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Civil law. An agreement by which a person appointed to his creditor, a certain day, or a certain time, at which he pro-mised to pay; or it maybe defined, simply. an agreement by which a person promises a creditor to pay him.

When a person by this pact promises his own creditor to pay him, there arises a new obligation which does not destroy the former by which he was already bound, but which is accessory to it; and by this multiplicity of obligations the right of the creditor is strengthened. Poth. Ob. Pt. 2, c. 6, s. 9.

There is a striking conformity between the pactum constitutae pecuniae, as above defined, and our indebitatus assumpsit. The pactum constitutae pecuniae was a promise to pay a subsisting debt whether natural or civil; made in such a manner as not to extinguish the preceding debt, and introduced by the praetor to obviate some formal difficulties. The action of indebitalus assumpsit was brought upon a promise for the payment of a debt, it was not subject to the wager of law and other technical difficulties of the regular action of debt; but by such promise, the right to the action of debt was not extinguished nor varied. 4 Rep. 91 to 95; see 1 H. Bl. 550 to 655; Doug. 6, 7; 3 Wood. 168, 169, n. c; 1 Vin. Abr. 270; Bro. Abr. Action sur le case, pl. 7, 69, 72; Fitzh. N. B. 94, A, n. a, 145 G; 1 New Rep. 295; Bl. Rep. 850; 1 Chit. Pl. 89; Toull. Dr. Civ. Fr. liv. 3, t. 3, c. 4, u. 388, 396.