THE PRINCIPLES OF JUDICIAL PROOF

AS CONTAINED IN LOGIC, PSYCHOLOGY, AND GENERAL EXPERIENCE AND ILLUSTRATED IN JUDICIAL TRIALS

INTRODUCTION

THIS book aspires to offer, though in tentative form only, a novum organum for the study of Judicial Evidence.

The study of the principles of Evidence, for a lawyer, falls into two distinct parts. One is Proof in the general sense, the part concerned with the ratiocinative process of contentious persuasion, - mind to mind, counsel to juror, each partisan seeking to move the mind of the tribunal. The other part is Admissibility, - the procedural rules devised by the law, and based on litigious experience and tradition, to guard the tribunal (particularly the jury) against erroneous persuasion. Hitherto, the latter has loomed largest in our formal studies, - has, in fact, monopolized them; while the former, virtually ignored, has been left to the chances of later acquisition, casual and empiric, in the course of practice. Here we have been wrong; and in two ways:

For one thing, there is, and there must be, a probative sciencethe principles of proof-independent of the artificial rules of procedure; hence, it can be and should be studied. This science, to be sure, may as yet be imperfectly formulated or even incapable of formulation. But all the more need is there to begin in earnest to investigate and develop it. Furthermore, this process of Proof is the more important of the two,—indeed, is the ultimate purpose in every judicial investigation. The procedural rules for Admissibility are merely a preliminary aid to the main activity, viz. the persuasion of the tribunal's mind to a correct conclusion by safe materials. This main process is that for which the jury are there, and on which the counsel's duty is focused. Vital as it is, its principles surely demand study.

And, for another thing, the judicial rules of Admissibility are destined to lessen in relative importance during the next generation or later. Proof will assume the important place; and we must therefore prepare ourselves for this shifting of emphasis. We must seek to acquire a scientific understanding of the principles of what may be called "natural" proof, - the hitherto neglected process. If we do not do this, history will repeat itself, and we shall find ourselves in the

present plight of Continental Europe. There, in the early 1800s the ancient worn-out numerical system of "legal proof" was abolished by fiat, and the so-called "free proof namely, no system at all was substituted. For centuries, lawyers and judges had evidenced and proved by the artificial numerical system; they had no training in any other, no understanding of the living process of belief; in consequence, when "legal proof" was abolished, they were unready, and judicial trials have been carried on for a century past by uncomprehended, unguided, and therefore unsafe mental processes. Only in recent times, under the influence of modern science, are they beginning to develop a science of proof.

Such will be our own fate, when the time comes, if we do not lay foundations to prepare for the new stage of procedure.

The present work seems to be the first attempt in English, since Bentham, to call attention to the principles of judicial Proof (distinguished from Admissibility) as a whole and as a system. It is therefore tentative. The chief service it aims to fulfill is to emphasize the subject as a science, and to stimulate its professional study.

The materials exist in abundance. But they need systematic collection and analysis. The illustrative materials here offered are culled from a wide range; though the search for them has merely touched the surface. A longer search would have found apter materials in many places, especially from the annals of civil trials. Most of the selections are from criminal cases; first, because they usually show the specific inference in more striking shape and shorter compass, and next, because they are the more profuse in the records. But it should not be forgotten that while blood and poison and pistol waddings are usually conceived as types of Circumstantial Evidence, yet the short and simple annals of civil cases are equally permeated with it, in less sensational form. Now a few words about the use of the book.

1. It is intended mainly for law-school work. But it may profitably be used (we hope) for the self-training of the maturer practitioner.

2. Though most of the topics are introduced or followed (as befits a novel subject) by a brief expository passage, to focus the reader on the possibilities of the topic, yet the main part of the material may and must be used inductively. Some of it merely illustrates; but most of it calls for self-application of the process of analysis and inference.

1 Mr. Burrill's masterly work, two generations ago, covered only a part of the field, Circumstantial Evidence. Mr. Moore's recent treatise (a valuable arsenal of extensive research), on Facts, or The Weight and Value of Evidence, deals in substance with Testimonial Evidence only. Mr. Justice Stephen's introduction to the Indian Evidence Act, entitled The Principles of Judicial Evidence (1872), contains a brief though thoroughly scientific survey of the subject; and perhaps his exposition should be classed as an attempt at a system. He seems to have believed that the logical Methods of Agreement and of Difference supplied the sufficient key to all such questions ("the principle is precisely the same in all cases, however simple or however complicated"). Inadequate though this may be deemed, certainly his point of view is so plausibly stated that it must be reckoned with in any future proposals of a system. The present exposition not being controversial, no attempt is made to note the objections to Mr. Justice Stephen's method.

On the Continent, the great pioneer work of Hans Gross, entitled (not happily) "Criminal Psychology" (translated in the Modern Criminal Science Series) is still the only systematic treatise on the psychology of testimony. However, not being written from the point of view of our law, its system is not directly available.

