binding promise。 We are not seeking for the legal effects of a contract； but for the possible contents of a promise which the law may or may not enforce。 We must therefore only consider the question what can possibly be promised in a legal sense； not what will be the secondary consequence of a promise binding； but not performed。
An assurance that it shall rain to…morrow； /1/ or that a third person shall paint a picture； may as well be a promise as one that the promisee shall receive from some source one hundred bales of cotton； or that the promisor will pay the promisee one hundred dollars。 What is the difference in the cases？ It is only in the degree of power possessed by the promisor over the event。 He has none in the first case。 He has equally little legal authority to make a man paint a picture； although he may have larger means of persuasion。 He probably will be able to make sure that the promisee has the cotton。 Being a rich man； he is certain ＇299＇ to be able to pay the one hundred dollars； except in the event of some most improbable accident。
But the law does not inquire； as a general thing； how far the accomplishment of an assurance touching the future is within the power of the promisor。 In the moral world it may be that the obligation of a promise is confined to what lies within reach of the will of the promisor （except so far as the limit is unknown on one side； and misrepresented on the other）。 But unless some consideration of public policy intervenes； I take it that a man may bind himself at law that any future event shall happen。 He can therefore promise it in a legal sense。 It may be said that when a man covenants that it shall rain to…morrow； or that A shall paint a picture； he only says； in a short form； I will pay if it does not rain； or if A does not paint a picture。 But that is not necessarily so。 A promise could easily be framed which would be broken by the happening of fair weather； or by A not painting。 A promise； then； is simply an accepted assurance that a certain event or state of things shall come to pass。
But if this be true； it has more important bearings than simply to enlarge the definition of the word promise。 It concerns the theory of contract。 The consequences of a binding promise at common law are not affected by the degree of power which the promisor possesses over the promised event。 If the promised event does not come to pass； the plaintiff's property is sold to satisfy the damages； within certain limits； which the promisee has suffered by the failure。 The consequences are the same in kind whether the promise is that it shall rain； or that another man shall paint a picture； or that the promisor will deliver a bale of cotton。
＇300＇ If the legal consequence is the same in all cases； it seems proper that all contracts should be considered from the same legal point of view。 In the case of a binding promise that it shall rain to…morrow； the immediate legal effect of what the promisor does is； that he takes the risk of the event； within certain defined limits； as between himself and the promisee。 He does no more when he promises to deliver a bale of cotton。
If it be proper to state the common…law meaning of promise and contract in this way； it has the advantage of freeing the subject from the superfluous theory that contract is a qualified subjection of one will to another； a kind of limited slavery。 It might be so regarded if the law compelled men to perform their contracts； or if it allowed promisees to exercise such compulsion。 If； when a man promised to labor for another； the law made him do it； his relation to his promisee might be called a servitude ad hoc with some truth。 But that is what the law never does。 It never interferes until a promise has been broken； and therefore cannot possibly be performed according to its tenor。 It is true that in some instances equity does what is called compelling specific performance。 But； in the first place； I am speaking of the common law； and； in the next； this only means that equity compels the performance of certain elements of the total promise which are still capable of performance。 For instance； take a promise to convey land within a certain time； a court of equity is not in the habit of interfering until the time has gone by； so that the promise cannot be performed as made。 But if the conveyance is more important than the time； and the promisee prefers to have it late rather than never； the law may compel the performance of ＇301＇ that。 Not literally compel even in that case； however； but put the promisor in prison unless he will convey。 This remedy is an exceptional one。 The only universal consequence of a legally binding promise is； that the law makes the promisor pay damages if the promised event does not come to pass。 In every case it leaves him free from interference until the time for fulfilment has gone by； and therefore free to break his contract if he chooses。
A more practical advantage in looking at a contract as the taking of a risk is to be found in the light which it throws upon the measure of damages。 If a breach of contract were regarded in the same light as a tort； it would seem that if； in the course of performance of the contract the promisor should be notified of any particular consequence which would result from its not being performed； he should be held liable for that consequence in the event of non…performance。 Such a suggestion has been made。 /1/ But it has not been accepted as the law。 On the contrary； according to the opinion of a very able judge； which seems to be generally followed； notice； even at the time of making the contract； of special circumstances out of which special damages would arise in case of breach； is not sufficient unless the assumption of that risk is to be taken as having fairly entered into the contract。 /2/ If a carrier should undertake to carry the machinery of a saw…mill from Liverpool to Vancouver's Island； and should fail ＇302＇ to do so； he probably would not be held liable for the rate of hire of such machinery during the necessary delay； although he might know that it could not be replaced without sending to England； unless he was fairly understood to accept 〃the contract with the special condition attached to it。〃 /1/
It is true that； when people make contracts； they usually contemplate the performance rather than the breach。 The express language used does not generally go further than to define what will happen if the contract is fulfilled。 A statutory requirement of a memorandum in writing would be satisfied by a written statement of the promise as made； because to require more would be to run counter to the ordinary habits of mankind； as well as because the statement that the effect of a contract is the assumption of the risk of a future event does not mean that there is a second subsidiary promise to assume that risk； but that the assumption follows as a consequence directly enforced by the law； without the promisor's co…operation。 So parol evidence would be admissible； no doubt； to enlarge or diminish the extent of the liability assumed for nonperformance； where it would be inadmissible to affect the scope of the promise。
But these concessions do not affect the view here taken。 As the relation of contractor and contractee is voluntary； the consequences attaching to the relation must be voluntary。 What the event contemplated by the promise is； or in other words what will amount to a breach of contract； is a matter of interpretation and construction。 What consequences of the breach are assumed is more remotely； in like manner； a matter of construction； having regard ＇303＇ to the circumstances under which the contract is made。 Knowledge of what is dependent upon performance is one of those circumstances。 It is not necessarily conclusive； but it may have the effect of enlarging the risk assumed。
The very office of construction is to work out； from what is expressly said and done； what would have been said with regard to events not definitely before the minds of the parties； if those events had been considered。 The price paid in mercantile contracts generally excludes the construction that exceptional risks were intended to be assumed。 The foregoing analysis is believed to show that the result which has been reached by the courts on grounds of practical good sense； falls in with the true theory of contract under the common law。
The discussion of the nature of a promise has led me to analyze contract and the consequences of contract somewhat in advance of their place。 I must say a word more concerning the facts which constitute a promise。 It is laid down； with theoretical truth； that； besides the assurance or offer on the one side； there must be an acceptance on the other。 But I find it hard to think of a case where a simple contract fails to be made； which could not be accounted for on other grounds； generally by the want of relation between assurance or offer and consideration as reciprocal inducements each of the other。 Acceptance of an offer usually follows by mere implication from the furnishing of the consideration； and inasmuch as by our law an accepted offer； or promise； until the consideration is furnished； stands on no different footing from an offer not yet accepted； each being subject to revocation until that time； and each continuing ＇304＇ until then unless it has expired or has been revoked； the question of acceptance is rarely of practical importance。
Assuming that the general nature of consideration and promise is understood； some questions peculiar to bilateral contracts remain to be considered。 These concern the sufficiency of the consideration and the moment when the contract is made。
A promise may be a consideration for a promise； although not every promise for every other。 It may be doubted whether a promise to make a gift of one hundred dollars would be supported by a promise to accept it。 But in a case of mutual promises respectively to transfer and to accept unpaid shares in a railway company； it has been held that a binding contract was made。 Here one party agrees to part with something which may prove valuable； and the other to assume a liability which may prove onerous。 /1/
But now suppose that there is no element of uncertainty except in the