The opinion of the court was delivered by
Ro&ers, J.
' It is very difficult to resist the belief, that the assignment of Phinney to Hanson was made for the express purpose of enabling Hanson to make a set-off, in the suit brought before the justice by Tracey against Hanson; the claim as then understood to be supported, if necessary, by the oath of Phinney. It therefore came within the principle ruled in Post v. Avery, 5 Watts & Serg. 510; Leiper v. Pierce, 6 Watts & Serg. 555; Patterson v. Reed, 7 Watts & Serg. 144, and the Reading Railroad v. Johnson, Id. 317. A colourable assignment, to make a legal plaintiff a witness, does not divest his interest, and every assignment is deemed colourable until the contrary appears. It must be conceded that the cases cited seem to admit that there may be cases where the assignor of a chose in action, although plaintiff on the record, may be a witness, where it manifestly appears that the assignment was made in the usual course of business, and without any intention, either expressed or understood, at the time of supporting the claim by the oath of the assignor. It is possible such a case may occur; but the legal presumption, which is adverse to the admission of such testimony, must be rebutted by the most overwhelming proofs. Not the slightest *176doubt should be suffered to remain, that at the time of the contract there was no such intention whatever entertained, no such necessity supposed to exist. We deem it of no consequence at what stage of the cause the witness is offered, whether to maintain the whole cause, or to supply an indispensable link in the chain of. testimony, or be corroborative evidence merely; whether the assignment be made for a full or at an undervalue, or to be used as a set-off, which is in the nature of a cross action, or with a view of commencing suit upon it. Indeed, it should not be permitted that the assignor of a chose in action shall support it by his own oath. In that respect the creditor and debtor ought, in all justice, to be placed on precisely the same footing; and this, I conceive, is the result of the reasoning of Mr. Justice Kennedy in Patterson v. Reed, to which I fully subscribe. As the debtor is not allowed to invalidate the debt by his own testimony, why should the creditor be vested, by means of an assignment most usually made for that purpose, with a greater privilege; particularly when the experience of thirty years has afforded such abundant evidence of tire extent to which it may be abused? Both should be allowed to testify, or neither. It is true, that sometimes an honest claim may be lost for want of the oath of the party, but this is a trifling evil, compared with the temptation to peijury and fraud to which tire former doctrine necessarily led.
Judgment affirmed.