On Mans Instinctive Belief in the Constancy of Nature.
1. When a child strikes a table for the first time with a
spoon, its delight in the consequent noise is not more obvious, than the
confidence wherewith it anticipates a repetition of the noise on a repetition
of the stroke. That the same antecedent should be followed by the same
consequent does not appear to be the lesson of a protracted experience. The
anticipation of a similar result from a similar conjunction of circumstances
appears to be as strong in infancy as in manhood. We hold it to be not an
acquired but an original faith, because we perceive it in full operation as far
back as we can observe in the history of a human creature. We are not sensible
of a period in the history of our own mind when this lesson had yet to be
learned - neither can we perceive any indication in the youngest children, that
they are destitute of this faith, or that they have yet subsequently to acquire
it. Therefore we call it an instinctive faith - not the fruit of observation or
experience, however much these may afterwards confirm it; so as to verify the
glorious coclueion of an unfailing harmony between the actual truth of things,
and the implanted tendencies of that intellect which the Creator hath given us.
2. It. is a frequent and perhaps a natural impression that faith in the constancy of nature is not an instinct antecedent to experience, but the fruit of that experience, produced by it at first, and strengthened by every new or repeated experience of the constancy of nature afterwards. But it has been well remarked by Dr. Brown, that no repetition however frequent of the same sequence can account for our anticipation of its recurrence, without such an original principle of belief as we are now contending for. We admit that there is no logical connexion between the proposition that a certain event has happened once in given circumstances, and the proposition that the same event will happen always in the same circumstances. But neither is there any logical connexion between the proposition that the event has happened a thousand times in certain circumstances, and the proposition that in the same circumstances it will always so happen. The conversion of the past into the future, is made, not in virtue of a logical inference; but in virtue of an instinctive expectation and this at whatever stage the conversion may have been made. It is as confidently made at the dawn as at the maturity of the understanding - . and after one observation of a sequence, as after twenty or any number of observations however great. We have not been schooled by experience into our belief of natures constancy. Experience can only inform us of the past. It tells what has been - but we need another informant beside memory to assure us of what is to be. Experience tells us of the past constancy of nature - but experience alone or memory alone can give no intimation of its future constancy. This irresistible persuasion comes to us from another quarter. It forms a distinct principle in the frame or workmanship of our intellectual system. It is a befitting theme of gratitude and wonder that this instinctive faith from within, should be responded to by the unexcepted fulfilment of Natures actual and abiding constancy from without. But the one is not a derivative from the other. The two are in harmony - but it is a contingent harmony.
3. The use of experience is not to strengthen our faith in the constancy of Natures sequences - but to inform us what the sequences actually are. We do not need to be made surer than we are already that the progressions of Nature are invariable - but we need to learn the steps of each progression. As far as we can discover of the human mind, it counts, and has at all times from its earliest capacities of thought, counted on the same antecedents being followed up by the same consequents. It is not the office of experience to lesson us into this confidence. But experience is indispensable to teach us, which be the causal antecedents and which be the consequents related to them by the tie of invariableness, in those successions that are taking place around us. Our object on the repetition of an experiment is not to be made sure that what Nature has done once in certain circumstances, she will in the same circumstances do again. But it is to ascertain what the circumstances really be which are essential to the result in question. The truth is, that in that assemblage of circumstances which precedes some certain event, there may only be one or so many of them that have causal influence upon the result, and the rest may be mere accompaniments whose presence is not necessary to the production of it. It is to distinguish the causal antecedents from the merely casual ones, that an experiment has often to be varied or done over again. It is not that we ever have the least suspicion of Nature as if she fluctuated in her processes. But it is to disentangle these processes from that crowd of accessaries, wherewith they are at times beset or encompassed, that we have so repeatedly to question her. For this purpose we withdraw certain ingredients from the assemblage. We supply certain others. We mix them up in various proportions - and all this, not to strengthen our belief in the regularity of Nature - but to discover what the trains or successions are, according to which this regularity proceeds. We are not sure that the instinct by which we are led to anticipate the same result in the same circumstances is stronger in manhood than in infancy. But in manhood we know the result and we know the circumstances. This seems the whole fruit of experience. It teaches not the strength or invariableness of the connexion, that runs through all nature - but it teaches the terms of that connexion.
