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ESSAY ON THE RATIONALE OF CIRCUMSTANTIAL EVIDENCE.

BY WILLIAM WILLS, ESQ.

NEW

Or the various kinds of moral evidence, that of testimony is the most important and comprehensive in its relation to human concerns; and, considering how many of our daily determinations are grounded upon that kind of evidence, even where we least suppose that we are pursuing a logical process, and how important it is that our judgments should be correctly formed, the subject is one of deep curiosity and interest. To enter upon the subject of testimony at large, would be to treat of the conduct of the human understanding in relation to the greater portion of the affairs of life. A due regard to unity of plan requires that I abstain from even glanc-` ing at many kindred and interesting topics, and that I restrict my observations as much as possible to that specific portion of moral evidence which I propose to consider.

It would be erroneous and unjust, because the subject is best capable of illustration by forensic occurrences, to conclude that it more especially concerns the pursuits or the members of a particular profession. Such events are amongst the most deeply touching and dramatic incidents of social life; and throw a fearful light upon the darker parts of human nature, as earthquakes and volcanoes disclose the layers which compose the deeper parts of our planet, beneath a fertile and flowery surface." The subject is of universal concernment, and relates to an intellectual process applicable to every branch of human speculation.

It is desirable to clear the subject of ambiguity from the inaccurate use of language. The word proof is often applied to that which is merely the medium of proof. The judgment in relation to any alleged fact is always founded upon evidence, and when the result is that state of opinion which we distinguish by the term belief, we correctly say that the subject-matter of our inquiry is proved. Proof, then, is that quantity of evidence which produces belief, and they severally differ as cause and effect.

The epithets direct, or indirect, or circumstantial, as applied to moral evidence, have been sanctioned by such long and general use that it might seem presumptuous to question their accuracy, as it

*Mackintosh, Ethical Dissertation, p. 228.

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would be needless and perhaps impracticable to substitute others; but their distinctive propriety is certainly not evident, and the misuse of them has occasionally been the cause of lamentable errors.

On a superficial view it might be thought that the terms direct and circumstantial denote distinct kinds of evidence, whereas in reality they denote only the different probative nature of evidentiary facts themselves. The actual distinction is, that by direct evidence is intended proof of the fact which is the subject of inquiry-the factum probandum. Circumstantial evidence is equally direct in its nature, but it is direct evidence of a minor fact or collection of facts more or less usually connected with some other fact, and from which it is usually inferred. A fact of this latter kind is called factum probans.

The term presumptive is frequently used as synonymous with circumstantial evidence, but it is never so applied with accuracy. A presumption is a probable consequence drawn from proved facts, as to the truth of a fact alleged, but of which there is no direct proof. The word presumption, therefore, inherently imports a conclusion of the judgment, based upon circumstantial evidence; and it is more accurate to apply it only to conclusions from facts or moral phenomena. A wounded and bleeding body is discovered; it has been plundered; wide and deep footmarks are found proceeding in a direction from the body. These circumstances induce the conclusion that a crime has been committed, and that conclusion is properly termed a presumption. The Judgment of Solomon is a memorable instance of a presumption afforded by moral phenomena.

Direct and circumstantial evidence are essentially distinguished by the manner in which they produce belief. So rapid are our intellectual processes, that it is frequently impossible to trace the connection between an act of the judgment and the train of reasoning of which it is the consequence; and the one appears to succeed the other by a kind of necessity, as the thunder follows the flash. But the case is widely different when we have to determine upon circumstantial evidence, the judgment in respect of which is essentially deductive and inferential; the facts may be true and the deduction false, and it is only by long experience that we acquire confidence in the accuracy of our conclusions.

