A contract is an interchange of legal rights, sec 1. Parties must he both hound, sec 2. Terms used must be susceptible of definite construction, sec 3. Concurrence must be as to the same thing, sec 4. Provisional concurrence not to be treated as final, sec 5. Contract may be by conduct, sec 6. Acceptance of services or goods may amount to a contract to pay for them, sec 7. Contracts resolvable into proposal and acceptance, sec 8. Proposal not to bind beyond reasonable time, sec 9. When rejected a proposal is exhausted, sec 9 a. Until accepted a proposal may be revoked, but not afterwards, sec 10. Revocation requires notice brought home to party addressed, sec 11. Except in case of proposer's death or insanity, sec 12. Proposer may bind himself to keep open proposal to specific date, sec 13. Proposal not binding if not continuous, sec 14.

If not accepted within designated limits as to time and place, proposal falls, sec 15.

Proposal and acceptance may be conditional, sec 16.

So of subscriptions to joint enterprises, sec 16a.

Acceptance must be communicated when required, sec 17.

Agreement to be bound on mere posting of acceptance may be implied, sec 18.

Rule depends on terms of proposal, sec 19.

Place of acceptance is place of contract, sec 20.

Time of acceptance is time of contract, sec 21.

Assent must be definite; mere non-refusal is not enough, sec 22.

Grants under seal may bind grantor without communication to grantee, sec 23.

General proposal binds as to all parties taking action in conformity with its terms, sec 24.

So of railway time tables, sec 25.

So of letters of credit and promises to accept bills, sec 25 a.

So of auction sales, sec 25 b. From general proposals are to be distinguished bids for customers, sec 26.

Telegrams may constitute a contract, sec 27. "Voidable" distinguished from' 'void,"

Sec 28.

Sec 1

A contract is an interchange by agreement of legal rights. It must be an interchange, involving the A contract is an inter- assent of two or more persons. It must be by agree-legai ment; a mere intimation of purpose is not sufficient.

It must have legal rights as its object. An agreement between A. and B. to respect each other is not a contract;1 nor is an agreement between A. and B. to commit a 1 Infra, sec 8, 588. Anson on Cont. 14; citing Roll. Ab. 8; Guthing v. Lynn, 2 B. & Ad. 232 ; Taylor p. Brewer, 1 M. & S. 290. In Taylor v. Brewer the agreement was to do services for whatever remuneration should be deemed right. This was held to be a mere engagement of honor.

Chief Justice Marshall (Sturges v. Crowninshield, 4 Wheat. 196) defines a contract as "an agreement in which a party undertakes to do or not to do a particular thing;" Blackstone makes it "an agreement, on sufficient consideration, to do or not to do a particular thing." 2 Black. Com. 446.

In L. 1, sec 2 D. de pact. (2, 14) we have the following: " Et est pactio duorum pluriumve in idem placitum consensus."

The German code (Allg. Landrecht, I. 5, sec 1) defines a contract to be a reciprocal assent to the acquisition or alienation of a right.

In Koch's Forderungen, sec 69, a contract is defined to be a reciprocal express agreement of two or more persons for the establishment or the surrender of a legal relation between them.

Savigny defines a contract (iii. 309) as the union of two or more persons in a common expression of will, by which their legal relations are determined;

" die Vereinigung mehrerer zu einer ubereinstimmenden Willenserklarung, wodurch ihre Rechtsverhaltnisse be-stimmt werden." Hence marriage and adoption are included by him among contracts, in distinction from those older jurists who limited the term to obligatory engagements.

Kant takes a much narrower view, defining a contract to be the united will of two persons for the transfer of property. (Metaphysische Anfangs-grunde der Rechtslehre, pp. 98-103.) Property he defines in the Roman sense, as dominion over a specific thing. Within this definition he comprehends not only contracts of service, but contracts of sale and of exchange. At the same time he regards marriage as a contract, holding that each person in marriage has a lien on the other (ein auf diugliche Art personliches Recht), and that copula carnis is to be regarded as equivalent to tradition. Marriage with him is, therefore, an obligatory contract, which he defines to be "the union of two persons of different sexes for reciprocal sexual possession for life ; die Verbindung zweier Personen verschiedenen Geschlechts zum lebens-wierigen wechselseitigen Besitz ihrer Geschlectseigenschaften."

