This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
Performance by one party, has two results: (1) It discharges the party so performing from further liability under the contract.1 Thus a common carrier who contracts only to deliver to the next carrier discharges its liability by so doing, no matter what the fate of the goods shipped.2 (2) Performance gives to the party performing the right to enforce the contract against the adversary party who has not fully performed, when performance from him is due. If the contract has not already been broken by the adversary party so as to discharge it, the party performing may perform without the consent or acquiescence therein of such adversary party.3 Whether a contract has been performed or not is a question of fact.4
1 Courteen v. Kanawha Dispatch, 110 Wis. 610; 55 L. R. A. 182; 86 N. W. 176.
2 Courteen v. Kanawha Dispatch, 110 Wis. 610; 55 L. R. A. 182; 86 N. W. 176.
3 Central Coal & Coke Co. v. Good. 120 Fed. 793.
4 Lincoln v. Orthwein, 120 Fed. 880; United States, etc., Co. v. Sprinkler Co., 84 Mo. App. 204; Charley v. Potthof, 118 Wis. 258; 95 N. W. 124.