CAUTION. - Surety, which is generally a measure aimed at preventing harm, in legal relations consists of a means provided by the parties or by law: to make secure one who is exposed to a prejudice, not actual but possible; to ensure the fulfillment of an already existing obligation; to guarantee the exercise of certain functions. Surety falls among the means protecting the creditor's right insofar as it provides a guarantee that strengthens the obligatory bond or that otherwise ensures the fulfillment of the obligation.
Surety has an existence subordinate to the right it secures, and therefore has an accessory character, and only upon the occurrence of the harm does it serve to repair it. It may be required by law or by the judge, or agreed upon by the parties; it may be furnished by the obligor himself or by another person on his behalf. Surety may be provided in various ways: through the establishment of real rights over movable things (pledge), or over immovable things (mortgage), or through the establishment of obligations whereby another debtor (suretyship) is added to the principal obligor (suretyship). There are also procedural sureties, which are not given properly to strengthen the protection of a right, but rather (generally by order of the judge) as a guarantee of the execution of a measure, even a future one, of the judge, or to obtain from the judge a favorable measure that could prove harmful to others if a surety were not provided.
The CIC refers fully to what is established by the civil law of its own territory (can. 1529) for all the modalities of surety in contractual matters; moreover it determines the individual cases of surety to be provided in trials: cann. 1626, 1631, 1674, 1907 § 2, 1909 § 1, 1917 § 1. By virtue of can. 137, clerics are forbidden to give suretyship even with their own goods.
In canon law, the promises that contracting parties must make in order to obtain dispensation from the matrimonial impediments of disparity of cult or of mixed religion are also called surety (v. DISPARITÀ DI CULTO).
Bibliography
Elio Gambari