manifested is by an offer and an acceptance of the offer. Two persons are not likely to express at the identical minute the same proposition. It is as a practical matter, then, essential that one should make a proposition, and if a contract is to be made, that the other should assent to it. An offer may be made to one or more specified persons, or to anyone whomsoever who will do what the offer requests, as in case of an offer of a reward. An offer is itself a promise, but is a promise conditional on the payment of a consideration or return for it either by some act or some promise from the other party. According as the offer asks for an act or a promise it will fall into one or the other of the two great divisions of simple contracts; one kind is called unilateral (meaning one-sided), that is, a promise only on one side; the other is bilateral, a promise on each side.

ILLUSTRATIONS.—Let us give illustrations of these contracts. We say to John: "We will promise to give you, John, $100 if you will do a specified piece of work." That is a proposal to make an exchange of the work for the money in a sense, but more exactly it is an offer to exchange an agreement to give the money in return for the work. We are not saying to John: "If you will agree or promise to do that work we will promise to give you the money." We are saying that we will give him the money if he actually does the work. That offer requires the actual doing of the work before it is binding. Until then the price requested for the promise has not been paid. It is an offer of a unilateral contract. Again, when we say to a man: "If you will spade up our garden we will pay you $2 a day," we are making an offer for a unilateral contract. We are asking him to spade up the garden; not to promise to spade it up, but to do it, and when he does it he can hold us liable on our promise to pay him $2 a day. The promise will have become binding because we have been given the payment that we asked for in our promise. But if we say to a man: "If you will agree to work for us the next month we will pay you $100," and the man says, "All right," then we have a bilateral contract. We are asking him, as the price of our promise, not to work but to agree to work, and he has promised to do so. To say "I accept" is always sufficient acceptance in the case of a bilateral contract where a promise is requested, but if I said to you, "I will give you $5 if you will bring me a book here," it would not make a contract to say "I accept." I said I would give you $5 if you brought the book here, and nothing but bringing it here will form a contract. The offeree must always do what the offerer asks him. If an offerer asks for a promise, any form of words indicating assent would be sufficient, because they would mean, in effect: "I consent to make the promise you specify in your offer." The form of wording in simple contracts is immaterial. Any plain language is sufficient for an offer, and as for acceptance, it does not matter whether the acceptor says "all right," or "I accept your offer," or in what form he expresses his assent. The question is, does he express assent? Now, the offerer is at liberty to name any consideration in his offer that he sees fit. He can name, in other words, whatever price for his promise he chooses to ask. If the person addressed does not choose to pay that price, all he has to do is to reject the offer, but he can bind the offerer only on the terms proposed. Therefore, if the offerer asks for an act in return for his promise, that is, asks for an immediate payment, or work, or the giving of property for his promise, no contract can be made by the person addressed saying, "All right, I will do it;" that is not giving the price the offerer asked. On the other hand, should the offerer ask for a promise and not for an act, the acceptor must give the promise asked for.

OPTION WITHOUT CONSIDERATION.—A common business transaction that presents very well the principles governing the formation of simple contracts is what is called an option. Suppose the owner of a mine says: "I will sell you this mine for $50,000, and you may have thirty days to decide whether you choose to accept the offer or not." Now, it does not matter whether that statement is oral or in writing; it is merely an offer, and not binding as the matter stands as far as we have stated. However, if it were in writing and a seal attached (in a State where seals still have the force which the common law gave them) it would be a binding promise to sell the mine at that price at any time within thirty days. If there is no seal attached, as long as the offer is unaccepted and unpaid for, it is not binding. The man who makes it may say: "I withdraw my offer. It is true that I promised to keep the offer open thirty days, but you did not pay me for that promise and I am going to break the promise. I withdraw my offer." Any offer for the formation of a simple contract, while unaccepted, may be withdrawn. But, if before it was withdrawn and within the thirty days' limit, the person to whom the option was given says, "Here is the $50,000 which you said you would take for your mine," the offerer would then be bound, and would have to perform his part of the contract.

OPTION WITH CONSIDERATION.—Let us change the character of the option a little. Suppose in consideration of $1000 paid down the owner of a mine promises to sell the mine for $50,000 at any time within thirty days. Here the offer, or the contract—for it is now more than an offer—has been paid for, and it is therefore binding. The person to whom the offer was made paid $1000 for the promise, therefore the promisor is bound to keep it. It was not an absolute promise to give the mine to the buyer, but it was a promise to sell it to him for $50,000 if he chose to take it within thirty days; that is a conditional promise. A conditional promise may be binding and paid for just as well as an absolute promise.

INSURANCE POLICY.—Take the case of a fire insurance policy. That is a conditional promise, a promise to pay indemnity for the destruction of a house by fire. Therefore, the performance of the insurance company's promise is conditional on the suffering by the insured of loss by fire. An insurance policy is ordinarily a unilateral contract; the premium is the consideration or price paid for the promise, and the promise is binding on the insurance company from the time when the premium is thus paid. Of course, the promise is only binding according to its terms. The insured has bought a conditional promise, a promise to pay if the house burns down. He gets that promise, but he will not become entitled to any money or any damages unless the house burns down nor unless he complies with the other conditions of his policy.

GUARANTEE.—Another kind of a promise worth referring to is a guarantee. A question arises whether a business house will sell something to a buyer on credit, and it decides it will not without a guarantee. Accordingly, John agrees, in writing, that if the business house in question will sell James a bill of goods, John will guarantee the payment of the price. That means, if James does not pay for the goods, John will. That is a unilateral contract in which the promise is conditional, and the consideration for that promise is the selling of goods to James.

PRELIMINARY NEGOTIATIONS—ADVERTISEMENTS.—An offer is sometimes difficult to distinguish from other things. Suppose the case of an advertisement. A business house advertises that it will sell goods for a certain price. Take the case of a bond list issued by a banking house. The list states that the banking house will sell specified kinds of bonds at quoted prices. John receives one of those lists, looks it over, sees something that looks good to him, and