Chapter VIII: Inference (3)

A learned writer says, “In criminal prosecutions, the circumstantial evidence should be such, as to produce nearly the same degree of certainty as that which arises from direct testimony, and to exclude a rational probability of innocence.(24)” By degrees of certainty he seems to mean, together with many other writers, degrees of proof, or approximations towards proof, and not certitude, as a state of mind; and he says that no one should be pronounced guilty on evidence which is not equivalent in weight to direct testimony. So far is clear; but what is meant by the expression “_rational_ probability”? for there can be no probability but what is rational. I consider that the “exclusion of a rational probability” means “the exclusion of any argument in the man’s favour which has a rational claim to be called probable,” or rather, “the rational exclusion of any supposition that he is innocent;” and “rational” is used in contradistinction to argumentative, and means “resting on implicit reasons,” such as we feel, indeed, but which for some cause or other, because they are too subtle or too circuitous, we cannot put into words so as to satisfy logic. If this is a correct account of his meaning, he says that the evidence against a criminal, in order to be decisive of his guilt, to the satisfaction of our conscience, must bear with it, along with the palpable arguments for that guilt, such a reasonableness, or body of implicit reasons for it in addition, as may exclude any probability, really such, that he is not guilty,—that is, it must be an evidence free from anything obscure, suspicious, unnatural, or defective, such as (in the judgment of a prudent man) to hinder that summation or coalescence of the evidence into a proof, which I have compared to the running into a limit, in the case of mathematical ratios. Just as an algebraical series may be of a nature never to terminate or admit of valuation, as being the equivalent of an irrational quantity or surd, so there may be some grave imperfections in a body of reasons, explicit or implicit, which is directed to a proof, sufficient to interfere with its successful issue or resolution, and to balk us with an irrational, that is, an indeterminate, conclusion.

So much as to the principle of conclusions made upon evidence in criminal cases; now let us turn to an instance of its application in a particular instance. Some years ago there was a murder committed, which unusually agitated the popular mind, and the evidence against the culprit was necessarily circumstantial. At the trial the Judge, in addressing the Jury, instructed them on the kind of evidence necessary for a verdict of _guilty_. Of course he could not mean to say that they must convict a man, of whose guilt they were not certain, especially in a case in which two foreign countries, Germany and the American States, were attentively looking on. If the Jury had any doubt, that is, reasonable doubt, about the man’s guilt, of course they would give him the benefit of that doubt. Nor could the certitude, which would be necessary for an adverse verdict, be merely that which is sometimes called a “practical certitude,” that is, a certitude indeed, but a certitude that it was a “duty,” “expedient,” “safe,” to bring in a verdict of guilty. Of course the Judge spoke of what is called a “speculative certitude,” that is, a certitude of the fact that the man was guilty; the only question being, what evidence was sufficient for the proof, for the certitude of that fact. This is what the Judge meant; and these are among the remarks which, with this drift, he made upon the occasion:—

After observing that by circumstantial evidence he meant a case in which “the facts do not directly prove the actual crime, but lead to the conclusion that the prisoner committed that crime,” he went on to disclaim the suggestion, made by counsel in the case, that the Jury could not pronounce a verdict of _guilty_, unless they were as much satisfied that the prisoner did the deed as if they had seen him commit it. “That is not the certainty,” he said, “which is required of you to discharge your duty to the prisoner, whose safety is in your hands.” Then he stated what was the “degree of certainty,” that is, of certainty or perfection of proof, which was necessary to the question, “involving as it did the life of the prisoner at the bar,”—it was such as that “with which,” he said, “you decide upon and conclude your own most important transactions in life. Take the facts which are proved before you, separate those you believe from those which you do not believe, and all the conclusions that naturally and almost necessarily result from those facts, you may confide in as much as in the facts themselves. The case on the part of the prosecution is the _story_ of the murder, told by the _different_ witnesses, who _unfold the circumstances one after another_, according to their occurrence, together with the _gradual_ discovery of some apparent connexion between the property that was lost, and the possession of it by the prisoner.”

