The only means of proof 2. The means of proof: Evidence. is what, in a term borrowed from the profession of law, is called evidence. Evidence is " any matter of fact, the effect, tendency, or design of which is to produce in the mind a persuasion affirmative or disaffirmative of the existence of some other matter of fact." 1 Thus we may see that much so-called argument, mere assertion of belief or opinion, is not proof at all. Children and the unlettered may be excused for spending their time in asking that their words be accepted as final; but adults, though they have attained a position in the world which would seem to entitle them to an opinion, will, unless completely ignored, be asked to offer something additional which partakes of the nature of fact. 3. Two kinds of evidence. For convenience, evidence is usually divided into two classes, - direct and circumstantial. The first of these, direct evidence, tends to establish a fact immediately without any intervening inferences. Thus, if five students say they saw Kay, a classmate, cheating in an examination, the evidence is direct. If they really saw him making use of unfair means, the question is settled. But direct evidence is not always reliable. In the first place, the witnesses may not be truthful. Possibly these five students did not see their classmate cheat at all. It may be that he had offended them on some previous occasion and that they agreed to make a false report concerning his conduct in order to "get even." Moreover, direct evidence has its weaknesses, even if the motives of the witnesses cannot be questioned. Possibly, for example, the five students were unduly agitated over the character of the examination and thought they saw him copying from a slip of paper when, as a matter of fact, he was not doing so; or possibly they were unconsciously influenced by prejudice arising from his superior scholarship. Thus, in a number of ways, direct evidence may fail to prove. Nevertheless, when the witness appears to be truthful and intelligent, his testimony ordinarily carries conviction. 1 Best, On Evidence, p. 5. Circumstantial evidence "tends to prove a fact in issue by proving other events or circumstances which, according to the common experience of mankind, are usually or always attended by the fact in issue." It is, therefore, not a kind of evidence that proves immediately, but by inference from accepted facts. Thus, nobody saw Kay cheat in an examination, but he had been openly charged by Stanton, a fair-minded student, with stealing a ring; he had not studied seriously just before the examination, and he had "loafed" throughout the earlier part of the half-year; he was, moreover, a weak student normally, and rarely made creditable grades; he had on the morning of the examination boasted that he would make an A; his examination paper revealed a surprising amount of concrete detail; and when the next day he was called before the Committee on Scholarship, he had "forgotten some of the details that he had used skillfully in answering the examination questions. No one of these facts standing alone would justify us in saying that Kay cheated, yet the inference which, in the light of our experience, we draw from all the facts taken together, is that probably he was guilty. Still, this may be a case which represents the weakness of circumstantial evidence; we may have drawn the wrong inferences from the facts. It is possible that Kay entered Stanton's room just after a gust of wind had rolled the ring into an open register; he may have made the boast about making an A simply because he was aware that everybody knew him to be a poor student; his high grade on the examination was possibly due to the fact that the questions, as sometimes happens, called for the few concrete details he had "absorbed " in the course; and his inability to remember when questioned by the Committee the next day may have been the result of worry caused by a wholly false accusation that seemed difficult to disprove. Our experience has convinced us that there is always the possibility of more than one inference from a given set of facts. Nevertheless, circumstantial evidence frequently serves as a test of direct evidence. Sometimes the testimony of imperfect 1 International Dictionary. human beings is entirely set at naught by the unprejudiced, unalterable circumstances attendant upon the matter at issue. Let us take an example from politics. In the autumn of 1911 it was said " on good authority" that the political unfriendliness shown by William Jennings Bryan toward Governor Harmon, of Ohio, was due to an unguarded remark made in 1908 by Governor Harmon's young daughter. This daughter, it was said, not being old enough to know when to keep dinner-table secrets, told a very intimate girl friend in Texas, who was also the friend of one of the daughters of Mr. Bryan, that "good old daddy doesn't care if Mr. Bryan is defeated, for then he'll be out of the way in 1912." Inasmuch as it was known that both Governor Harmon and Mr. Bryan had daughters, the supposed explanation found many willing believers. An investigation, however, revealed circumstances that made the story absolutely impossible. (1) Governor Harmon's daughters, all married, left home long before the campaign of 1908. (2) Not one of them ever had a girl or woman friend in Texas. (3) Not even his granddaughters could have taken part in