4. And it is instructive to observe the real process of an infants mind, during that education by which it becomes acquainted with surrounding nature. When it strikes the wooden table with a spoon, it needs not repeat the stroke for the purpose of obtaining a surer or firmer expectation of the consequent noise. That expectation is probably as confident at the first as afterward - and it is of importance to remark, that at the outset of its experience it is quite general and indiscriminate. For instance, it would anticipate the same noise by striking the spoon against any surface whatever, as when placed on a carpet, or on the level of a smooth sandy beach. Originally it would expect the same noise by striking on a soft yielding substance that it did by striking on the hard table - and the office of experience is not to strengthen its hope of a similar result from a similar act, but in truth to correct the exuberance of that hope. It is to teach it discrimination - and how in the midst of a general resemblance, to mark those minuter differences which in fact present it with antecedents that are really different, and which should lead it to expect results that are different also. It is thus that the primary undirected and diffused expectation, of meeting again with what it met once in the act of striking with a spoon on a wooden surface, comes afterwards to be modified. It learns - not that there is a surer tie between the terms of natures sequences than it imagined at the first - but it learns how to distinguish between the terms which are really different, though before it had vaguely confounded them. And so it is taught with each distinct antecedent to look for a distinct consequent instead of expecting the same noise by the infliction of a stroke upon all surfaces, to expect no noise at all by a stroke upon the sand, and different sorts of noises by a stroke on different surfaces, whether wood or metal or stone or liquid.
5. Now this may explain how it is, that our faith in the constancy of nature appears to grow with experience and that, notwithstanding the obvious strength of this principle in very early childhood. After an infant has once struck the table with a spoon and elicited the noise which it likes, it proceeds with all confidence to repeat the stroke - not on the table only, but on other substances, in expectation of a similar noise to that which had pleased and gratified it before. But it is speedily checked in this expectation. It learns that with every difference in the antecedent circumstances, there may be a difference in the result - and it further learns that there may often be real differences which escape its observation. Now the longer it has been accustomed to witness the same phenomenon in the same ostensible circumstances, it becomes the more confident that these are the only essential circumstances to the result, or at least that the ostensible circumstances always involve the essential or the real ones. Should it awake in the morning, and perceive the nurse or mother by its side and smiling over it - then were there but a moment of prior consciousness, and the recollection of what had happened yesterday, it might on the next morning open its eyes with expectation of being again regaled by the same spectacle.
We are not sure, but that the confidence of this expectation would be as strong, if not stronger at the first than ever afterwards. Every disappointment in fact would weaken it- for the infant would thus learn that the presence of the causal antecedent, which gave rise to the phenomenon, was not always involved in the circumstance of its emerging from the darkness of sleep to the visible objects of day. Still it holds true that the fewer the disappointments were to which it was exposed, the original confidence would be less weakened. The recurrence of the same thing for the days of a week would diminish its apprehension of a disappointment or failure - and still more for the days of a month or the days of a year. Yet we are not sure, if any experience, however lengthened, would ever beget a stronger confidence than that original and unshaken confidence that is felt prior to all experience. It seems the primary faith of every mind that there shall be a constant recurrence of the same effect in the same circumstances. It is a subsequent lesson to this that the circurnstances are liable to unexpected variation - and so a protracted experience may be requisite to ascertain when they are more and when they are less liable, or whether they have sustained variation at all. Still even in cases where the last conclusion has been come at, and with the advantage of a long experience in its favour, the resulting anticipation may not be of greater strength than was that original, anticipation wherewith the infant looked for a repetition of the sound from its first repetition of a stroke. This long experience does not act as a confirmer to strengthen the first anticipation. It only acts as a restorative against the weakening effect of a subsequent experience; and by which it may, as if by the removal of a disturbing force, bring the confidence, not beyond, but bring it up to the strength which it originally had.
