch a ball, I have a sense of resistance which comes to an end with the quiescence of the ball. In the former case, there is a strong suggestion of something having gone from myself into the ball; in the latter, of something having been received from the ball. Let any one hold a piece of iron near a strong magnet, and the feeling that the magnet endeavours to pull the iron one way in the same manner as he endeavours to pull it in the opposite direction, is very strong.

As Hume says:--

"No animal can put external bodies in motion without the sentiment of a _nisus_, or endeavour; and every animal has a sentiment or feeling from the stroke or blow of an external object that is in motion. These sensations, which are merely animal, and from which we can, _a priori_, draw no inference, we are apt to transfer to inanimate objects, and to suppose that they have some such feelings whenever they transfer or receive motion."--(IV. p. 91, _note_.)

It is obviously, however, an absurdity not less gross than that of supposing the sensation of warmth to exist in a fire, to imagine that the subjective sensation of effort or resistance in ourselves can be present in external objects, when they stand in the relation of causes to other objects.

To the argument, that we have a right to suppose the relation of cause and effect to contain something more than invariable succession, because, when we ourselves act as causes, or in volition, we are conscious of exerting power; Hume replies, that we know nothing of the feeling we call power except as effort or resistance; and that we have not the slightest means of knowing whether it has anything to do with the production of bodily motion or mental changes. And he points out, as Descartes and Spinoza had done before him, that when voluntary motion takes place, that which we will is not the immediate consequence of the act of volition, but something which is separated from it by a long chain of causes and effects. If the will is the cause of the movement of a limb, it can be so only in the sense that the guard who gives the order to go on, is the cause of the transport of a train from one station to another.

"We learn from anatomy, that the immediate object of power in voluntary motion is not the member itself which is moved, but certain muscles and nerves and animal spirits, and perhaps something still more minute and unknown, through which the motion is successively propagated, ere it reach the member itself, whose motion is the immediate object of volition. Can there be a more certain proof that the power by which the whole operation is performed, so far from being directly and fully known by an inward sentiment or consciousness, is to the last degree mysterious and unintelligible? Here the mind wills a certain event: Immediately another event, unknown to ourselves, and totally different from the one intended, is produced: This event produces another equally unknown: Till at last, through a long succession, the desired event is produced."--(IV. p. 78.)

A still stronger argument against ascribing an objective existence to force or power, on the strength of our supposed direct intuition of power in voluntary acts, may be urged from the unquestionable fact, that we do not know, and cannot know, that volition does cause corporeal motion; while there is a great deal to be said in favour of the view that it is no cause, but merely a concomitant of that motion. But the nature of volition will be more fitly considered hereafter.

FOOTNOTE:

[26] Hume, however, expressly includes the "records of our memory" among his matters of fact.--(IV. p. 33.)

CHAPTER VII.

THE ORDER OF NATURE: MIRACLES.

If our beliefs of expectation are based on our beliefs of memory, and antic.i.p.ation is only inverted recollection, it necessarily follows that every belief of expectation implies the belief that the future will have a certain resemblance to the past. From the first hour of experience, onwards, this belief is constantly being verified, until old age is inclined to suspect that experience has nothing new to offer. And when the experience of generation after generation is recorded, and a single book tells us more than Methuselah could have learned, had he spent every waking hour of his thousand years in learning; when apparent disorders are found to be only the recurrent pulses of a slow working order, and the wonder of a year becomes the commonplace of a century; when repeated and minute examination never reveals a break in the chain of causes and effects; and the whole edifice of practical life is built upon our faith in its continuity; the belief that that chain has never been broken and will never be broken, becomes one of the strongest and most justifiable of human convictions. And it must be admitted to be a reasonable request, if we ask those who would have us put faith in the actual occurrence of interruptions of that order, to produce evidence in favour of their view, not only equal, but superior, in weight to that which leads us to adopt ours.

This is the essential argument of Hume's famous disquisition upon miracles; and it may safely be declared to be irrefragable. But it must be admitted that Hume has surrounded the kernel of his essay with a sh.e.l.l of very doubtful value.

The first step in this, as in all other discussions, is to come to a clear understanding as to the meaning of the terms employed.

Argumentation whether miracles are possible, and, if possible, credible, is mere beating the air until the arguers have agreed what they mean by the word "miracles."

Hume, with less than his usual perspicuity, but in accordance with a common practice of believers in the miraculous, defines a miracle as a "violation of the laws of nature," or as "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent."

There must, he says,--

"be an uniform experience against every miraculous event, otherwise the event would not merit that appellation. And as an uniform experience amounts to a proof, there is here a direct and full proof, from the nature of the fact, against the existence of any miracle; nor can such a proof be destroyed or the miracle rendered credible but by an opposite proof which is superior."--(IV. p.

134.)

Every one of these dicta appears to be open to serious objection.

The word "miracle"--_miraculum_,--in its primitive and legitimate sense, simply means something wonderful.

