The Making of Arguments

by J. H. Gardiner

CHAPTER III

EVIDENCE AND REASONING

27. Evidence and Reasoning. We have seen in the last chapter that the chief value of making a brief is that in the first place it lays out your reasoning so that you can scrutinize it in detail; and that in the second place it displays the foundations of your reasoning on facts which cannot be contested. In this chapter we shall consider what grounds give validity to evidence and to reasoning.

Where the facts which you bring forward come from persons with first-hand knowledge of them, they are direct evidence; where you must establish them by reasoning from other facts they are indirect evidence, and in the latter case reasoning is an essential part of establishing the facts. In this chapter, therefore, I shall speak first of direct evidence, then of indirect, and then pass on to consider a few of the simpler principles which govern reasoning.

In ordinary usage the word "evidence" is pretty vague, and means anything that will help to establish one side or another of any question, whether of fact or of policy. The word, however, comes ultimately from the law, where it is used for the testimony, either oral or written or material, which is brought in to establish the truth of assertions about fact: evidence is set before the jury, which under the common law decides questions of fact. In almost any argument of policy, however, we use facts as reasons for or against the policy which is in question, and therefore inmost cases we must use evidence to establish these facts; in many cases, when the facts are established there is no further disagreement about the policy. For example, in arguments for and against state prohibition of the liquor trade, it is an essential fact to determine whether in status where prohibition has been tried it has failed or succeeded, and another essential fact whether under similar conditions a combination of high license and local option has or has not produced less drunkenness. Both are extremely complicated and difficult facts to decide; but if clear evidence can be brought forward to establish them, reasonable-minded people would generally hold as settled the question of the policy which should be adopted. Similarly, an argument for the popular election of senators would undoubtedly make large use of the alleged fact that, in elections by the legislatures, there has been much undue interference by special interests and rich corporations; and the assertion of this fact would have to be supported by evidence. If this fact were thus clearly established, it would be recognized as a strong reason for a change in our present policy. In the interest of clearness of thought it is worth while to remember this distinction; for, as we shall see, it is only by so doing that we can determine when the ordinary rules of logic do and when they do not apply to the processes of reasoning on which argument is based. I shall speak here, therefore, of the evidence for facts, and of the reasons for or against a policy.

It may be said in passing that the highly complicated rules of evidence at the common law have practically nothing to do with our present subject, for they spring from very special conditions, and have been molded by very special purposes. Their object is to establish, so far as is possible, principles which will apply to all cases of a like nature; and they therefore rule out many facts and much evidence which outside the court we all use without hesitation in making up our minds. The jury system has had a curious and interesting history: and judges have built up hedges around juries which seem to the layman merely technical, and unnecessary for the ends of justice.[¹⁴][!--Note--] Yet though the sweeping away of many of these rules from time to time shows that there has been and perhaps still is justice in this view, one must remember that the whole common law is based on the application of principles already established by earlier cases to new cases of like character; and that great care must therefore be used not to establish principles which may interfere with the even distribution of justice in the long run (see on this point S.R. Gardiner, p. 103). Even if in single cases the rule of evidence that forbids hearsay evidence works an injustice, yet in the long run it is obvious both that, if hearsay were allowed, litigants would take less trouble to get original evidence, and that much hearsay is thoroughly untrustworthy.

Another reason why the rules of evidence at the common law have little bearing on the arguments of everyday life is like that which makes it unwise to dwell much on the burden of proof: there is no one either competent or interested to enforce the exclusion. Assertion and rumor must be more than palpably vague before the ordinary man will of his own initiative take the trouble to scrutinize it; and even in refuting such material you must make its untrustworthiness very patent if you expect to make ordinary readers distrust it seriously.

28. Direct and Indirect Evidence. When we come now to consider how we establish facts, whether single or complex, we find that, both to aid our own judgment and to convince other people, we rely on evidence. We have seen that evidence falls roughly into two classes: either it comes from persons who testify out of their own observation and experience, or it comes indirectly through reasoning from facts and principles already established or granted. The two kinds of evidence run into each other, and the terms commonly used to describe them vary: "direct evidence" is not infrequently, as in Huxley's argument (see p. 240), called "testimonial," and "indirect evidence," as in the same argument and in the opinion of Chief Justice Shaw, quoted below, is called "circumstantial." On the whole, however, the opposition between the two classes, so far as it is of practical importance, may best be indicated by the terms "direct evidence" and "indirect evidence." The distinction between the two classes is made clear in the following extract from the opinion of Chief Justice Shaw of the Massachusetts Supreme Court. It will be noticed that it is the same doctrine as that laid down by Huxley (see p. 240).

The distinction, then, between direct and circumstantial evidence is this. Direct or positive evidence is when a witness can be called to testify to the precise; fact which is the subject of the issue in trial; that is, in a case of homicide, that the party accused did cause the death of the deceased. Whatever may be the kind or force of the evidence, this is the fact to be proved. But suppose no person was present on the occasion of the death,—and of course no one can be called to testify to it,—is it wholly unsusceptible of legal proof? Experience has shown that circumstantial evidence may be offered in such a case; that is, that a body of facts may be proved of so conclusive a character, as to warrant a firm belief of the fact, quite as strong and certain as that on which discreet men are accustomed to act in relation to their most important concerns....

Each of these modes of proof has its advantages and disadvantages; it is not easy to compare their relative value. The advantage of positive evidence is, that you have the direct testimony of a witness to the fact to be proved, who, if he speaks the truth, saw it done; and the only question is, whether he is entitled to belief. The disadvantage is, that the witness may be false and corrupt, and the case may not afford the means of detecting his falsehood.