6. It will thus be seen what the precise object is, of repetition in experiments. It is not to strengthen our faith in the uniformity of Nature. It is not to assure ourselves any more than we are already that the same antecedents will always be followed up by the same consequents. It is to ascertain what the precise causal antecedents actually are. For this purpose we introduce variations into the circumstances of the experiment. We supply new conditions. We abstract old ones. We make changes both on the presence and the proportion of certain ingredients - and thus learn to distinguish what is merely accessary from what is efficient in the process. We come to fix on the real and proper antecedents at last-and when in an experimentunt crucis, these are admitted and no other, we decide finally that they and they alone are essential to the result in question.
7. Experience does not add to the confidence wherewith we look for the same result in the same circumstances. It may rather be said to correct or to modify that confidence. It teaches us how liable we are to be deceived by semblances; and that often there is an apparent similarity where there is no real one. In this case, when counting on a recurrence of the same, the presumption is thwarted by the occurrence of a different event. Instead of confidence we in certain views learn caution and distrust at the school of experience - not that we ever question the invariableness wherewith the same antecedents are always related to the same consequents - but that we have learned how under the guise of similarity there may not be sameness; and that in virtue of some unseen difference in the circumstances, an unexpected difference in the result may arise from it.
8. But it is well for our future argument to distinguish what the confidence is which is lessened from what the confidence is which remains unshaken. The childs general confidence in the production of a noise by the stroke of its spoon on any surface has been thwarted and put an end to - but its special confidence in the production of a noise by the stroke, of the spoon on its own wooden table continues as strong as at the first. There is no mistake in that original and instinctive faith of nature, by which we are led to expect that the same antecedents will be followed in invariable succession by the same consequents and it is not this which is corrected by experience. But we are liable to a perpetual mistake, in confounding together as the same those antecedents which are really differentand it is the office of experience to correct this mistake, by teaching us so to discriminate as to distinguish betweeu the things which are really different. There is a beautiful accordance between our primary instincts of belief, and the lessons of our ultimate experience. We set out strong in the presumption of Natures uniformity; and in this we are disappointed at the first-only because we mistake Nature, and confound when we ought to discriminate. In proportion as we learn to discriminate, the confidence is restored - and we find it was no mistake that Nature proceeded by trains of invariable phenomena, and that the only fallacy lay in our mistaking and misreading the phenomena themselves. It is thus that in the further progress of experience the temporary cloud is dissipated; and it at once appears that every process is steadfast, and that every instinct is sure - that Nature puts no deceitful expectation, and whispers no false promises into the hearts of her children.
9. Let us now reassemble the different leading phenomena of mans belief in the constancy of Nature. He in the first instance is furnished with this belief and feels it strongly, antecedently to experience. In the second instance, the experience does not add any further assurance to this primary and instinctive faith. It rather seems to check its anticipations, insomuch that distrust rather than confidence in the results of experience seems to be the growth of our advancing observation. But this proceeds not from Nature being untrue to her promise, which in the shape of an original instinct she makes to all men, of always following up the same antecedents by the same consequents. It proceeds from our imperfect observation, whether of the antecedents or consequents, by which we imagine them to be the same when they are really different. In proportion as this imperfect observation is rectified, the steadfastness of Nature becomes more manifest. The promise which she made to us at the outset is more and more vindieated - and we at length are fully reassured of an unexcepted harmony between the instincts of our internal constitution and the external truth of things.
10. We may thus perceive the consistency between two propositions which appear to be at variance. The first is that experience gives no addition of strength to our primary Faith in the constancy of Nature. The second is that the oftener we witness the same result in the same apparent circumstances, the more confidently do we look for that result in these circumstances in all time coming. It is not that we ever doubt the constancy of Nature. The doubt is, whether the same causal antecedents which give rise to the result be always involved in the same apparent circumstances. Should the same individual regularly pass my window every day at the same hour for a. month together, I by the end of that time should have acquired a pretty strong persuasion that at the wonted hour he would again make his appearance. It is obvious that this persuasion would become stronger with every new repetition of the phenomenon, till at length I might come to regularly count upon it with a very high feeling of prqbability upon its side. And yet in this instance, I may not at all know the causal antecedents of the appearances in question. There might be nothing at least in the ostensible antecedents to indicate the causal or real ones - nothing in the mere occurrence of the hour which can explain to me, why it is that this one person so regularly presents himself. It is enough however to find that so it is-and the longer or the oftener that so it is, - the firmer will be my expectation of its recurrence. The expectation will according to the various instances attain to various degrees of strength - and in some will reach indefinitely near to moral certainty.
