To the credibility of any witness it is always requisite that he be disinterested, that his own cause be not involved in that of the person who stands at the bar, that he has no prospect of advancing his fortune, clearing his reputation, or securing his life. For it is made too plain by daily examples, that interest will prevail over the virtue of most men, and that it is not safe to believe those who are strongly tempted to deceive.
There are cases, my lords, where the interest of the person offering his evidence is so apparent, that he is not even admitted to be heard; and any benefit which may possibly be proposed, is admitted as an objection to evidence, and weakens it in a measure proportionate to the distance of the prospect and the degree of profit.
Such are the rules hitherto followed in criminal proceedings, the violation of which has been always censured as cruelty and oppression, and perhaps always been repented even by those who proposed and defended it, when the commotions of party have subsided, and the heat of opposition and resentment has given way to unprejudiced reflection.
Of these rules, my lords, it is not necessary to produce any defence from the practice of distant nations, because it is sufficient in the present case, that they are established by the constitution of this country, to which every Briton has a right to appeal; for how can any man defend his conduct, if having acted under one law, he is to be tried by another?
Let us, therefore, my lords, apply these rules to the present bill, and inquire what regard appears to have been paid to them by the commons, and how well we shall observe them by concurring in their design.
With respect to the first, by which it is required, that there be a known and manifest crime, it does not appear to have engaged the least attention in the other house; for no fact is specified in the bill, upon which a prosecution can be founded, and, therefore, to inquire after evidence is somewhat preposterous; it is nothing less than to invite men to give their opinion without a subject, and to answer without a question.
It may be urged, indeed, that there is a universal discontent over the whole nation; that the clamour against the person mentioned in the bill, has been continued for many years; that the influence of the nation is impaired in foreign countries; that our treasury is exhausted; that our liberties have been attacked, our properties invaded, and our morals corrupted; but these are yet only rumours, without proof, and without legal certainty; which may, indeed, with great propriety give occasion to an inquiry, and, perhaps, by that inquiry some facts may be ascertained which may afford sufficient reasons for farther procedure.
But such, my lords, is the form of the bill now before us, that if it should pass into a statute, it would, in my opinion, put a stop to all future inquiry, by making those incapable of giving evidence, who have had most opportunities of knowing those transactions, which have given the chief occasion of suspicion, and from whom, therefore, the most important information must naturally be expected.
The first requisite qualification of a witness, whether we consult natural equity and reason, or the common law of our own country, is disinterestedness; an indifference, with regard to all outward circumstances, about the event of the trial at which his testimony is required. For he that is called as a witness where he is interested, is in reality giving evidence in his own cause.
But this qualification, my lords, the bill now before us manifestly takes away; for every man who shall appear against the person into whose conduct the commons are inquiring, evidently promotes, in the highest degree, his own interest by his evidence, as he may preclude all examination of his own behaviour, and secure the possession of that wealth which he has accumulated by fraud and oppression, or, perhaps, preserve that life which the justice of the nation might take away.