Vansciver v. Bolton, 2 Dall. 114 (Pa. 1790)

Certiorari to remove the judgment of a Justice of the Peace. As cause for reversing the judgment, Levy shewed, by the Defendant's affidavit, that the debt had been proved before the Justice by the Plaintiff's oath alone. Howell objected, that this was not sufficient, as the Plaintiff might have sworn to his books; and, at all events, the exception to the judgment cannot be supported by the mere shewing of the Defendant's affidavit.

McKean, Chief Justice—The oath of the interested party cannot singly be admitted to maintain his demand: nor, is it merely upon a Plaintiff's oath, that an original entry in his books is received in our courts as evidence; since that, when allowed its utmost latitude, proves nothing more than the sale and delivery of the goods.

With respect to the mode of establishing the exception to the judgment, the affidavit of the Defendant, though not conclusive, must at least be deemed sufficient, for throwing the onus probandi, if other evidence was produced, upon his adversary.