11. The same thing will happen, if in throwing a couple of dice, for a number of times there shall be. the regular presentation of the same faces in both. of them. The expectation of the phenomenon will gain in strength just with the continuance of it - and that, anterior to our knowledge of its cause. Even previous to this knowledge it might approach to moral certainty, merely by the length and constancy of the repetition. - Yet no experience however prolonged will give a stronger assurance than we might have had at once by observing that the dice was loaded, and thus obtaining knowledge of the real antecedent.
12. There are cases when without the knowledge, or at least without any reflection on the cause, this constancy of a recurrence will lead us to look for it with all the confidence of moral certainty. The return of the mornings light, and the recurrence of about two tides every day are the examples of this which first occur to us. The causal antecedent of the former phenomenon may not be reflected on, and of the latter may not be known. Yet thing does not affect the confidence wherewith we look forward to the repetition of them. It is a confidence which evidently grows with the number of repetitions provided that these have occurred with undeviating constancy. Yet we are not sure if the unvarying experience of a whole lifetime will give a stronger assurance, than that wherewith a child expects the recurrence of a noise by striking its spoon upon the table after having heard it but once, or even by striking it upon any other surface before that experience had taught it to distinguish between that which is sonorous and that which is not so. The strength then of the primary confidence on the part of the child, and that of the acquired confidence on the part of the man, will be found to have originated in distinct causes. The former is anterior to experience, and an instinct of the understanding, by which, from the earliest dawn of thought, we feel assured that the same antecedents will always be followed up by the same consequents. The latter again is the fruit or the lesson. of experience; and the effect, it should be remarked, is not to build up a confidence that is already perfect. That the same antecedents will be followed by the same consequents is a truth whereof we have the axiomatic certainty from the beginning of life to the close of it. But we often mistake the antecedents, thinking them to be the same when they are really different - and it is the office of experience to rectify this mistake. We may even never come to know the efficient antecedents at all, as in the case of the unlearned who are conversant with phenomena but have not so much as a thought about the causes of them, save that, in the circumstances by which these phenomena are wont to be preceded, their causes must be present or be somehow involved in them. The darkness of night is not the cause of the light of day - but they have learned by frequent observation, that, at the expiry of a certain period of darkness, the cause of this light comes into operation. Experience does not tell that the same cause always produces the same effect. This we had been told previously. But experience tells what the circumstances are in which the same cause is to be met with- and the oftener we so meet with it, the greater is our confidence that in the same circumstances we shall meet with it and with its invariable consequent again. These two tellings are wholly distinct from each other. By the first we are assured of the invariable operation of causes. By the second we learn in what assemblage of circumstances the same causes are seldomer or oftener or always to be found. In regard to the first there is the utmost strength of anticipation from the outset of our mental history. In regard to the second there is a growing strength of anticipation which approaches indefinitely towards a full assurance.
13. That is well nigh to a full assurance wherewith we anticipate a high-water about every twelve hours. We can conceive this assurance to be disappointed. It is an imaginable case that there might have been the intermission of one tide giving rise to an interval of somewhat more than twenty-four hours between two high-waters. Let us suppose the sea at its lowest ebb, at the very time when, according to the rate and regularity of all past experience, there should have been an intermediate high-water. The question is on what evidence ought this to be believed ? - or what force and character of proof can prevail over that confident expectation, which, on the strength of an observed constancy during all the years of our recollection, we had been led to form?
14.We shall not at present oppose to the strength of this expectation either the evidence of sense or the evidence of testimony. But there is a certain device of illustration which we shall employ, as being the most effectual preparative that we can think of for the evolving of our main argument.