Cicero applies it as readily to the fancies of philosophers, "Portenta et miracula philosophorum somniantium," as we do to the prodigies of priests. And the source of the wonder which a miracle excites is the belief, on the part of those who witness it, that it transcends or contradicts ordinary experience.

The definition of a miracle as a "violation of the laws of nature" is, in reality, an employment of language which, on the face of the matter, cannot be justified. For "nature" means neither more nor less than that which is; the sum of phenomena presented to our experience; the totality of events past, present, and to come. Every event must be taken to be a part of nature, until proof to the contrary is supplied. And such proof is, from the nature of the case, impossible.

Hume asks:--

"Why is it more than probable that all men must die: that lead cannot of itself remain suspended in the air: that fire consumes wood and is extinguished by water; unless it be that these events are found agreeable to the laws of nature, and there is required a violation of those laws, or in other words, a miracle, to prevent them?"--(IV. p. 133.)

But the reply is obvious; not one of these events is "more than probable"; though the probability may reach such a very high degree that, in ordinary language, we are justified in saying that the opposite events are impossible. Calling our often verified experience a "law of nature" adds nothing to its value, nor in the slightest degree increases any probability that it will be verified again, which may arise out of the fact of its frequent verification.

If a piece of lead were to remain suspended of itself, in the air, the occurrence would be a "miracle," in the sense of a wonderful event, indeed; but no one trained in the methods of science would imagine that any law of nature was really violated thereby. He would simply set to work to investigate the conditions under which so highly unexpected an occurrence took place, and thereby enlarge his experience and modify his. .h.i.therto unduly narrow conception of the laws of nature.

The alternative definition, that a miracle is "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent," (IV. p. 134, _note_) is still less defensible.

For a vast number of miracles have professedly been worked, neither by the Deity, nor by any invisible agent; but by Beelzebub and his compeers, or by very visible men.

Moreover, not to repeat what has been said respecting the absurdity of supposing that something which occurs is a transgression of laws, our only knowledge of which is derived from the observation of that which occurs; upon what sort of evidence can we be justified in concluding that a given event is the effect of a particular volition of the Deity, or of the interposition of some invisible (that is unperceivable) agent?

It may be so, but how is the a.s.sertion, that it is so, to be tested? If it be said that the event exceeds the power of natural causes, what can justify such a saying? The day-fly has better grounds for calling a thunderstorm supernatural, than has man, with his experience of an infinitesimal fraction of duration, to say that the most astonishing event that can be imagined is beyond the scope of natural causes.

"Whatever is intelligible and can be distinctly conceived, implies no contradiction, and can never be proved false by any demonstration, argument, or abstract reasoning _a priori_."--(IV.

p. 44.)

So wrote Hume, with perfect justice, in his _Sceptical Doubts_. But a miracle, in the sense of a sudden and complete change in the customary order of nature, is intelligible, can be distinctly conceived, implies no contradiction; and, therefore, according to Hume's own showing, cannot be proved false by any demonstrative argument.

Nevertheless, in diametrical contradiction to his own principles, Hume says elsewhere:--

"It is a miracle that a dead man should come to life: because that has never been observed in any age or country."--(IV. p. 134.)

That is to say, there is an uniform experience against such an event, and therefore, if it occurs, it is a violation of the laws of nature.

Or, to put the argument in its naked absurdity, that which never has happened never can happen, without a violation of the laws of nature. In truth, if a dead man did come to life, the fact would be evidence, not that any law of nature had been violated, but that those laws, even when they express the results of a very long and uniform experience, are necessarily based on incomplete knowledge, and are to be held only as grounds of more or less justifiable expectation.

To sum up, the definition of a miracle as a suspension or a contravention of the order of Nature is self-contradictory, because all we know of the order of nature is derived from our observation of the course of events of which the so-called miracle is a part. On the other hand, no event is too extraordinary to be impossible; and, therefore, if by the term miracles we mean only "extremely wonderful events," there can be no just ground for denying the possibility of their occurrence.

But when we turn from the question of the possibility of miracles, however they may be defined, in the abstract, to that respecting the grounds upon which we are justified in believing any particular miracle, Hume's arguments have a very different value, for they resolve themselves into a simple statement of the dictates of common sense--which may be expressed in this canon: the more a statement of fact conflicts with previous experience, the more complete must be the evidence which is to justify us in believing it. It is upon this principle that every one carries on the business of common life. If a man tells me he saw a piebald horse in Piccadilly, I believe him without hesitation. The thing itself is likely enough, and there is no imaginable motive for his deceiving me. But if the same person tells me he observed a zebra there, I might hesitate a little about accepting his testimony, unless I were well satisfied, not only as to his previous acquaintance with zebras, but as to his powers and opportunities of observation in the present case. If, however, my informant a.s.sured me that he beheld a centaur trotting down that famous thoroughfare, I should emphatically decline to credit his statement; and this even if he were the most saintly of men and ready to suffer martyrdom in support of his belief. In such a case, I could, of course, entertain no doubt of the good faith of the witness; it would be only his competency, which unfortunately has very little to do with good faith or intensity of conviction, which I should presume to call in question.