Now here I observe, that whereas the conclusion which is contemplated by the Judge, is what may be pronounced (on the whole, and considering all things, and judging reasonably) a proved or certain conclusion, that is, a conclusion of the truth of the allegation against the prisoner, or of the fact of his guilt, on the other hand, the _motiva_ constituting this reasonable, rational proof, and this satisfactory certitude, needed not, according to him, to be stronger than those on which we prudently act on matters of important interest to ourselves, that is, probable reasons viewed in their convergence and combination. And whereas the certitude is viewed by the Judge as following on converging probabilities, which constitute a real, though only a reasonable, not an argumentative, proof, so it will be observed in this particular instance, that, in illustration of the general doctrine which I have laid down, the process is one of “line upon line, and letter upon letter,” of various details accumulating and of deductions fitting in to each other; for, in the Judge’s words, there was a story—and that not told right out and by one witness, but taken up and handed on from witness to witness—gradually unfolded, and tending to a proof, which of course might have been ten times stronger than it was, but was still a proof for all that, and sufficient for its conclusion,—just as we see that two straight lines are meeting, and are certain they will meet at a given distance, though we do not actually see the junction.

3. The third instance I will take is one of a literary character, the divination of the authorship of a certain anonymous publication, as suggested mainly by internal evidence, as I find it in a critique written some twenty years ago. In the extract which I make from it, we may observe the same steady march of a proof towards a conclusion, which is (as it were) out of sight;—a reckoning, or a reasonable judgment, that the conclusion really is proved, and a personal certitude upon that judgment, joined with a confession that a logical argument could not well be made out for it, and that the various details in which the proof consisted were in no small measure implicit and impalpable.

“Rumour speaks uniformly and clearly enough in attributing it to the pen of a particular individual. Nor, although a cursory reader might well skim the book without finding in it anything to suggest, &c., ... will it appear improbable to the more attentive student of its internal evidence; and the improbability will decrease more and more, in proportion as the _reader is capable_ of judging and appreciating the _delicate, and at first invisible touches_, which limit, to _those who understand them_, the individuals who can have written it to a very small number indeed. The utmost scepticism as to its authorship (_which we do not feel ourselves_) cannot remove it farther from him than to that of some one among his most intimate friends; so that, leaving others to discuss antecedent probabilities,” &c.

Here is a writer who professes to have no doubt at all about the authorship of a book,—which at the same time he cannot prove by mere argumentation set down in words. The reasons of his conviction are too delicate, too intricate; nay, they are in part invisible; invisible, except to those who from circumstances have an intellectual perception of what does not appear to the many. They are personal to the individual. This again is an instance, distinctly set before us, of the particular mode in which the mind progresses in concrete matter, viz. from merely probable antecedents to the sufficient proof of a fact or a truth, and, after the proof, to an act of certitude about it.

I trust the foregoing remarks may not deserve the blame of a needless refinement. I have thought it incumbent on me to illustrate the intellectual process by which we pass from conditional inference to unconditional assent; and I have had only the alternative of lying under the imputation of a paradox or of a subtlety.

§ 3. Natural Inference.

I commenced my remarks upon Inference by saying that reasoning ordinarily shows as a simple act, not as a process, as if there were no medium interposed between antecedent and consequent, and the transition from one to the other were of the nature of an instinct,—that is, the process is altogether unconscious and implicit. It is necessary, then, to take some notice of this natural or material Inference, as an existing phenomenon of mind; and that the more, because I shall thereby be illustrating and supporting what I have been saying of the characteristics of inferential processes as carried on in concrete matter, and especially of their being the action of the mind itself, that is, by its ratiocinative or illative faculty, not a mere operation as in the rules of arithmetic.

I say, then, that our most natural mode of reasoning is, not from propositions to propositions, but from things to things, from concrete to concrete, from wholes to wholes. Whether the consequents, at which we arrive from the antecedents with which we start, lead us to assent or only towards assent, those antecedents commonly are not recognized by us as subjects for analysis; nay, often are only indirectly recognized as antecedents at all. Not only is the inference with its process ignored, but the antecedent also. To the mind itself the reasoning is a simple divination or prediction; as it literally is in the instance of enthusiasts, who mistake their own thoughts for inspirations.

This is the mode in which we ordinarily reason, dealing with things directly, and as they stand, one by one, in the concrete, with an intrinsic and personal power, not a conscious adoption of an artificial instrument or expedient; and it is especially exemplified both in uneducated men, and in men of genius,—in those who know nothing of intellectual aids and rules, and in those who care nothing for them,—in those who are either without or above mental discipline. As true poetry is a spontaneous outpouring of thought, and therefore belongs to rude as well as to gifted minds, whereas no one becomes a poet merely by the canons of criticism, so this unscientific reasoning, being sometimes a natural, uncultivated faculty, sometimes approaching to a gift, sometimes an acquired habit and second nature, has a higher source than logical rule,—“nascitur, non fit.” When it is characterized by precision, subtlety, promptitude, and truth, it is of course a gift and a rarity: in ordinary minds it is biassed and degraded by prejudice, passion, and self-interest; but still, after all, this divination comes by nature, and belongs to all of us in a measure, to women more than to men, hitting or missing, as the case may be, but with a success on the whole sufficient to show that there is a method in it, though it be implicit.

