Chapter 11


July 14, 2022

We refute the opinion that the obligation to fulfil promises is not enacted by the law of nature.

A bare assertion not binding—A promiser bound to fulfil his engagements, though no right to exact the performance of them, is thereby conveyed to another—What kind of promise gives such right—The promiser should possess the right use of reason—Difference between natural and civil law with respect to minors

Promises made under an error, or extorted by fear, how far binding—Promises valid, if in the power of the promiser to perform them—Promise made upon unlawful considerations, whether binding—Manner of confirming the promises made by others, and the conduct of Ambassadors who exceed their instructions, considered—Owners of ships, how far bound by the acts of the masters of such vessels, and merchants by the acts of their factors—Acceptance requisite to give validity to a promise—Promises sometimes revokable—The power of revoking a promise, explained by distinctions

Burdensome conditions annexed to a promise—Means of confirming invalid promises—Natural obligation arising from engagements made for others.

Part 1: The obligation of promises

Where the first object, that presents itself, is the opinion of Franciscus Connanus, a man of no ordinary learning. He maintains an opinion that the law of nature and of nations does not enforce the fulfilment of those agreements, which do not include an express contract.26 Yet the fulfilment of them is right, in cases, where, even without a promise, the performance would be consonant to virtue and equity. In support of his opinion, he brings not only the sayings of Lawyers, but likewise the following reasons. He says, that the person, who makes, and he who believes, a rash promise,132 are equally to blame.

For the fortunes of all men would be in imminent danger, if they were bound by such promises, which often proceed from motives of vanity rather than from a settled deliberation, and are the result of a light and inconsiderate mind. Lastly, the performance of whatever is any way just in itself, ought to be left to the free will of every one, and not exacted according to the rigid rules of necessity. He says that it is shameful not to fulfil promises; not because it is unjust, but because it argues a levity in making them.

In support of his opinion, he appeals also to the testimony of Tully, who has said, that those promises are not to be kept, which are prejudicial to the person to whom they are made, nor, if they are more detrimental to the giver than beneficial to the receiver. But if the performance of an engagement is begun upon the strength of a promise, but not finished, he does not require a complete fulfilment of the promise, but only some compensation to the party for the disappointment. Agreements, he continues, have no intrinsic force of obligation, but only what they derive from the express contracts, in which they are included, or to which they are annexed, or from the delivery of the thing promised. From whence arise actions, on the one side, and exceptions on the other, and bars to all claims of recovery.

But it is through favour of the laws alone, which give the efficacy of obligation to what is only fair and equitable in itself, that obligatory agreements, such as express covenants and other things of that kind, derive their force.

Now there is no consistency in this opinion, taken in the general sense intended by its author. For in the first place it immediately follows from thence, that there is no force in treaties between kings and different nations, till some part of them be carried into execution, especially in those places, where no certain form of treaties or compacts has been established. But no just reason can be found, why laws, which are a kind of general agreement among a people, and indeed are called so by Aristotle, and Demosthenes, should be able to give the force of obligation to compacts, and why the will of an individual, doing every thing to bind himself, should not have the same power; especially where the civil law creates no impediment to it. Besides, as it has been already said that the property of a thing may be transferred, where a sufficient indication of the will is given. Why may we133 not then convey to another the right to claim a transfer of our property to him, or the fulfilment of our engagements, as we have the same power over our actions, as over our property?

This is an opinion confirmed by the wisdom of all ages. For as it is said by legal authorities, that since nothing is so consonant to natural justice, as for the will of an owner, freely transferring his property to another, to be confirmed, so nothing is more conducive to good faith among men, than a strict adherence to the engagements they have made with each other. Thus a legal decision for the payment of money, where no debt has been incurred, except by the verbal consent of the party promising, is thought conformable to natural justice. Paulus the Lawyer also says, that the law of nature and the law of nations agree in compelling a person, who has received credit, to payment. In this place the word, COMPELLING, signifies a moral obligation. Nor can what Connanus says be admitted, which is, that we are supposed to have credit for a full performance of a promise, where the engagement has been in part fulfilled.

For Paulus in this place is treating of an action where nothing is due; which action is entirely void, if money has been paid, in any way, whether according to the manner expressly stipulated, or any other. For the civil law, in order to discourage frequent causes of litigation, does not interfere with those agreements which are enforced by the law of nature and of nations.

Tully, in the first book of his Offices, assigns such force to the obligation of promises, that he calls fidelity the foundation of justice, which Horace also styles the sister of justice, and the Platonists often call justice, TRUTH, which Apuleius has translated FIDELITY, and Simonides has defined justice to be not only returning what one has received, but also speaking the truth.

There are 3 ways of speaking, respecting things which ARE, or which, it is supposed, WILL be in our power.