Indeed, I hardly know what testimony would satisfy me of the existence of a live centaur. To put an extreme case, suppose the late Johannes Muller, of Berlin, the greatest anatomist and physiologist among my contemporaries, had barely affirmed he had seen a live centaur, I should certainly have been staggered by the weight of an a.s.sertion coming from such an authority. But I could have got no further than a suspension of judgment. For, on the whole, it would have been more probable that even he had fallen into some error of interpretation of the facts which came under his observation, than that such an animal as a centaur really existed. And nothing short of a careful monograph, by a highly competent investigator, accompanied by figures and measurements of all the most important parts of a centaur, put forth under circ.u.mstances which could leave no doubt that falsification or misinterpretation would meet with immediate exposure, could possibly enable a man of science to feel that he acted conscientiously, in expressing his belief in the existence of a centaur on the evidence of testimony.

This hesitation about admitting the existence of such an animal as a centaur, be it observed, does not deserve reproach, as scepticism, but moderate praise, as mere scientific good faith. It need not imply, and it does not, so far as I am concerned, any _a priori_ hypothesis that a centaur is an impossible animal; or, that his existence, if he did exist, would violate the laws of nature. Indubitably, the organisation of a centaur presents a variety of practical difficulties to an anatomist and physiologist; and a good many of those generalisations of our present experience, which we are pleased to call laws of nature, would be upset by the appearance of such an animal, so that we should have to frame new laws to cover our extended experience. Every wise man will admit that the possibilities of nature are infinite, and include centaurs; but he will not the less feel it his duty to hold fast, for the present, by the dictum of Lucretius, "Nam certe ex vivo Centauri non fit imago," and to cast the entire burthen of proof, that centaurs exist, on the shoulders of those who ask him to believe the statement.

Judged by the canons either of common sense, or of science, which are indeed one and the same, all "miracles" are centaurs, or they would not be miracles; and men of sense and science will deal with them on the same principles. No one who wishes to keep well within the limits of that which he has a right to a.s.sert will affirm that it is impossible that the sun and moon should ever have been made to appear to stand still in the valley of Ajalon; or that the walls of a city should have fallen down at a trumpet blast; or that water was turned into wine; because such events are contrary to uniform experience and violate laws of nature. For aught he can prove to the contrary, such events may appear in the order of nature to-morrow. But common sense and common honesty alike oblige him to demand from those who would have him believe in the actual occurrence of such events, evidence of a cogency proportionate to their departure from probability; evidence at least as strong as that, which the man who says he has seen a centaur is bound to produce, unless he is content to be thought either more than credulous or less than honest.

But are there any miracles on record, the evidence for which fulfils the plain and simple requirements alike of elementary logic and of elementary morality?

Hume answers this question without the smallest hesitation, and with all the authority of a historical specialist:--

"There is not to be found, in all history, any miracle attested by a sufficient number of men, of such unquestioned goodness, education, and learning, as to secure us against all delusion in themselves; of such undoubted integrity, as to place them beyond all suspicion of any design to deceive others; of such credit and reputation in the eyes of mankind, as to have a great deal to lose in case of their being detected in any falsehood; and at the same time attesting facts, performed in such a public manner, and in so celebrated a part of the world, as to render the detection unavoidable: All which circ.u.mstances are requisite to give us a full a.s.surance of the testimony of men."--(IV. p. 135.)

These are grave a.s.sertions, but they are least likely to be challenged by those who have made it their business to weigh evidence and to give their decision under a due sense of the moral responsibility which they incur in so doing.

It is probable that few persons who proclaim their belief in miracles have considered what would be necessary to justify that belief in the case of a professed modern miracle-worker. Suppose, for example, it is affirmed that A.B. died and that C.D. brought him to life again. Let it be granted that A.B. and C.D. are persons of unimpeachable honour and veracity; that C.D. is the next heir to A.B.'s estate, and therefore had a strong motive for not bringing him to life again; and that all A.B.'s relations, respectable persons who bore him a strong affection, or had otherwise an interest in his being alive, declared that they saw him die. Furthermore, let A.B. be seen after his recovery by all his friends and neighbours, and let his and their depositions, that he is now alive, be taken down before a magistrate of known integrity and acuteness: would all this const.i.tute even presumptive evidence that C.D. had worked a miracle? Unquestionably not. For the most important link in the whole chain of evidence is wanting, and that is the proof that A.B. was really dead. The evidence of ordinary observers on such a point as this is absolutely worthless. And, even medical evidence, unless the physician is a person of unusual knowledge and skill, may have little more value.

Unless careful thermometric observation proves that the temperature has sunk below a certain point; unless the cadaveric stiffening of the muscles has become well established; all the ordinary signs of death may be fallacious, and the intervention of C.D. may have had no more to do with A.B.'s restoration to life than any other fortuitously coincident event.

It may be said that such a coincidence would be more wonderful than the miracle itself. Nevertheless history acquaints us with coincidences as marvellous.