A peasant who is weather-wise may be simply unable to assign intelligible reasons why he thinks it will be fine to-morrow; and if he attempts to do so, he may give reasons wide of the mark; but that will not weaken his own confidence in his prediction. His mind does not proceed step by step, but he feels all at once the force of various combined phenomena, though he is not conscious of them. Again, there are physicians who excel in the _diagnosis_ of complaints; though it does not follow from this, that they could defend their decision in a particular case against a brother physician who disputed it. They are guided by natural acuteness and varied experience; they have their own idiosyncratic modes of observing, generalizing, and concluding; when questioned, they can but rest on their own authority, or appeal to the future event. In a popular novel,(25) a lawyer is introduced, who “would know, almost by instinct, whether an accused person was or was not guilty; and he had already perceived by instinct” that the heroine was guilty. “I’ve no doubt she’s a clever woman,” he said, and at once named an attorney practising at the Old Bailey. So, again, experts and detectives, when employed to investigate mysteries, in cases whether of the civil or criminal law, discern and follow out indications which promise solution with a sagacity incomprehensible to ordinary men. A parallel gift is the intuitive perception of character possessed by certain men, while others are as destitute of it, as others again are of an ear for music. What common measure is there between the judgments of those who have this intuition, and those who have not? What but the event can settle any difference of opinion which occurs in their estimation of a third person? These are instances of a natural capacity, or of nature improved by practice and habit, enabling the mind to pass promptly from one set of facts to another, not only, I say, without conscious media, but without conscious antecedents.

Sometimes, I say, this illative faculty is nothing short of genius. Such seems to have been Newton’s perception of truths mathematical and physical, though proof was absent. At least that is the impression left on my own mind by various stories which are told of him, one of which was stated in the public papers a few years ago. “Professor Sylvester,” it was said, “has just discovered the proof of Sir Isaac Newton’s rule for ascertaining the imaginary roots of equations.... This rule has been a Gordian-knot among algebraists for the last century and a half. The proof being wanting, authors became ashamed at length of advancing a proposition, the evidence for which rested on no other foundation than belief in Newton’s sagacity.(26)”

Such is the gift of the calculating boys who now and then make their appearance, who seem to have certain short-cuts to conclusions, which they cannot explain to themselves. Some are said to have been able to determine off-hand what numbers are prime,—numbers, I think, up to seven places.

In a very different subject-matter, Napoleon supplies us with an instance of a parallel genius in reasoning, by which he was enabled to look at things in his own province, and to interpret them truly, apparently without any ratiocinative media. “By long experience,” says Alison, “joined to great natural quickness and precision of eye, he had acquired the power of judging, with extraordinary accuracy, both of the amount of the enemy’s force opposed to him in the field, and of the probable result of the movements, even the most complicated, going forward in the opposite armies.... He looked around him for a little while with his telescope, and immediately formed a clear conception of the position, forces, and intention of the whole hostile array. In this way he could, with surprising accuracy, calculate in a few minutes, according to what he could see of their formation and the extent of the ground which they occupied, the numerical force of armies of 60,000 or 80,000 men; and if their troops were at all scattered, he knew at once how long it would require for them to concentrate, and how many hours must elapse before they could make their attack.(27)”

It is difficult to avoid calling such clear presentiments by the name of instinct; and I think they may so be called, if by instinct be understood, not a natural sense, one and the same in all, and incapable of cultivation, but a perception of facts without assignable media of perceiving. There are those who can tell at once what is conducive or injurious to their welfare, who are their friends, who their enemies, what is to happen to them, and how they are to meet it. Presence of mind, fathoming of motives, talent for repartee, are instances of this gift. As to that divination of personal danger which is found in the young and innocent, we find a description of it in one of Scott’s romances, in which the heroine, “without being able to discover what was wrong either in the scenes of unusual luxury with which she was surrounded, or in the manner of her hostess,” is said nevertheless to have felt “an instinctive apprehension that all was not right,—a feeling in the human mind,” the author proceeds to say, “allied perhaps to that sense of danger, which animals exhibit, when placed in the vicinity of the natural enemies of their race, and which makes birds cower when the hawk is in the air, and beasts tremble when the tiger is abroad in the desert.(28)”

