GOODE, J.
(after stating the facts).
Plaintiff was defeated on the theory there was no consideration for Walker’s promise to pay the cost of replastering the ceilings, because plaintiff was under a contract with Gerhard to do so if the plaster first put on crumbled, and hence in agreeing with Walker and performing under the agreement, he neither undertook to do nor did more than was within the scope of his obligation to Gerhard. It is important at the outset to 'determine what this obligation was. We hold it was to do “a strictly first-class job to the satisfaction of the commissioner,” and guarantee the plastering upon the ceilings would remain in place two years. The job as first *530done was concededly a failure and to perform Ms contract it was incumbent on plaintiff to do it over so as to make it first-class. His obligation was not limited to Ms guaranty in the sense that be bad an option to respond in damages on Ms guaranty or make the job first-class. It'is true be might have refused to replaster, and perhaps as the contract was for personal services, he could not have been forced to do so, and Ger-hard’s only remedy against him would have been in damages. But if these things are true, it does not follow plaintiff would have performed his obligation by paying damages, though he might have discharged his legal liability. We are no friends to the doctrine which finds a consideration for a promise to pay additional compensation for the performance of a contract, on the theory that the party to the contract was only bound to perform or pay damages at his option, and, therefore, the promise of further compensation to induce him to perform is good, because it secures to the promisee the service he wants instead of leaving him to his remedy in damages. As to this phase of the subject we agree with the views expressed in Harriman, Contracts (2 Ed.), sections 117 to 125 inclusive and 8 Harvard Law Rev., pp. 27 to 30. But neither are we friendly to highly strained technical rules in regard to the consideration of contracts, whereby agreements which parties understood to be complete and valid contracts are annulled. In this matter, more than others, it is important to keep the law in accord with the understanding of the people; and it is our opinion that hardly any man, except an astute lawyer, if placed as plaintiff was, would doubt he had a good contract with Walker to pay the cost of replastering. It is a fair inference from the circumstances in proof that plaintiff assented to Walker’s proposal for him to replaster at Walker’s expense. If this was true, there were mutual promises which, according to reason and some authority, would constitute a. contract binding on both plaintiff and *531Walker, or defendant, whom the latter represented. [Langdell in 19 Harv. Law Rev. 496; Harriman, Contracts, sec. 94.] Whether plaintiff accepted the proposal in words or not, he accepted by conduct to Walker’s knowledge and replastered forthwith pursuant to the arrangement. If the agreement was unilateral in the first instance, according to the general 'doctrine it became binding on defendant when plaintiff had done the work and incurred expense under it. [Underwood Typewriter Co. v. Century Bldg. Co., 119 S. W. 400.] When those two propositions of law are to be applied to a case where the new contract deals Avith the same subject-matter as a previous contract between one of the parties and another person, the courts of the United States for the most part do not treat the new mutual promises, or even performance under them, as sufficient consideration for the agreement, if the performing party already was under an obligation to do the identical thing. In such instances it is conceived there is no detriment to him from the new agreement, and whatever benefit, if any, accrues to the other party to said agreement is held not an adequate consideration. Plaintiff’s original contract did not bind him to use Acme cement in replastering, but. he could choose among several kinds. The witnesses testified nothing was said about what material he should repair with; but likely he and Walker understood the replastering was to be done with Acme. If this were true, plaintiff’s obligation was more restricted and onerous than the one he was under with Gerhard and there could be no doubt that it was supported by a consideration. [Corrigan v. Detsch, 61 Mo. 290.] As the right to deduce this inference from the evidence is somewhat dubious, we will assume Walker’s proposal meant plaintiff might use any of the cements mentioned in the specifications. Considered in this aspect the case strikes us, after much search among the books, as one of first impression in respect of the pos*532ture of affairs when Walker’s promise was given. There are numerous decisions by the courts of this country that a promise given to a stranger by one party to a contract to do what he was already bound to do, is no consideration for an agreement by the stranger to pay for the performance. [1 Parsons, Contracts (9 Ed.), p. 478, and note; Harriman, Contracts (2 Ed.), sec. 122; Walds-Pollock, Contracts (3 Ed.), p. 209, note 19.] The rule is the other way in England and in a few cases in this country. [Abbott v. Doane, 163 Mass. 433; 34 L. R. A. 1 and annotations.] An examination of the cases in which this proposition has been decided, shows the underlying policy of the rule is to prevent persons from extorting compensation beyond what was agreed upon at first, for complying with their contracts or discharging a duty imposed by law. The spirit of the ¡rule is found in the maxim that a man will not be suffered to take advantage of his own wrong, and properly applied it is a wholesome rule. If allowed to control the decision of a case like the one before us, the reason and policy of it are forgotten, and its application becomes not only arbitrary, but unjust and mischievous. Considered from a commercial point of view, defendant had a strong motive to get the work done over without the faults of the plastering becoming generally known, as would happen if there was a prolonged dispute or litigation. It cannot be said this motive amounted to a consideration, for the financial benefit defendant would obtain from having the subject dropped, would be indirect and not accrue from its agreement with plaintiff, to whom it was not liable for defects in the plaster. But let us look closely at the situation when the agreement was made, and the effect of it on plaintiff’s conduct. It had not yet been settled what caused the plastering to drop, or whether the circumstances were such as to constitute a breach of plaintiff’s contract. The question of where the fault was and where the responsibility rested were under discussion. Conceding *533the conclusion would have been reached that plaintiff was bound to replaster, it would then have been for him to decide whether he would use Acme or some other plaster in the work. Now granting the arrangement with Walker did not bind plaintiff to use Acme, Walker’s conduct in cutting off further investigation of said matters and directing plaintiff to replaster at once, at least caused plaintiff to waive a further examination into his obligation and responsibility and further deliberation upon whether he would replaster with Acme cement or some other. On deliberation plaintiff might have decided to use a different plaster instead of making a second experiment with a kind that had failed, and in point of fact his re-use of Acme appears to have entailed on him the-task of replastering a second time at his own loss. But the essential fact is that while plaintiff’s obligation was under examination and in controversy, the matter was brought to a close by the agreement between plaintiff and defendant. The case resembles Good Fellows v. Campbell, 17 R. I. 402, where it appeared a sister who had been named as beneficiary of a certificate of insurance, while ignorant of the fact, agreed the insurance money might be distributed among all her brother’s heirs, including herself. She was held bound by the agreement for this reason, among others: That who was entitled to the fund was uncertain when the agreement was made, and the parties agreed in consideration of mutual chances. [See l. c. 405 and cases cited; also Harriman, Contracts, sec. 109.] The situation with which we are dealing is not that of a party attempting to extort additional pay for doing something he had bound himself to do, for plaintiff was not attempting to evade his obligation, but to ascertain it and settle on how to perform it. We think there was a detriment to plaintiff in agreeing with Walker and performing the agreement, and if there was, the arrangement became a contract supported by a valid consideration. [Strode v. Transit Co., 197 Mo. l. c. *534622; Underwood Typewriter Co. v. Century Bldg. Co., supra.] We say nothing- about whether the repairing was done for reasonable prices, as that is a matter for the triers of the fact.
The judgment is reversed and the cause remanded.
All concur.