15. Instead then of having the evidence of sense for this anomalous low-water - we can imagine the observer placed at a distance from the sea - and furnished with his information of every rise and fall in its level by means of a tide-index. The reality or the possibility of such an instrument is not essential to the validity of our argument. An hypothetical reasoning may not be the less sound, because of its imaginary data - and, if we can demonstrate a perfect analogy between these data and others which are real, between the arbitrary conditions which we find it convenient in the first instance to assume and the actual conditions of the question that waits to be resolved, then, by a substitution of the one for the other, we may arrive at the solution that is wanted.
16.We may conceive then that on the day of the anomalous low-water, the tide-index also remained low. To set aside all but my own personal experience in the matter, there might have been a thousand instances of observed regu]arity on my part, in regard to the occurrence of high-water - in which case the probability against the occurrence of an anomalous low-water would be as a thousand to one. It may further be conceived that though on all the other thousand occasions, I observed a perfect harmony between the phenomena of high and low-water and the indications of the instrument - yet that on one occasion the instrument deceived me - it having anomalously stood at low-water though there was high-water on the sea as usual. In this case my expectation of a high-water grounded on past experience will prevail over my faith in the information of the tide-index. The truth is that against the actual occurrence of the anomalous low-water, the probability is as a thousand to one - whereas against a wrong deposition on the part of the instrument the probability is only as a thousand to two. There is a double chance for an irregularity on the part of the instrument, rather than an irregularity on the part of the ocean - and I am therefore not yet dislodged from my belief that though the instrument did attest a low-water, the high-water took place as usual.
17. One can imagine a still greater degree of irregularity on the part of the tide-index. The number of failures (including the case in question) may have been five or ten or twenty or fifty - in which case the chances of error in the information given would just be represented by these respective numbers and I would persist in my conviction of there having been a highwater with a strength equal in the first case to that of two to one, in the second of five to one, in the third of ten to one, in the fourth of twenty to one, and in the fifth with a strength equal to that of fifty to one.
18. But we can imagine an instrument that never misgave or made a false indication in the whole course of our experience. We may have observed the stated recurrence of a high-water at the usual interval a thousand times, and as many times, we may have without fail observed the rise in the tide-index which corresponds thereunto. That a low-water should occur instead of the next expected highwater is a thing improbable in the ratio of a thousand to one. That the high-water should occur and yet the index point to a low-water is also a thing improbable, and in the same ratio of a thousand to one. The one improbability exactly balances or neutralizes the other. The mind is left in in a midway state or in a state of pure scepticism on the question-and it remains to be seen whether it is possible by means of any accession to the testimony of these tide-indices, to arrive at a legitimate belief in the occurrence of an anomalous low-water; or, to express it otherwise, belief in the violation of a wonted order to which we never had witnessed a single exception in the whole of our past experience.
19. It may be conceived in this way. The same instrument which set in a particular way so relates it to the water of the sea as to indicate the variations of its level, may be so set as to relate it similarly to other water of variable level, as to that of a pond or a well or a vessel, the liquid in all which was subject to alternate elevations and depressions. We have already made the supposition of having observed the unfailing punctuality of its informations in regard to the tides - so as to establish the probability of a thousand to one in favour of that information being true. But should it inform us of a low-water at the time when, on the strength of a thousand past instances, we were left to expect a high-water the probability for the truth of this information is exactly countervailed by an equal probability opposed to it. By applying the same instrument however to the measurement of other fluctuations in the level of water beside those of the sea, the samples of its correct indication may be multiplied indefinitely. - , and instead of a thousand observed instances in which it spoke the truth, we may in virtue of this larger application be able to allege twenty thousand. After this it remains no longer a contest of. equal experiences, but of unequal - and the difference is all in favour of the witnessing instrument. If it depone to a matter against which, apart from its own information, there is the probability of a thousand to one, it should now be recollected that in the verity of this information there is a probability of twenty thousand to one. Or in other words we have a probability of twenty to one for the anomalous low-water. So that with the evidence of one instrument alone, the violation of a long observed order may be abundantly established; and it is a possible thing that the experience which stands opposed to the testimony of this solitary witness may, singly in the witness itself, be greatly surpassed by the experience in its favour.
