§ 11. Every contract is founded upon the mutual agreement of the parties; and that agreement may either be formally stated in words, or committed to writing, or it may be a legal inference, drawn from the circumstances of the case, in order to explain the situation, conduct, and relations of the parties. When the agreement is formal, and stated either verbally or in writing, it is usually called an express contract. When the agreement is matter of inference and deduction, it is called an implied contract. Both species of contract, are, however, equally founded upon the actual agreement of the parties, and the only distinction between them is in regard to the mode of proof, which belongs to the law of evidence. In an implied contract, the law only supplies that which, although not stated, must be presumed to have been the agreement intended by the parties.3 It is on a similar ground that if the contract is silent as to time, a reasonable time is always intended.4

1 The learned author is here speaking, of course, of contracts at common law, and not of such as by some statute, as the statute of frauds for instance, must be in writing.

2 Skynner, C. B., in delivering the opinion of the court, in Rann v. Hughes, cited in the note to 7 T. R. 350, says, "All contracts are, by the law of England, distinguished into agreements by specialty and agreements by parol, nor is there any such third class, as some of the counsel have endeavored to maintain, as contracts in writing. If they be merely written, and not specialties, they are parol, and a consideration must be proved." See, however, Stackpole v. Arnold, 11 Mass. 30, where the late Chief Justice Parker says, " There are three classes of contracts; namely, specialties, written contracts not under seal, and parol or verbal contracts." This classification, however, was only employed in relation to the particular point before the court, and does not agree with the established authorities. Cook v. Bradley, 7 Conn. 57; People v. Shall, 9 Cow. 778; Burnet v. Bisco, 4 Johns. 235; Thacher v. Dinsmore, 5 Mass. 301: Brown v. Adair, 1 Stew. & Port. 51. See 20 Am. Jur. 4.

3 2 Black. Comm. 443. In the Roman law, implied contracts are entitled, "Obligationes quasi ex contractu." Church v. The Imperial Gas Light Co., 6 Ad. & El. 859. 4 Ford v. Colesworth, 9 B. & S. 559.

§ 12. The law always presumes such agreements to have been made as justice and reason would dictate, and assists the parties to any transaction in an honest explanation of it.1 Or, as sometimes stated, the law implies a promise, wherever there is an antecedent legal duty and obligation;2 or a promise may be implied wherever a relation exists between two parties which involves the performance of certain duties by one of them, and a payment therefor by the other.3 But a promise will not be implied, contravening the express declarations of the party charged, made at the time of the supposed agreement,4 unless such declarations be at variance with some legal duty, and then the law will imply a promise to perform that duty; as where a husband wrongfully expels his wife or minor child from his house, and declares that he will not be responsible for articles furnished to them, the law sets his declaration at naught, and compels him to pay for necessaries furnished to them.5 Wherever a party avails himself of the benefit of services done for him, although without his positive authority or request, the law supplies the formal words of contract and presumes him to have promised an adequate compensation;6 as where a person buys an article without stipulating for the price, he is presumed to have undertaken to pay its market value; or where he allows another to do any work or make any article for him, he impliedly binds himself to pay what it is worth;7 or where he holds the money of another as trustee or of one, - in which case, as credit would have been given but to the inviter, he alone would be liable.1 So, too, an agent who has collected money for his principal, even upon an illegal contract, is under an implied obligation to pay the same to his principal.2

1 Chief Justice Marshall, in Ogden v. Saunders, 12 Wheat. 341, says, "A great mass of human transactions depend upon implied contracts, which are not written, but grow out of the acts of the parties. In such cases, the parties are supposed to have made those stipulations which, as honest, fair, and just men, they ought to have made." As where the government takes private property for public uses. United States v. Russell, 13 Wall. 623.

2 Kelby v. Andrew, 43 Miss. 342; Clutterbuck v. Coffin, 3M.&G. 842.

3 See Morgan v. Ravey, 6H.&N. 265.

4 Whiting v. Sullivan, 7 Mass. 107; Worthen v. Stevens, 4 Mass. 448; 3 Starkie, Ev. 1763; Selway v. Fogg, 5 M. & W. 83.

5 Robison v. Gosnold, 6 Mod. 171; Harris v. Morris, 4 Esp. 42; 2 Kent, Comm. 125, 126; Thompson v. Hervey, 4 Burr. 2178; Angel v. McLellan, 16 Mass. 31; Van Valkinburg v. Watson, 13 Johns. 480.

6 Abbot v. Hermon, 7 Greenl. 121; Brackett v. Norton, 4 Conn. 524. Fisher v. School Dist. No. 17, 4 \Cush. 494.

7 The law does not so readily imply a contract to pay for labor and serbailee, the law supposes a promise to restore it. So if services are rendered gratuitously, and without any agreement for compensation, express or implied, no action lies on a quantum meruit, however beneficial the service to the defendant.1 So, also, where a person engages to do any work or perform any service, he is understood to engage that he has sufficient skill and ability to fulfil his contract,2 and, also, that he will use all the means necessary to accomplish it.3 So, also, if a party of friends meet to dine at a tavern, and give a joint order for dinner, and after dinner all but the plaintiff depart without paying, and the plaintiff pay for all. he may maintain an action against the others on an implied promise by them to pay their several proportions of the joint liability.4 So, also, each party would be responsible to the innkeeper on an implied promise to pay the reckoning, unless it were known that all were guests vices rendered by one's relatives, or for board furnished a. relative, as in other cases where no such relation exists. See Hartman's Appeal, 3 Grant, 271; Butler v. Slam, 50 Penn. St. 456; Duffey v. Duffey, 44 Penn. St. 399; Perry v. Perry, 2 Duv. 312; Smith v. Milligan, 43 Penn. St. 107; Updike v. Titus, 2 Beasl. 151. It raises no implied promise in a parent to pay a child who remains in his family after he is of age; the child must prove an express promise. See Ridgway v. English, 2 Zab. 409; Williams v. Hutchinson, 3 Comst. 312; Robinson v. Cushman, 2 Denio, 152. But an agreement by the father that his son should be paid out of his estate, after his death, is valid. Updike v. Ten Broeck, 3 Vroem, 105. This rule applies to adopted children. Lunay v. Vantyne, 40 Vt. 501 (1868). If one performs labor for another, merely with the hope and expectation of receiving a legacy from him, it is said there is no implied contract to pay for such services, if no legacy be given in the will. Davison v. Davison, 2 Beasl. 246; Kennard v. Whitson, 1 Houst. 36. But special circumstances may modify this doctrine. See Robinson v. Raynor, 28 N. Y. 494.