Tatum's Executors v. Lofton & Anderson

I am perfectly satisfied that the witness should be compelled to give testimony. There can be no reasonable doubt but that the rule, which is the foundation of that compulsion, is supported by the principles of justice. But independent of this consideration, a train of well-settled adjudications has put the question to rest. The books do not recognize any such distinction as is contended for by the gentleman who appears for the defendants. The witness is not coerced to give his testimony, because he happens to have agreed to become an evidence; but because, as there once was a period when the plaintiff had a right to the benefit of his testimony, the witness shall not be permitted, by his own act, or the act of the party against whom he is called, to deprive him of that right. The rule is, however, different, where the interest is occasioned by the act of law, or the party who requires the benefit of the testimony. But where it arises, as before remarked, by the act of the witness, it is a wrong in the witness, of which, from a well-known rule of law, he shall not take advantage. Let him be sworn.