2. In another sense by witness is understood one who is called upon to be present at a transaction, as a wedding, or the making of a will. When a person signs his name to an instrument, as a deed, a bond, and the like, to signify that the same was executed in his presence, he is called an attesting witness.
3. The testimony of witnesses can never have the effect of a demonstration, because it is not impossible, indeed it frequently happens, that they are mistaken, or wish themselves to deceive. There can, therefore, result no other certainty from their testimony than what arises from analogy. When in the calm of the passions, we listen only to the voice of reason and the impulse of nature we feel in ourselves a great repugnance to betray the truth, to the pre-judice of another, and we have observes that honest, intelligent and disinterested persons never combine to deceive others by a falsehood. We conclude then, by analogy, with a sort of moral certainty, that a fact attested by several witnesses, worthy of credit, is true. This proof derives its whole force from a double presumption. We presume, in the first place, on the good sense of the witnesses that they have not been mistaken; and, secondly, we presume on their probity that they wish not to deceive. To be certain that they have not been deceived, and that they do not wish to mislead, we must ascertain, as far as possible, the nature and the quality of the facts proved; the quality and the person of the witness; and the testimony itself, by comparing it with the deposition of other witnesses, or with known facts. Vide Circumstances.
5. - 1. When we are called upon to rely on the testimony of another in order to form a judgment as to certain facts, we must be certain, 1st. That he knows the facts in question, and that he is not mistaken; and, 2d. That he is disposed to tell the truth, and has no desire to impose on those who are to form a judgment on his testimony. The confidence therefore, which we give to the witness must be considered, in the first place, by his capacity or his organization, and in the next, by the interest or motive which he has to tell or not to tell the truth. When the facts to which the witness testifies agree with the circumstances which are known to exist, he becomes much more credible than when there is a contradiction in this respect. It is true that until impeached one witness is as good as another; but when a witness is impeached, although he remains competent, he is not as credible as before. Vide Circumstances; Competency; Credibility.
6. - 11. As to the quality of the witnesses, it is a general rule that all persons way be witnesses. To this there are various exceptions. A witness may be incompetent, 1. For want of understanding. 2. On account of interest. 3. Because his admission is contrary to public policy. 4. For want of religious principles; and, 5. On account of infamy.
7. - §1. Persons who want understanding, it is clear, cannot be witnesses, because they are to depose to facts which they know; and if they have no understanding, they cannot know the facts. There are two classes of persons of this kind.
8. - 1. Infants. A child of any age capable of distinguishing between good and evil may be examined as a witness; and in all cases, the examination must be under oath or affirmation. 1 Phil. Ev. 19; 1 Const. R. 354. This appears to be the rule in England; though formerly it was held by some judges that it was a presumption of law that the child was incompetent when he was under seven years of age. Gilb. Ev. 144; 1 East, R. 422; 1 East, P. C. 443; 1 Leach, 199. When the child is under fourteen, he is presumed incapable until capacity is shown; 2 Tenn. Rep. 80; 19 Mass. R. 225; and see 18 John. R. 105; when he is over fourteen he may be sworn without a previous examination. 2 South. R. 589.
9. - 2. Idiots and lunatics. An idiot cannot be examined as a witness, but a lunatic, (q. v.) during a lucid interval, (q. v.) may be examined. A person in a state of intoxication cannot be admitted as a witness. 15 Serg. & Rawle, 235. See Ray, Med. Jur. c. 22, §300 to 311.