the supposed transaction, for at that time the elder of the two was only six years old. It matters not how high the "authority" may be, it cannot maintain itself in the face of evidence of this kind. The ideal in proof is, of course, to combine direct and circumstantial evidence. Things may not be what they seem to our senses, and there may be serious doubt about the value that should be attached to inferences we have drawn from circumstantial facts; but if the direct evidence, the testimony of persons who observed the fact at issue, is supported by inferences from a chain of circumstances, or if, on the other hand, inferences are supported by a reasonable amount of direct evidence, there usually is little doubt about the merits of the question. If, for example, to return to our first illustration, several students should testify that they saw Kay cheat in an examination, and all the attendant circumstances pointed to his guilt, it would be very difficult to explain away both the direct evidence and the inferences. Sometimes an attempt at such an explanation is successful, yet usually when observation and inferences harmonize, very little "reasonable doubt " remains. 4. Sources of evidence. If the proving of such a simple case as the one that has served us in illustrating the difference between direct and circumstantial evidence has so many possibilities, we can see at once that a proposition which involves a large number of facts, the experience of many men, and the interest of many others, could not be proved easily or simply. The variety of evidence that the proving of such a proposition demands makes it important that a student know every possible means of finding evidence and of bringing it to bear. The chief sources are personal observation, the testimony of individuals, newspaper files, magazines, government documents, reports of special commissions and committees, and books of reference. He must be able, therefore, to make first-hand observations and see their significance; he must know how to direct conversation with people who are interested in the subject; he must get the drift of opinion by reading magazine articles and other general discussions; and he must follow possible lines of argument by reading special treatises and authoritative and official documents. All these sources he must know how to use. Furthermore, he must know how to make them fruitful by classifying and organizing the material which he gets from them. He must not let himself believe that good intentions or sterling honesty or clever wit will take the place of abundant facts. 5. Selection of evidence. But we cannot profitably employ all the evidence we draw from these sources. In the first place, it is not all of equal weight. Moreover, the prejudices of the audience who will read the argument, their intellectual grade, and the character of other arguments that they have read or heard or will probably read or hear, make it advisable to choose between points that in the mind of the writer may seem to be equally important. Thus we come again to one of the cardinal principles of all creative work, - selection. We cannot, to be sure, select evidence according to rigid rule, yet it is advisable to keep in mind some principles of choice that are well established. First of all, the evidence should give the important parts of our argument their due emphasis. Secondly, it should meet squarely any important arguments which we are certain our readers will have in mind, either through previous reading or through a mere desire to believe the other side. Thirdly, the whole body of evidence which we submit should give the impression of fairness; for, we must always remember, the purpose of argument is to make it easy for the indifferent, the doubtful, and the antagonistic to believe as we believe. Finally, the evidence should be chosen for the constructive harmony of its parts. That is to say, the individual points when brought into logical relation with one another should produce not only individual effects, but a convincing total effect. The completed argument should be more than equal to the sum of its parts. - 6. Tests of evidence. If all arguing were pure reasoning about unquestioned facts, the problem of convincing our friends would be comparatively simple. Such a happy state of affairs would make it possible for the most elementary mind to reach thoroughly satisfactory logical conclusions. Unfortunately, however, the lot of mankind has been cast in a place where such Utopian conditions do not exist. Instead of enjoying the simple pastime of performing clever logical tricks with such unprejudiced people as X, Y, and Z, we must deal with concrete men and women whose senses are imperfect, whose lives are full of inherited or acquired prejudices, and whose nearest approach to truth has been in a world where only half-truths exist. We must, then, in finding and selecting evidence, constantly guard against error by testing our own evidence and that which others have used in treating the same matters. a. Testing the source of evidence. At the outset we should test the source of evidence. We should know what the source of evidence is, and whether this source is generally accepted as trustworthy. If, for example, in the preparation of a paper we must base our argument on the oral or written testimony of a witness, we must know first of all whether he is reliable. |