Part 2: Ways

  1. where an assurance is given of future intentions, and if the assurance be SINCERE at the time it is given, though it should not be carried into effect, no blame is incurred, as it might afterwards not be found expedient. For the human mind has not only a natural power, but a right to change its purpose. Wherefore if any blame attaches to a change134 of opinion, or purpose, it is not to be imputed to the BARE ACT OF CHANGING, but to the CIRCUMSTANCES, under which it happens, especially when the former resolution was the best.

Part 3:

  1. When future intentions are expressed by outward acts and signs sufficient to indicate a resolution of abiding by present assurances. And these kind of promises may be called imperfect obligations, but conveying to the person to whom they are given no RIGHT to exact them. For it happens in many cases that we may be under an obligation of duty, to the performance of which another has no right to compel us. For in this respect the duty of fidelity to promises, is like the duties of compassion and gratitude. In such kinds of promises therefore the person to whom they are made, has no right, by the law of nature to possess himself of the effects of the promiser, as his own, nor to COMPEL him to the performance of his promise.


  1. where such a determination is confirmed by evident signs of an intention to convey a peculiar right to another, which constitutes the perfect obligation of a promise, and is attended with consequences similar to an alienation of property.

There are 2 kinds of alienation:

  1. Of our property
  2. A certain portion of our liberty

Under those of the former kind we may class the promises of gifts, and under the latter the promises of doing certain actions. On this subject we are supplied with noble arguments from the divine oracles, which inform us, that God himself, who can be limited by no established rules of law, would act contrary to his own nature, if he did not perform his promises. From whence it follows that the obligations to perform promises spring from the nature of that unchangeable justice, which is an attribute of God, and common to all who bear his image, in the use of reason. To the proofs of scripture here referred to, we may add the judgment of Solomon, “My son if thou hast been surety for thy friend, thou hast tied up thy hands to a stranger; thou art ensnared by the words of thy mouth, then art thou taken by the words of thine own mouth.” Hence a promise is called by the Hebrews a bond or chain, and is compared to a vow. Eustathius in his notes on the second book of the Iliad, assigns a similar origin to the word ὑποσχεσεως {hyposcheseôs} or engagement. For he who has received the promise, in some135 measure takes and holds the person, that has made the engagement. A meaning not ill expressed by Ovid in the second book of his Metamorphoses, where the promiser says to him, to whom he had promised, “My word has become yours.”

After knowing this, there remains no difficulty in replying to the arguments of Connanus. For the expressions of the lawyers, respecting BARE PROMISES, refer only to what was introduced by the Roman laws, which have made a FORMAL STIPULATION the undoubted sign of a deliberate mind.

Nor can it be denied that there were similar laws among other nations. For Seneca, speaking of human laws, and promises made without proper solemnities, says, “What law, of any country, we may add, obliges us to the performance of bare promises?” But there may naturally be other signs of a deliberate mind, besides a formal stipulation, or any other similar act which the civil law requires, to afford grounds for a legal remedy. But what is not done with a deliberate mind, we are inclined to believe does not come under the class of perfect obligations; as Theophrastus has observed in his book on laws. Nay, even what is done with a deliberate mind, but not with an intention of conceding our own right to another; though it cannot give any one a natural right of exacting its fulfilment, yet it creates an obligation not only in point of duty, but in point of moral necessity. The next matter to be considered is, what are the requisites to constitute a perfect promise.

V. The use of reason is the first requisite to constitute the obligation of a promise, which ideots, madmen, and infants are consequently incapable of making.

The case of minors is somewhat different.

For although they may not have a sound judgment, yet it is not a permanent defect, nor sufficient of itself to invalidate all their acts. It cannot be certainly defined at what period of life reason commences. But it must be judged of from daily actions, or from the particular customs of each country. Amongst the Hebrews a promise made by a male at the age of thirteen, and by a female at the age of twelve, was valid. In other nations, the civil laws, acting upon just motives, declare certain promises made by wards and minors to be void, not only among the Romans, but among the Greeks also, as it has been observed by Dion Chrysostom in his twenty-fifth oration. To do away the136 effect of improvident promises, some laws introduce actions of recovery, or restitution. But such regulations are peculiar to the civil law, and have no immediate connection with the law of nature and of nations, any farther than that wherever they are established, it is consonant to natural justice that they should be observed. Wherefore if a foreigner enter into an agreement with a citizen or subject of any other country; he will be bound by the laws of that country, to which, during his residence therein, he owes a temporary obedience. But the case is different, where an agreement is made upon the open sea, or in a desert island, or by letters of correspondence. For such contracts are regulated by the law of nature alone, in the same manner as compacts made by sovereigns in their public capacity.