A religious biography, lately published, affords us an instance of this spontaneous perception of truth in the province of revealed doctrine. “Her firm faith,” says the Author of the Preface, “was so vivid in its character, that it was almost like an intuition of the entire prospect of revealed truth. Let an error against faith be concealed under expressions however abstruse, and her sure instinct found it out. I have tried this experiment repeatedly. She might not be able to separate the heresy by analysis, but she saw, and felt, and suffered from its presence.(29)”

And so of the great fundamental truths of religion, natural and revealed, and as regards the mass of religious men: these truths, doubtless, may be proved and defended by an array of invincible logical arguments, but such is not commonly the method in which those same logical arguments make their way into our minds. The grounds, on which we hold the divine origin of the Church, and the previous truths which are taught us by nature—the being of a God, and the immortality of the soul—are felt by most men to be recondite and impalpable, in proportion to their depth and reality. As we cannot see ourselves, so we cannot well see intellectual motives which are so intimately ours, and which spring up from the very constitution of our minds; and while we refuse to admit the notion that religion has not irrefragable arguments in its behalf, still the attempts to argue, on the part of an individual _hic et nunc_, will sometimes only confuse his apprehension of sacred objects, and subtracts from his devotion quite as much as it adds to his knowledge.

This is found in the case of other perceptions besides that of faith. It is the case of nature against art: of course, if possible, nature and art should be combined, but sometimes they are incompatible. Thus, in the case of calculating boys, it is said, I know not with what truth, that to teach them the ordinary rules of arithmetic is to endanger or to destroy the extraordinary endowment. And men who have the gift of playing on an instrument by ear, are sometimes afraid to learn by rule, lest they should lose it.

There is an analogy, in this respect, between Ratiocination and Memory, though the latter may be exercised without antecedents or media, whereas the former requires them in its very idea. At the same time association has so much to do with memory, that we may not unfairly consider that memory, as well as reasoning, depends on certain previous conditions. Writing, as I have already observed, is a _memoria technica_, or logic of memory. Now it will be found, I think, that indispensable as is the use of letters, still, in fact, we weaken our memory in proportion as we habituate ourselves to commit all that we wish to remember to memorandums. Of course in proportion as our memory is weak or over-burdened, and thereby treacherous, we cannot help ourselves; but in the case of men of strong memory in any particular subject-matter, as in that of dates, all artificial expedients, from the “Thirty days has September,” &c., to the more formidable formulas which are offered for their use, are as difficult and repulsive as the natural exercise of memory is healthy and easy to them; just as the clear-headed and practical reasoner, who sees conclusions at a glance, is uncomfortable under the drill of a logician, being oppressed and hampered, as David in Saul’s armour, by what is intended to be a benefit.

I need not say more on this part of the subject. What is called reasoning is often only a peculiar and personal mode of abstraction, and so far, like memory, may be said to exist without antecedents. It is a power of looking at things in some particular aspect, and of determining their internal and external relations thereby. And according to the subtlety and versatility of their gift, are men able to read what comes before them justly, variously, and fruitfully. Hence, too, it is, that in our intercourse with others, in business and family matters, in social and political transactions, a word or an act on the part of another is sometimes a sudden revelation; light breaks in upon us, and our whole judgment of a course of events, or of an undertaking, is changed. We determine correctly or otherwise, as it may be; but in either case, by a sense proper to ourselves, for another may see the objects which we are thus using, and give them quite a different interpretation, inasmuch as he abstracts another set of general notions from those same phenomena which present themselves to us.

What I have been saying of Ratiocination, may be said of Taste, and is confirmed by the obvious analogy between the two. Taste, skill, invention in the fine arts—and so, again, discretion or judgment in conduct—are exerted spontaneously, when once acquired, and could not give a clear account of themselves, or of their mode of proceeding. They do not go by rule, though to a certain point their exercise may be analyzed, and may take the shape of an art or method. But these parallels will come before us presently.

And now I come to a further peculiarity of this natural and spontaneous ratiocination. This faculty, as it is actually found in us, proceeding from concrete to concrete, belongs to a definite subject-matter, according to the individual. In spite of Aristotle, I will not allow that genuine reasoning is an instrumental art; and in spite of Dr. Johnson, I will assert that genius, as far as it is manifested in ratiocination, is not equal to all undertakings, but has its own peculiar subject-matter, and is circumscribed in its range. No one would for a moment expect that because Newton and Napoleon both had a genius for ratiocination, that, in consequence, Napoleon could have generalized the principle of gravitation, or Newton have seen how to concentrate a hundred thousand men at Austerlitz. The ratiocinative faculty, then, as found in individuals, is not a general instrument of knowledge, but has its province, or is what may be called departmental. It is not so much one faculty, as a collection of similar or analogous faculties under one name, there being really as many faculties as there are distinct subject-matters, though in the same person some of them may, if it so happen, be united,—nay, though some men have a sort of literary power in arguing in all subject-matters, _de omni scibili_, a power extensive, but not deep or real.