Hegel, like Kant, apparently treats crime a contract. The agreement, to be a contract, must concern a right whose transfer the law will compel. It must the term contract as limited to transfer of property (Grundlinien der Philosophic des Rechts, sec 71) ; hut this coincidence of opinion is only nominal, as he regards the individual action of a person as a thing, which may be the object of alienation. His view, therefore, is substantially the same as that of Savigny ; though he refuses to regard marriage and treaties as contracts. Savigny coincides with Kant in holding marriage to be a contract, and makes the contract to consist in the reciprocal promises of marital cohabitation and support in general, rejecting Kant's sexual limitation.

Windscheid, who will be constantly quoted in the following pages as one of the most reliable of German commentators, defines (sec 305) a contract as consisting in the union of two declarations of intentions (der Vereinigung zweier Willenserklarungen). The declaration of one party is to the effect that he will be a debtor to the other party, subjecting his will to the will of the other party ; the declaration of the other party is that he accepts this subjection. The one party, in other words, is to perform a certain service; the other to accept this service. It makes no matter, he proceeds to say, which of these declarations ha3 precedence.

Mr. Pollock (3d ed. 1) defines an agreement as "an act in the law whereby two or more persons declare their consent as to any act or thing to be done or performed by some or one of these persons for the use of the others or other of them." " It must be concerned," he adds, "with duties and rights which can be dealt with by a court of justice." It therefore excludes " an appointment between two friends to go out for a walk or to read a book together;" for this is "not meant to produce, nor does it produce, any new legal duty or right, or any change in existing ones." This is covered by the definition in the text that a contract is an interchange by agreement of legal rights. As illustrating an interchange of courtesies that do not amount to an interchange of legal rights, see Potter v. Carpenter, 76 N. Y. 157.

The Indian contract act of 1872 gives the following definitions, following, in the main, Savigny :-

"(a) When one person signifies to another his willingness to do or abstain from doing anything, with a view of obtaining the assent of that other to such act or abstinence, he is said to make a proposal.

(b) When the person to whom the proposal is made signifies his assent thereto, the proposal is said to be accepted. A proposal when accepted becomes a promise.

(c) The person making the proposal is called the 'promisor,' the person accepting the proposal is called the promisee.

(d) When, at the desire of the promisor, the promisee, or any other person, has done or abstained from doing, or does or abstains from doing, or promises to do or abstain from doing something, such act or abstinence or promise is called a consideration for the promise.

(e) Every promise, and every set of promises forming the consideration of each other, is an agreement.

(f) Promises which form the consideration, or part of the consideration for each other, are called reciprocal promises.

(g) An agreement not enforceable by law is said to be void.

Consist, not merely of loose talk, but of a business proposal and acceptance bearing on a specific act.

(h) An agreement enforceable by law is a contract.

(i) An agreement which is enforceable by law at the option of one or more of the parties thereto, but not at the option of the other or others, is a voidable contract.

(j) A contract which ceases to be enforceable by law becomes void when it ceases to be enforceable."

Of the above, the subsections down to (e) may be accepted as giving a succinct and accurate statement of the law. The subsection marked (e) is imperfectly expressed; it would have been better to have said: "Promises made in consideration of each other form an agreement." An agreement is not constituted by a unilateral promise. The distinction taken between void and voidable agreements - the term contract being reserved for agreements which are enforceable at law by one or both parties-is one which will be generally accepted ; and of this Mr. Pollock remarks that it is "a clear improvement, for it makes the legal meaning of the words more precise and convenient, without doing violence to former or even to popular usage." The language of subsections (g) and (j), he adds, "is not exactly applicable to English law," and this observation he extends " in some cases to subsection (i) also." To sustain this he refers to agreements of imperfect obligation which are not enforceable by law, yet are not void. To this it may be added that there are few agreements which are not enforceable by the laws of some country, and that there are few agreements, therefore, which, though not enforceable with us, may not be enforceable somewhere else. To say that void agreements are agreements which can be nowhere enforced would leave us no void agreements to speak of. To say that all agreements not enforceable with us are void would be untrue. On many such agreements parties may be held in other countries. Koch, following the Roman law, divides contracts as follows :-1