There is a probative moral to every one of the cases; to point out in footnotes the moral as conceived by the compiler would have spoiled the object of the book. The profitable use of the book will be to employ each illustrative case rigidly as a mental exercise somehow bearing on the subject where it is classified. In this field no one can afford to let another do his thinking for him.

3. There is no attempt to cover all kinds of evidential data. Many minor but troublesome varieties (for example, handwriting, hearsay, corroboration of witnesses) are ignored, partly because space did not permit, partly because their treatment might doubtfully complicate the system here offered. Some day a system will arise into which all of

these can easily be fitted.

4. In the use of these materials, the following warning suggestions are offered:

(a) Do not attempt to invoke mentally any of those exclusionary rules of Admissibility commonly thought of as the rules of evidence. Keep them out of the ratiocinative process. Think of the problem as a juror would think of it if the evidence were safely in the case and the counsel were arguing to him about it. What we are aiming to analyze is the actual mind-to-mind process of persuasion and belief.

(b) Do not assume that any of the quoted extracts purporting to describe (especially in Part II) the facts of experience in various sorts of testimony are here put forward as sound. Give them such credence as their chroniclers may seem to deserve; but test them by your own experience, and apply such discount as may seem needed. Those materials are here offered merely as materials for reflection, and not as dogmas of truth.

(c) Use Parts I and II as simply preliminary, i.e. as a drill in method of analysis, and a supply of data of experience to supplement one's own. Then make Part III (Problems in Masses of Evidence) the main objective. Parts I and II are like the elemental moves or strokes in chess or in golf; they must of course first be studied; but the real thing is the game. Or they are like the various scales, arpeggios, and chords in music; they are the component parts, in varying form, for every one of a million pieces of music; but the musical piece is what we always expect ultimately to play or to hear. The single bits or kinds of evidence, as presented in Parts I and II, must first for exercitation be taken apart and analyzed, each by itself; but in judicial trials single kinds of evidence are not thus presented in segregated form. What is really found is a mixed mass of evidence, culminating in a single large issue (or series of issues): "Did he, or did he not?" Was it, or was it not?" In Part III, and there only, we have the problem of Proof as it is actually forced upon us every day in

our courts.

5. Part III thus represents the ultimate and most difficult aspect of the principles of Proof; namely, the method of solving a complex mass of evidence in contentious litigation. Such a method is here suggested (in No. 376). Nobody yet seems to have ventured to offer a method, neither the logicians (strange to say), nor the psychologists, nor the jurists, nor the advocates. The logicians have furnished us in plenty

with canons of reasoning for specific single inferences; but for a total mass of contentious evidence, they have offered no system.1 What is here put forward is a mere provisional attempt at method. One must have a working scheme. If this will not work, try to devise some other, or try what success there is in getting along without any.

The problems in Part III will offer a varied range for testing the practicability of whatever scheme one may devise. But some method there ought to be. It seems incredible that advocates can have got along without any, through the long period of judicial annals. What is wanted is simple enough in purpose, namely, some method which will enable us to lift into consciousness and to state in words the reasons why a total mass of evidence does or should persuade us to a given conclusion, and why our conclusion would or should have been different or identical if some part of that total mass of evidence had been different. The mind is moved; then can we not explain why it is moved? If we can set down and work out a mathematical equation, why can we not set down and work out a mental probative equation?

In offering this collection of illustrations and problems as a help towards the attainment of this higher purpose, the Compiler realizes the inadequacy of his own contributions (mainly No. 376, herein) towards developing a sound and workable method. Yet, as Locke put it, "He that will not stir till he infallibly knows that the business he goes about will succeed, will have but little else to do but to sit still and perish. And there is at least the consolation of believing that the illustrations will furnish entertaining reading in a field little patronized hitherto by lawyers. And along with this entertainment ought to come some consciousness of the importance of the general problem, and a resolve to bring the Courts and the Bar to recognize the coming stage of the law of Evidence, an epoch in which the present rules of Admissibility, already become too largely formalistic and unreal, will be partly supplanted by a new method.

1 The feasibility of such a system has indeed been questioned in their ranks. Thus : "The theory of probabilities is the very guide of life; hardly can we take a step or make a decision of any kind without correctly or incorrectly making an estimation of probabilities. . . . Attempts to apply the theory of probability to the results of judicial proceedings have proved of little value, simply because the conditions are far too intricate.

No mathematical formulas can be framed to express the real conditions. ... But such failures in no way diminish the truth and beauty of the theory itself; in reality there is no branch of science in which our symbols can cope with the complexity of Nature. . . The difficulty, in short, is merely relative to our knowledge and skill, and is not absolute or inherent in the subject." (W. Stanley Jevons, The Principles of Science: a Treatise on Logic and Scientific Method, p. 34, 2d ed., 1877, reprint of 1907.) If anybody could have performed this service for Judicial Evidence, Jevons was the man to do it. His Logical Abacus and Logical Machine shows that he had the keenest appreciation of the possibilities.

Through the kind assistance of his colleague, Professor Horace C. Longwell, the present author has consulted the modern works on Logic, but must still avow that, for the purposes of judicial controversy, they do not afford the desired help.