PART II. ELEMENTS OF PROOF CHAPTER I EVIDENCE 1 Importance of the Study of Evidence. From all that has been said in the preceding chapters on beginning principles, it is hoped that the student will be able to undertake intelligently the practice of debate. If, however, the student is to acquire skill in the use of these principles, he must become familiar with all the different elements involved in proof; for proof is the most fundamental process in debate. These elements are evidence and argument, which represent the means of proof; fallacy, which represents a serious defect in proof; and refutation, which represents a peculiar form of proof. Among these different elements, evidence is indispensable; and, hence, the study of evidence should be one of the most important subjects for consideration in the art of debate. Definition of Evidence. Evidence consists of any matter of fact that serves as a basis of proof. Distinguishing Qualities of Evidence. To determine what constitutes evidence and what does not, a debater must be able to distinguish clearly the difference between matters of fact and matters of theory, and also between matters of fact that serve, or do not serve, as a basis of proof. A matter of fact, as distinguished from a matter of theory, is concerned with the existence of things, the occurrence of 1 For lesson assignments on Evidence, see Appendix A. acts, the classification of objects, and the connection between events; whereas, a matter of theory is concerned with general laws or principles that may be employed in settling questions of fact or questions of policy. Not all matters of fact constitute evidence, however, but only those matters of fact that serve as a basis of proof. To serve in this capacity, a matter of fact must satisfy two requirements. First, it must be employed as a premise in argument; and, second, it must constitute a premise that demands no proof beyond the authority of common knowledge or the authority of a competent witness. Relation between Evidence and Argument. If the nature of evidence is to be clearly understood, something must be known also concerning the nature of argument. As has been said, proof consists entirely of evidence and argument. Argument is a process by which the mind is led from one or more assumed or known truths to acknowledge an alleged truth. The alleged truth that the mind is led to acknowledge through argument is called the conclusion. The mental process, involved in argument, in which the mind passes from the knowledge of one or more truths to the knowledge of another truth, is called inference. The assumed or known truths from which an inference is made are called the premises. These premises express either matters of theory or matters of fact. Whenever an argument is stated in full, one of its premises will contain a statement of the theory involved in the proof, and its other premise or premises will contain a statement of facts. If these facts stated in the premises can be accepted as true with no further proof than the authority of common knowledge or the authority of a competent witness, then they constitute evidence. Example of Evidence in Its Relation to Argument. - An example of evidence in its relation to argument is found in the following chain of reasoning taken from the proof submitted in Edmund Burke's speech on Conciliation with the Colonies: I. By admitting the colonies into an interest in the British Constitution, peace in America will be restored; for A. If peace was restored by this method in Wales, it would also be restored by the same means in America; and B. Peace was restored by this method in Wales; for 1. After the adoption of this policy toward Wales, the Welsh people became transformed from savages into a civilized nation; (Evidence) 2. Frontier raids upon England from Wales ceased; (Evidence) and 3. Invasion of Wales from England also ceased. (Evidence) In this chain of reasoning several arguments are introduced. The first involves the inference between the proposition marked I and the propositions marked A and B; and the second, third, and fourth involve respectively the inferences between the propositions marked B and 1; B and 2; B and 3. The propositions marked A and B are premises of the first argument; and the proposition marked B is the conclusion of the latter three arguments. The propositions marked 1, 2, and 3 are premises for the latter three arguments; and because they require no further proof than the authority of common knowledge to be themselves accepted as true, they constitute evidence. The propositions marked A and B, however, although they serve as premises, do not constitute evidence; because the proposition marked A constitutes theory rather than fact; and the proposition marked B constitutes a fact that seems to require further proof than the authority of common knowledge or the authority of a competent witness in order that it may be accepted as true. In the Objects to Be Sought in the Study of Evidence. chain of reasoning given above it will be noticed that all of the last subheadings constitute evidence. Every chain of reasoning must be based eventually on evidence; and, hence, it is extremely important that a debater be able to recognize, not only what constitutes evidence, but also what constitutes valid evidence. The objects to be sought, therefore, in the study of evidence will be: First, to understand all the various classes of evidence and the use that may be made of each; and second, to understand the tests that may be applied to determine the strength or weakness of one's own evidence and the evidence of one's opponent. I. CLASSES OF EVIDENCE Classification of Evidence. - Evidence may be classified in very many different ways, but perhaps the most serviceable basis for classification takes into consideration the form of the evidence, the relation that the evidence bears to its conclusion, and the source from which the evidence is obtained. All evidence may be classified by contrast in six different ways: Second, according to the relation it bears to its conclusion, as: Direct or Circumstantial Evidence; and Third, according to the nature of its source, as: Original or Hearsay Evidence; Written or Unwritten Evidence; and Real and Verbal Evidence. The first classification of evidence according to its form distinguishes all evidence as either real evidence or verbal evidence. Real evidence, in contrast with verbal evidence, consists of any object that may be used as an exhibit to demonstrate the truth of a debater's contentions; whereas, verbal evidence consists, not in objects themselves, but in statements concerning objects. Real evidence, for example, might consist of a bloodstained garment actually exhibited in a murder trial; a crippled arm exhibited in an accident case; or property that is viewed in a dispute over real estate. Verbal evidence, however, would consist of a statement about the blood-stained garment, about the crippled arm, or about the property in dispute. Use of Real and Verbal Evidence. Most evidence employed in debate is, of course, verbal evidence rather than real evidence. In spite of this fact, however, a debater should not overlook entirely the possibilities of real evidence. No opportunity should be missed by the debater to examine thoroughly whatever real evidence is available; and, whenever this evidence is favorable, he should seek to introduce it, if possible, in debate; because generally real |