20. Or the accession to the evidence of the tide - index may be obtained in another way. Instead of widening the range of its application, so as to collect twenty thousand instances of its accuracy wherewith to overbear the thousand instances of regular high-water, the very same power and superiority of evidence could be had by means of another tide-index. We have supposed a number of these instruments which, either from their various mechanisms, or from their being constructed with more or less skill, gave forth their depositions with more or less accuracy. Let us compute the effect then which lies in the concurrence of two testimonies to the fact of an anomalous low-water - one given by a tide-index of yet unfailing correctness, and another which in the thousand instances of regular high-water failed no less than fifty times. Still it has been twenty times right for once being wrong; and the presumption in favour of its testimony for any indifferent thing is just as twenty to onethough in favour of its testimony for an anomalous low-water in the face of a thousand regular high-waters it be only as one to fifty. This however does not prevent the multiple effect of its evidence when united with that of another instrument. This tide-index which has been right without exception in a thousand instances, has acquired the probability of a thousand to one for its next deposition - and, should the other instrument which has been right twenty times for one, agree in the same deposition, the united testimony of both, has precisely the force of twenty thousand to, one for any indifferent thing and in the present case of twenty to one for an anomalous low water. There is no one versant in the doctrine of probabilities who will dispute the soundness or accuracy of these conclusions -a doctrine not only of mathematical precision in the abstract - but whose precision is verified on the average in all the practical affairs of experience and human life. The probability arising from the concurrence of the two testimonies which we have now specified is just as we have stated it. And to vary the supposition - should the tide-index which has failed ten times in a thousand, agree in its evidence with the tide-index that has failed twenty times - still the former has only been wrong once in a hundred times and the other once in fifty so that their united testimony has in it the strength of five thousand to one for an indifferent thing and five to one for an anomalous low-water. It were easy to calculate the results in all other instances of agreement. The joint testimony of the tide-gauge that has failed five times with that which has failed fifty times has in it the absolute force of four thousand to one, or the relative force of four to one for an anomalous low-water. The joint effect of the one that has failed five times with the one that has failed ten is equivalent to twenty in favour of the same fact - and should the evidence of the one that has failed twenty times be added to the two former, the testimony of all the three would have the force of no less than a million to one for any indifferent thing, or of a thousand to one for the anomalous deviation which is the subject of our argument.
21. On the subject of the amount of evidence that lies in the concurrence of two or more such notices as we are now specifying, it must be observed that these notices should be independent of each other. For example, when the tide-index B announces a low-water, it must not be because the tide-index A announces the same thing. Each by being similarly related to the waters of the sea is subject to a common influence from it - but neither should have any influence the one upon the other. It is easy to perceive that in the present instance they stand so disjoined, as to give us the advantage of all the united strength that lies in separate and independent testimonies. It is not because A gives a right deposition that B gives the same. B is sometimes wrong when A is right - and beside each would operate precisely as it does though the other were removed or taken down.
22. By the concurrence of independent notices on the subject, the amount of evidence for an anomalous low-water may become indefinitely great. There may be other tide-indices, and that too of the best sort, in other houses beside our own - and each of which has never been known to present a false indication in the whole course of human experience. The concurrent testimony of two such instruments yields the probability of a thousand - of three no less than a million - till the number of distinct and independent testimonies be so great as to make the superiority of evidence quite overwhelming, and to afford practically the force of an absolute moral certainty on the side of an anomalous low-water. Or, instead of an anomalous if it be called a miraculous low-water - this is only lengthening out the experience that we have had of Natures regularity in this department of observation. Instead of one deviation in a thousand instances of observed constancy, the event, in question may be the only deviation that has taken place in the regular succession of tides since the commencement of the world. To meet this we have just to imagine a tide-index that was never known to give forth a false intimation; and to overmatch this, we have just to imagine so many distinct and separate intimations from a certain number of such indices. The falsity of the instrument may be as great an anomaly or if you will as great a miracle as the phenomenon of which it tells - and the concurrence of a few such miracles may establish for the truth of the miracle deponed to as overwhelming a superiority of evidence as before. It remains to be seen how much or how little can be done in this way by living witnesses but it seems very clear to us on the strength of the above reasoning, that at the mouth of two or three inanimate witnesses the truth of a miracle may be established.
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