10. - §2. Interest in the event of the suit excludes the witness from examination, unless under certain circumstances. See article Interest. The exceptions are the cases of informers, (q. v.) when the statute makes them witnes-ses, although they may be entitled to a penalty; 1 Phil. Ev. 96; persons enti-tled to a reward, (q. v.) are sometimes competent; agents are also admitted in order to prove a contract made by them on the part of the principal, 1 Phil. Ev. 99; and see 1 John. Cas. 408; 2 John. Cas. 60; 2 John. R. 189; 13 Mass. R. 380; 11 Mass. R. 60; 2 Marsh. In 706 b; 1 Dall. R. 7; 1 Caines' R. 167. A mere trustee may be examined by either party. 1 Clarke, R. 281. An interested witness competency may be restored by a release. 1 Phil. Ev. 101. Vide, generally, 1 Day's R. 266, 269; 1 Caines' R. 276; 8 John. R. 518; 4 Mass. R. 488; 3 John. Cas. 82, 269; 1 Hayw. 2; 5 Halst. R. 297; 6 Binn. R. 319; 4 Binn. 83; 1 Dana's R. 181; 1 Taylor's R. 55; Bac. Ab. Evidence B; Bouv. Inst. Index, h. t.
11. - §3. There are some persons who cannot be examined as witnesses, because it is inconsistent with public policy that they should testify against certain persons; these are,
12. - 1. Husband and wife. The reason for excluding them from giving evidence, either for or against each other, is founded partly on their identity of interest, partly on a principle of public policy which deems it necessary to guard the security and confidence of private life, even at the risk of an occasional failure of justice. They cannot be witnesses for each other because their interests are absolutely the same; they are not witnesses against each other, because it is against the policy of marriage. Co. Litt. 6, b; 2 T. R. 265, 269; 6 Binn. 488. This is the rule when either is a party to a civil suit or action.
13. But where one of them, not being a party, is interested in the result, there is a distinction between the giving evidence for and against the other. It is an invariable rule that neither of them is a witness for the other who is interested in the result, and that where the husband is disqualified by his interest, the wife is also incompetent. 1 Ld. Raym. 744; 2 Str. 1095; 1 P. Wms. 610.
14. On the other hand, where the interest of the husband, consisting in a civil liability, would not have protected him from examination, it seems that the wife must also answer, although the effect may be to subject her husband to an action. This case differs very materially from those where the husband himself could not have been examined, either because he was a party or because he would criminate himself. The party to whom the testimony of the wife is essential, has a legal interest in her evidence; and as he might insist on examining the husband, it would, it seems, be straining the rule of policy too far to deprive him of the benefit of the wife's testimony. In an action for goods sold and delivered, it has been held that the wife of a third person is competent to prove that the credit was given to her husband. 1 Str. 504; B. N. P. 287. See 1 H. & M. 154; 11 Mass. 286; 1 Har. & J. 478; 1 Tayl. 9; 6 Binn. 488; 1 Yeates; 390, 534.
15. When neither of them is either a party to the suit, nor interested in the general result, the husband or wife is, it seems, competent to prove any fact, provided the evidence does not directly criminate, or tend to criminate, the other. 2 T. R. 263.
16. It has been held in Pennsylvania that the deposition of a wife on her death-bed, charging her husband with murdering her, was good evidence against him, on his trial for murder. Addis. 332. On an indictment for a conspiracy in inveigling a young girl from her mother's house, and she being intoxicated, procuring the marriage ceremony to be recited between her and one of the de-fendants, the girl is a competent witness to prove the facts. 2 Yeates, 114.
17. See, as to the competency of a wife de facto, but not de jure, Stark. Ev, pt. 4, p. 711. And on an indictment for forcible entry, the wife of the prosecutor was examined as a witness to prove the force, but only the force. 1 Dall. 68.
