I I IGNORANCE OF IMPOSSIBILITY AS TO CONSIDERATION 687 enter into a contract. A is bound while B is free ; but in the ordinary case, where no impossibility of performing the agreement intervenes, the law does not deny A the right to expect that if he goes ahead with the contract upon the affirmance thereof by B, the latter will carry out his side of the agreement. Professor Williston, defining what constitutes sufficient considera- tion in a bilateral contract, says: "Mutual promises each of which assures ^^ some act or forbearance that will be, or apparently may be, detrimental to the promisor or bene- ficial to the promisee, and neither of which is rendered void by any rule of law other than that relating to consideration, are sufficient considera- tion for one another." ^^ Apply this test to our A B case, and the result appears to be that there is no act of any nature or quaUty whatsoever that is " assured." Professor Ballantine would modify the above definition and rather state it thus : "Consideration is something of possible value given or undertaken to be given in return for something promised;" and he adds, "The test of the consideration is the possible value of the thing promised and not the effect of the promise itself." ^^ That is to say, consideration is not to be sought in the -promises in fact, or in the actual performances of the promises, but in a prom- ised performance, or a prospective value bargained for. Of course anyone can "undertake to give something of possible value," even though he has no idea of actually doing so, or though he well knows at the time he promises that the law will make it impossible for him to execute his undertaking. So, while this theory of consideration offers hospitahty to the outcast voidable contracts (those of infants, insane or drunken persons, or others whose promises are for any reason performable only at their own option) ^^ it seems to me that it justifies calling our A B case a "contract" only for the same reason that Professor Ames' theory of considera- tion would allow of this, viz., in the one case as in the other one is dealing in reality with a "lip" promise. Anyone who undertakes
- Italics are mine.
" 27 Harv. L. Rev. 527, 528. " 28 Harv. L. Rev. 133. '* II Mich. L. Rev. 429, 430; 28 Harv, L. Rev. 130; see also Professor Williston in 27 Harv. L. Rev. 528.