It is essential in all investigations founded upon moral evidence, and especially upon circumstantial evidence, that we correctly estimate the kind and degree of assurance of which the subject admits. The end of all intellectual research is the discovery of truth, or the conformity or disagreement of ideas. Abstract truth concerns ne

cessary relations, and its first principles are definitions which exclude all ambiguity of language and ideas, and lead infallibly from step to step to conclusions the most remote from common apprehension. But the subjects which admit of mathematical certainty are comparatively few. Innumerable truths, the knowledge of which is indispensable to happiness, and even to existence, must be believed upon evidence of an inferior kind. The subjects of moral evidence are facts and relations which may or may not exist, and as to which our reasonings and conclusions may be erroneous and false. In the case of abstract truth, absolute and infallible demonstration is the result, to which moral certainty the highest assurance we can have of moral truth, is obviously and necessarily inferior.

Numerous attempts have been made to give mathematical form and precision to moral reasoning, but to little purpose, except as they shew the ingenuity of their authors; and, without presumption, they may be declared to be destitute of any useful and practicable application. A learned author, whose high praise it is to have "done more than any other writer to rouse the spirit of judicial reform," but whose merits have been obscured by his eccentricities of thought as well as of style, has gravely demanded whether Justice requires less precision than Chemistry. The truth is that the precision required in the one case is of a nature of which the other does not admit. It would surely be absurd to require the proof of a moral or historic fact by the same kind of reasoning as that by which we establish that the three angles of every triangle are exactly equal to two right angles; or that, in certain of the conic sections, the latus rectum is a third proportional to the major and minor axes.

Unlike the assent which is given to mathematical truth, belief may be of various degrees, between the highest and lowest of which there are innumerable shades of conviction, which the latency of mental operations, and the imperfections of language, render it impossible to define or express. Nor is it material, in relation to subjects of moral inquiry, that exact expression cannot be given to the inferior degrees of belief. The doctrine of chances, and nice calculations of probability, cannot be applied to human actions, which are essentially unlike, and dependent upon peculiarities of person and of circumstances, which render it impossible to compare them with a numeral standard.

It is true, that, in the common affairs of life, we are frequently obliged from necessity and duty to act upon evidence which produces the lowest state of belief; and Locke very justly remarks,

that "he who will not stir till he infallibly knows the business he goes about will succeed, will have little else to do, but sit still and perish.”* But in such cases our judgments concern ourselves, and our own duties and interests; while in moral judgments and penal jurisprudence, a rule of action is applied to the conduct of others, where external and sometimes ambiguous indicia constitute the only basis of judgment. In the application of a rule of action, the moral certainty of the facts is its only just foundation and vindication, and upon any lower degree of assurance it would be arbitrary and indefensible.

But, though a process purely mathematical cannot be applied to moral evidence, a proceeding somewhat analogous is always followed in the examination of a group of facts which are adduced as reasons for inferring the existence of another fact. We mentally collect on one side of the equation all the circumstances which have an affirmative value, and on the other, all those which lead to the opposite inference, or which diminish or destroy the weight or relevancy of the facts which have been put into the opposite scale. As in algebraic addition, we incorporate the opposite quantities, positive and negative, and the balance of probabilities constitutes the ground of human judgment and belief.

The best writers on the subject of moral evidence, have been unanimous in treating circumstantial as inferior in cogency to direct evidence; a conclusion which seems to follow necessarily from the very nature of these different kinds of evidence. But assertions of a different import are to be found in some late authorities.

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It has been said that "circumstances are inflexible proofs; that witnesses may be corrupted or mistaken, but things can be neither.”+ Circumstances," says Paley "cannot lie." It is astonishing that sophisms like these should have passed undetected. These passages assume the circumstances to be in every case established beyond all possibility of mistake, and that the conclusions from them are necessary and infallible;-and imply that circumstantial evidence possesses some mysterious force peculiar to facts of a certain class. Now, a circumstance is neither more nor less than a minor fact; and it may be admitted of all facts that they cannot lie; for a fact cannot at the same time exist and not exist, so that the doctrine expresses a mere truism, that a fact is a fact. It may also be admitted that circumstances are "inflexible proofs;" but so

*

Essay on the Human Understanding, b. 4, c. 14, s. 1. + Burnett, On the Criminal Law of Scotland.