§ 548. In the first place, as to considerations arising from benefit or injury. The principal requisite, and that which is the essence of every consideration, is, that it should create some benefit to the party promising, or some trouble, prejudice, or inconvenience to the party to whom the promise is made; wherever, therefore, any injury to the one party, or any benefit to the other party springs from a consideration, it is sufficient to support a contract.1 But in order to render an injury to the by the civilians into four species: 1. Do, ut des; as, when I give money or goods, on a contract that I shall be repaid money or goods for them again. Of this kind are all loans of money upon bond, or promise of repayment; and all sales of goods, in which there is either an express contract to pay so much for them, or else the law implies a contract to pay so much as they are worth. 2. The second species is, facio, ut facias; as, when I agree with a man to do his work for him, if he will do mine for me; or if two persons agree to marry together, or to do any other positive acts on both sides. Or, it may be to forbear on one side on consideration of something done on the other; as, that in consideration A., the tenant, will repair his house, B., the landlord, will not sue him for waste. Or, it may be for mutual forbearance on both sides; as, that in consideration that A. will not trade to Lisbon, B. will not trade to Marseilles, so as to avoid interfering with each other. 3. The third species of consideration is, facio, ut des; when a man agrees to perform any thing for a price, either specifically mentioned, or left to the determination of the law to set a value to it. And . when a servant hires himself to his master for certain wages or an agreed sum of money; here the servant contracts to do his master's service, in order to earn that specific sum. Otherwise, if he be hired generally; for then he is under an implied contract to perform this service for what it shall be reasonably worth. 4. The fourth species is, do, ut facias; which is the direct counterpart of the preceding; as, when I agree with a servant to give him such wages upon his performing such work; which, we see, is nothing else but the last species inverted; for servus facit, ut herus det, and herus dot, ut servus facial." 2 Black. Comm. 444.

1 Com. Dig. Action on the Case, Assumpsit, B. 1; Forth v. Stanton, 1 Saund. 210, note 1, 2; Miller v. Drake, 1 Caines, 45; Powell v. Brown, 3 Johns. 100; Forster v. Fuller, 6 Mass. 58; Overstreet v. Philips, 1 Litt. 123; Lent v. Padelford, 10 Mass. 230; Train v. Gold, 5 Pick. 380; Met-calTs Digest, Agreement, and cases cited; Williamson v. Clements, 1 promisee a good consideration, it must be an injury upon entering into the contract, and not from a breach of it.1 It is not necessary that the consideration and promise should be equivalents in actual value, for it would be impossible ever precisely to determine whether in a given case the consideration was adequate, without a psychological investigation into the motives of the parties. Besides, if no contract were good but those which were apparently of equal benefit to both parties, probably very few contracts which are made would be legally valid. Each party to a contract may ordinarily exercise his own discretion, as to the adequacy of the consideration; and if the agreement be made bond fide, it matters not how insignificant the benefit may apparently be to the promisor,2 or how slight the inconvenience or damage appear to be to the promisee; provided it be susceptible of any legal estimation.3

Taunt. 523; Gully v. The Bishop of Exeter, 10 B. & C. 606; Violett v. Patton, 5 Cranch, 142; Kirwan v. Kirwan, 2 Cr. & M. 623; Hubbard v. Coolidge, 1 Met. 93. Tt is a good consideration for a promise for extra pay for services to mariners, that part of the crew having left the ship, whereby it became dangerous for the rest to go on with it, they nevertheless agreed to proceed for the increased remuneration. • They were not bound to proceed, and doing so was a detriment to them. Hartley v. Ponsonby, 7 El. & B. 872 (1857). So where the plaintiff, owning certain bills in the hands of the defendant, consented that the defendant should retain them for the purpose of getting them discounted, this was held a sufficient consideration for the defendants promise to dispose of the proceeds in a certain manner, if he succeeded in getting the bills discounted. Hart v. Miles, 4 C. B. (n. 8.) 371 (1858). See also, as to benefit and injury as a consideration, Shadwell v. Shadwell, 9 C. B. (n. s.) 159 (1860); Foster v. Phaley, 35 Vt. 303 (1862); Dorwin v. Smith, ib. 69; Perry v. Buckman, 33 Vt. 7 (1860).

1 Lord Campbell, C. J., in Gerhard v. Bates, 2 El. & B. 476 J 20 Eng. Law & Eq. 135.

2 Any advantage to the promisor, however slight, is a sufficient consideration. Hart v. Miles, 4 C. B. (n. s.) 371 (1858); Rutgers v. Lucet, 2 Johns. Cas. 92; Clark v. Gaylord, 24 Conn. 484; Spangler v. Springer, 22 Penn. St. 458; Clark v. Sigourney, 17 Conn. 511; Harlan v. Harlan, 20 Penn. St. 303.

3 Com. Dig. Action on the Case, Assumpsit, B.; Davis v. Morgan, 4 B. & C. 8. See post, § 271; Pierce v. Fuller, 8 Mass. 223; Bragg v. Tanner, cited Cro. Jac. 397; Lawrence v. McCalmont, 2 How. 426; Hubbard v. Coolidge, 1 Met. 84; Clark v. Sigourney, 17 Conn. 511; Sanborn v. French, 2 Fost. 246; Whittle v. Skinner, 23 Vt. 532; Bainbridge v. Firmstone,

Thus a promise to pay the bond of a third person, if the obligee will go before a magistrate, and make oath that it was rightly read to the obligor before he executed it, is binding, because u the travail of coming before the mayor is a very good consideration.": So, also, proof of a debt is a sufficient consideration for a promise to pay, because it is a charge to the plaintiff.2 And a promise to pay a certain sum of money, on condition that the plaintiff call for it at a particular time, is binding; because the condition is an inconvenience to the plaintiff.3 So, a promise by an uncle to pay his nephew an annuity in consideration of, or as an inducement to, his marriage with a person to whom he was already engaged, is founded upon good consideration, and is binding.4 So, also, a promise in consideration of receiving a certain sum of money, to pay the same into court, is good; because the party receiv-ing'the money had the benefit of it.5 So, also, where, in order to facilitate the making of an agreement, for which there was sufficient consideration between A. and C, B., who received no benefit himself, became a party thereto, it was held, in an action against B., that, as the agreement was such as A. would not have made, unless B. had consented to be a party, there was a sufficient consideration for B. to promise.6 Again, where the defendant promised to the plaintiff to pay him 1000, if the latter would surrender to him a letter, written by 0., then deceased, by means of which the defendant was enabled to determine certain controversies, and obtain a large portion of O.'s effects, it was held that there was sufficient consideration to support the promise.1 So, also, an agreement by a creditor to take less than the face of his demand, upon receiving security for the amount to be paid, is founded on a sufficient consideration, growing out of the additional security.2 So, too, an agreement to allow the pastor of a church a credit on property not paid for, in consideration of his age, long services, and resignation as pastor, is valid.3