Many of these presumptions are based on no real estimate of probabilities, but are established for the purpose of placing the burden of proof upon the party who is best able to bear it, or who may most justly be made to bear it. Persons accused of crime are probably guilty, but the presumption of their innocence is in most cases and with certain limitations clearly expedient.
III. Insufficient evidence.—In the third place the law contains rules declaring that certain evidence is insufficient, that its probative force falls short of that required for proof, and that it is therefore not permissible for the courts to act upon it. An example is the rule that in certain kinds of treason the testimony of one witness is insufficient—almost the sole recognition by English law of the general principle, familiar in legal history, that two witnesses are necessary for proof.
IV. Exclusive evidence.—In the fourth place there is an important class of rules declaring certain facts to be exclusive evidence, none other being admissible. The execution of a document which requires attestation can be proved in no other way than by the testimony of an attesting witness, unless owing to death or some other circumstance his testimony is unavailable. A written contract can be proved in no other way than by the production of the writing itself, whenever its production is possible. Certain kinds of contracts, such as one for the sale of land, cannot be proved except by writing, no verbal testimony being of virtue enough in the law to establish the existence of them.
It is only in respect of very special kinds of contracts that written evidence can wisely be demanded by the law. In the case of all ordinary mercantile agreements such a requirement does more harm than good; and the law would do well in accepting the principle that a man’s word is as good as his bond. The Statute of Frauds, by which most of these rules of exclusive evidence have been established, is an instrument for the encouragement of frauds rather than for the suppression of them. How much longer is it to remain in force as a potent instrument for the perversion of English law? Its repeal would sweep away at one stroke the immense accumulation of irrational technicality and complexity that has grown in the course of centuries from this evil root.
V. Facts which are not evidence.—Fifthly and lastly there are rules declaring that certain facts are not evidence, that is to say, are destitute of any probative force at all. Such facts are not to be produced to the court, and if produced no weight is to be attributed to them, for no accumulation of them can amount to proof. For example, hearsay is no evidence, the bond of connexion between it and the principal fact so reported at second hand being in the eye of the law too slight for any reliance to be justly placed upon it. Similarly the general bad character of an accused person is no evidence that he is guilty of any particular offence charged against him; although his good character is evidence of his innocence.
These rules of exclusion or irrelevancy assume two distinct forms, characteristic respectively of the earlier and later periods in the development of the law. At the present day they are almost wholly rules for the exclusion of evidence; in earlier times they were rules for the exclusion of witnesses. The law imposed testimonial incapacity upon certain classes of persons on the ground of their antecedent incredibility. No party to a suit, no person possessing any pecuniary interest in the event of it, no person convicted of any infamous offence, was a competent witness. His testimony was deemed destitute of evidential value on account of the suspicious nature of its source. The law has now learned that it is not in this fashion that the truth is to be sought for and found. It has now more confidence in individual judgment and less in general rules. It no longer condemns witnesses unheard, but receives the testimony of all, placing the old grounds of exclusion at their proper level as reasons for suspicion but not for antecedent rejection. Whether rules for the exclusion of evidence are not in general exposed to the same objections that have already prevailed against the roles for the exclusion of witnesses is a question which we shall presently consider.
§ 175. The Production of Evidence.
The second part of the law of evidence consists of rules regulating its production. It deals with the process of adducing evidence, and not with the effect of it when adduced. It comprises every rule relating to evidence, except those which amount to legal determinations of probative force. It is concerned for example with the manner in which witnesses are to be examined and cross-examined, not with the weight to be attributed to their testimony. In particular it includes several important rules of exclusion based on grounds independent of any estimate of the probative force of the evidence so excluded. Considerations of expense, delay, vexation, and the public interest require much evidence to be excluded which is of undoubted evidential value. A witness may be able to testify to much that is relevant and important in respect of the matters in issue, and nevertheless may not be compelled or even permitted to give such testimony. A public official, for example, cannot be compelled to give evidence as to affairs of state, nor is a legal adviser permitted or compellable to disclose communications made to him by or on behalf of his client.
The most curious and interesting of all these rules of exclusion is the maxim, Nemo tenetur se ipsum accusare. No man, not even the accused himself, can be compelled to answer any question the answer to which may tend to prove him guilty of a crime. No one can be used as the unwilling instrument of his own conviction. He may confess, if he so pleases, and his confession will be received against him; but if tainted by any form of physical or moral compulsion, it will be rejected. The favour with which this rule has been received is probably due to the recoil of English law from the barbarities of the old Continental system of torture and inquisitorial process. Even as contrasted with the modern Continental procedure, in which the examination of the accused seems to English eyes too prominent and too hostile, the rule of English law is not without merits. It confers upon a criminal trial an aspect of dignity, humanity, and impartiality, which the contrasted inquisitorial process is too apt to lack. Nevertheless it seems impossible to resist Bentham’s conclusion that the rule is destitute of any rational foundation, and that the compulsory examination of the accused is an essential feature of sound criminal procedure. Even its defenders admit that the English rule is extremely favourable to the guilty, and in a proceeding the aim of which is to convict the guilty, this would seem to be a sufficient condemnation. The innocent have nothing to fear from compulsory examination, and everything to gain; the guilty have nothing to gain, and everything to fear. A criminal trial is not to be adequately conceived as a fight between the accused and his accuser; and there is no place in it for maxims whose sole foundation is a supposed duty of generous dealing with adversaries. Subject always to the important qualification that a good prima facie case must first be established by the prosecutor, every man should be compellable to answer with his own lips the charges that are made against him.[[477]]
A matter deserving notice in connexion with this part of the law of evidence is the importance still attached to the ceremony of the oath. One of the great difficulties involved in the process of proof is that of distinguishing between true testimony and false. By what test is the lying witness to be detected, and by what means is corrupt testimony to be prevented? Three methods commended themselves to the wisdom of our ancestors. These were the judicial combat, the ordeal, and the oath. The first two of these have long since been abandoned as ineffective, but the third is still retained as a characteristic feature of judicial procedure, though we may assume with some confidence that its rejection will come in due time, and will in no way injure the cause of truth and justice.