18. 2. Attorneys. They cannot be examined as witnesses as to confidential communications which they have received from their clients, made while the relation of attorney and client subsisted. 3 Johns. Cas. 198. See 3 Yeates, 4. Communications thus protected must have been made to him as instructions ne-cessary for conducting the cause, and not any extraneous or impertinent matter; 3 Johns. Cas. 198; they must have been made to him in the character of a counsel and not as a friend merely; 1 Caines' R. 15 7; they must have been made while the relation of counsel and client existed, and not after. 13 John. Rep. 492. An attorney may be examined as to the existence of a paper entrusted to him by his client, and as to the fact that it is in his possession, but he cannot be compelled to produce it, or disclose its date or contents. 17 Johns. R. 335. See 18 Johns. R. 330. He may also be called to prove a collateral fact not entrusted to him by his client; as to prove. his client's handwriting. 19 Johns. R. 134: 3 Yeates, 4. He is a competent witness for his client, although his judgment fee depends upon his success; 1 Dall. 241; or he expects to receive a larger fee from his client if the latter succeeds. 4 S. & R. 82. In Louisiana, the reverse has been decided. It is there held that an attorney cannot become a witness for his client in a cause in which he was employed, by renouncing his fee, and having his name struck off from the record, in that case. 3 N. S. 88. Vide Confidential Communications.
19. - 3. Confessors. In New York it has been held that a confessor could not be compelled to disclose secrets which he had received in auricular confession. City Hall Rec. 80 n. Vide Confessor; Confidential Communications.
20. - 4. Jurors. A juror is not competent to prove his own or the conduct of his fellow jurors to impeach a verdict they have rendered. 5 Conn. R. 348. See Coxe, R. 166, and article Grand Jury. And a judge in a cause which is on trial before him cannot be a witness, as he cannot decide on his own competency, nor on the weight of his own testimony, compared with that of another; 2 Mart. R. N. S. 312; 1 Greenl. Ev. §364.
21. - 5. Slaves. It is said that a slave could not be a witness at common law because of the unbounded influence his master had over him. 4 Dall. R. 145, note 1; but see 1 St. Tr. 113 Macnally's Ev. 156. By statutory provisions in the slave states, a slave is generally held incompetent in actions between white persons. See 7 Monr. R. 91; 4 Ham. R. 353; 5 Litt. R. 171; 3 Harr. & John. 97; 1 McCord, R. 430. In New York a free black man is competent to prove facts happening while he was a slave. 1 John. R. 508; see 10 John. R. 132.
22. - 6. A party to a negotiable instrument, is not allowed to give evidence to invalidate it. 1 T. R. 300. But the rule is confined to negotiable instruments. 1 Bl. R. 365. This rule does not appear to be very firmly established in England. In the state courts of some of the United States it has been adopted, and may now be considered to be law. 2 Dall. R. 194; ld. 196; 2 Binn. R. 154; 2 Dall. R. 242; 1 Cain. R. 258, 267; 2 Johns. R. 165; Id. 258; 1 John. R. 572; 3 Mass R. 559; Id. 565; Id. 27; Id. 31; 1 Day, R. 17; 6 Pet. 51; 8 Pet. 12; 5 Greenl. 374; 1 Bailey, 479; 2 Dall. 194. But flee 16 John. 70; 8 Wend. 90; 20 John. 285. The witness may however testify to subsequent facts, not tending to show that the instrument was originally invalid. Peake's N. P. C. 6. See 2 Wash. 63; 1 Hen. & Munf. 165, 166, 175; 1 Cranch, R. 194.
23. - §4. When the witness has no religious principles to bind his conscience, the law rejects his testimony; but there is not such defect of religious principles, when the witness believes in the existence of a God, who will reward or punish in this world or that which is to come. Willes' R. 550. Vide the article Infidel where the subject is more fully examined and Atheist; Future state.
24. - §5. Infamy (q. v.) is a disqualification while it remains.
27. - 2. In criminal cages, there are several instances where two witnesses at least are required. The constitution of the United States, art. 3, s. 3, provides that no person shall be convicted of treason, unless on the testimony of two witnesses to the same overt act, or on confession in open court. In cases of perjury there must evidently be two witnesses, or one witness, and such circumstances as have the effect of one witness; for if there be but one witness, then there is oath against oath, and therefore uncertainty.
28. A witness may be compelled to attend court. In the first place a subpoena requiring his attendance must be served upon him personally, and on his neglect to attend, an attachment for contempt will be issued. See, generally, Bouv. Inst. Index, h. t.