This surely is the conclusion, to which we are brought by our ordinary experience of men. It is almost proverbial that a hard-headed mathematician may have no head at all for what is called historical evidence. Successful experimentalists need not have talent for legal research or pleading. A shrewd man of business may be a bad arguer in philosophical questions. Able statesmen and politicians have been before now eccentric or superstitious in their religious views. It is notorious how ridiculous a clever man may make himself, who ventures to argue with professed theologians, critics, or geologists, though without positive defects in knowledge of his subject. Priestley, great in electricity and chemistry, was but a poor ecclesiastical historian. The Author of the Minute Philosopher is also the Author of the Analyst. Newton wrote not only his “Principia,” but his comments on the Apocalypse; Cromwell, whose actions savoured of the boldest logic, was a confused speaker. In these, and various similar instances, the defect lay, not so much in an ignorance of facts, as in an inability to handle those facts suitably; in feeble or perverse modes of abstraction, observation, comparison, analysis, inference, which nothing could have obviated, but that which was wanting,—a specific talent, and a ready exercise of it.

I have already referred to the faculty of memory in illustration; it will serve me also here. We can form an abstract idea of memory, and call it one faculty, which has for its subject-matter all past facts of our personal experience; but this is really only an illusion; for there is no such gift of universal memory. Of course we all remember, in a way, as we reason, in all subject-matters; but I am speaking of remembering rightly, as I spoke of reasoning rightly. In real fact memory, as a talent, is not one indivisible faculty, but a power of retaining and recalling the past in this or that department of our experience, not in any whatever. Two memories, which are both specially retentive, may also be incommensurate. Some men can recite the canto of a poem, or good part of a speech, after once reading it, but have no head for dates. Others have great capacity for the vocabulary of languages, but recollect nothing of the small occurrences of the day or year. Others never forget any statement which they have read, and can give volume and page, but have no memory for faces. I have known those who could, without effort, run through the succession of days on which Easter fell for years back; or could say where they were, or what they were doing, on a given day, in a given year; or could recollect accurately the Christian names of friends and strangers; or could enumerate in exact order the names on all the shops from Hyde Park Corner to the Bank; or had so mastered the University Calendar as to be able to bear an examination in the academical history of any M. A. taken at random. And I believe in most of these cases the talent, in its exceptional character, did not extend beyond several classes of subjects. There are a hundred memories, as there are a hundred virtues. Virtue is one indeed in the abstract; but, in fact, gentle and kind natures are not therefore heroic, and prudent and self-controlled minds need not be open-handed. At the utmost such virtue is one only _in posse_; as developed in the concrete, it takes the shape of species which in no sense imply each other.

So is it with Ratiocination; and as we should betake ourselves to Newton for physical, not for theological conclusions, and to Wellington for his military experience, not for statesmanship, so the maxim holds good generally, “Cuique in arte suâ credendum est:” or, to use the grand words of Aristotle, “We are bound to give heed to the undemonstrated sayings and opinions of the experienced and aged, not less than to demonstrations; because, from their having the eye of experience, they behold the principles of things.(30)” Instead of trusting logical science, we must trust persons, namely, those who by long acquaintance with their subject have a right to judge. And if we wish ourselves to share in their convictions and the grounds of them, we must follow their history, and learn as they have learned. We must take up their particular subject as they took it up, beginning at the beginning, give ourselves to it, depend on practice and experience more than on reasoning, and thus gain that mental insight into truth, whatever its subject-matter may be, which our masters have gained before us. By following this course, we may make ourselves of their number, and then we rightly lean upon ourselves; we follow our own moral or intellectual judgment, but not our skill in argumentation.

This doctrine, stated in substance as above by the great philosopher of antiquity, is more fully expounded in a passage which he elsewhere quotes from Hesiod. “Best of all is he,” says that poet, “who is wise by his own wit; next best he who is wise by the wit of others; but whoso is neither able to see, nor willing to hear, he is a good-for-nothing fellow.” Judgment then in all concrete matter is the architectonic faculty; and what may be called the Illative Sense, or right judgment in ratiocination, is one branch of it.