Front Page Titles (by Subject) Chapter 5: Promises - The Principles of Moral and Political Philosophy
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Chapter 5: Promises - William Paley, The Principles of Moral and Political Philosophy 
The Principles of Moral and Political Philosophy, Foreword by D.L. Le Mahieu (Indianapolis: Liberty Fund, 2002).
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I. From whence the obligation to perform promises arises.
II. In what sense promises are to be interpreted.
III. In what cases promises are not binding.
I. From whence the obligation to perform promises arises.
They who argue from innate moral principles, suppose a sense of the obligation of promises to be one of them; but without assuming this, or any thing else, without proof, the obligation to perform promises may be deduced from the necessity of such a conduct to the well-being, or the existence indeed, of human society.
Men act from expectation. Expectation is in most cases determined by the assurances and engagements which we receive from others. If no dependence could be placed upon these assurances, it would be impossible to know what judgement to form of many future events, or how to regulate our conduct with respect to them. Confidence therefore in promises, is essential to the intercourse of human life; because, without it, the greatest part of our conduct would proceed upon chance. But there could be no confidence in promises, if men were not obliged to perform them; the obligation therefore to perform promises, is essential to the same ends, and in the same degree.
Some may imagine, that if this obligation were suspended, a general caution and mutual distrust would ensue, which might do as well: but this is imagined, without considering how, every hour of our lives, we trust to, and depend upon, others; and how impossible it is, to stir a step, or, what is worse, to sit still a moment, without such trust and dependence. I am now writing at my ease, not doubting (or rather never distrusting, and therefore never thinking about it) that the butcher will send in the joint of meat which I ordered; that his servant will bring it; that my cook will dress it; that my footman will serve it up; and that I shall find it upon table at one o’clock. Yet have I nothing for all this, but the promise of the butcher, and the implied promise of his servant and mine. And the same holds of the most important as well as the most familiar occurrences of social life. In the one, the intervention of promises is formal, and is seen and acknowledged; our instance, therefore, is intended to show it in the other, where it is not so distinctly observed.
II. In what sense promises are to be interpreted.
Where the terms of promise admit of more senses than one, the promise is to be performed “in that sense in which the promiser apprehended, at the time, that the promisee received it.”
It is not the sense in which the promiser actually intended it, that always governs the interpretation of an equivocal promise; because, at that rate, you might excite expectations, which you never meant, nor would be obliged to satisfy. Much less is it the sense, in which the promisee actually received the promise; for, according to that rule, you might be drawn into engagements which you never designed to undertake. It must therefore be the sense (for there is no other remaining) in which the promiser believed that the promisee accepted his promise.
This will not differ from the actual intention of the promiser, where the promise is given without collusion or reserve: but we put the rule in the above form, to exclude evasion in cases in which the popular meaning of a phrase, and the strict grammatical signification of the words, differ; or, in general, wherever the promiser attempts to make his escape through some ambiguity in the expressions which he used.
Temures promised the garrison of Sebastia, that, if they would surrender, no blood should be shed. The garrison surrendered: and Temures buried them all alive. Now Temures fulfilled the promise in one sense, and in the sense too in which he intended it at the time; but not in the sense in which the garrison of Sebastia actually received it, nor in the sense in which Temures himself knew that the garrison received it: which last sense, according to our rule, was the sense in which he was in conscience bound to have performed it.
From the account we have given of the obligation of promises, it is evident, that this obligation depends upon the expectations which we knowingly and voluntarily excite. Consequently, any action or conduct towards another, which we are sensible excites expectations in that other, is as much a promise, and creates as strict an obligation, as the most express assurances. Taking, for instance, a kinsman’s child, and educating him for a liberal profession, or in a manner suitable only for the heir of a large fortune, as much obliges us to place him in that profession, or to leave him such a fortune, as if we had given him a promise to do so under our hands and seals. In like manner, a great man, who encourages an indigent retainer; or a minister of state, who distinguishes and caresses at his levee one who is in a situation to be obliged by his patronage; engages, by such behaviour, to provide for him. This is the foundation of tacit promises.
You may either simply declare your present intention, or you may accompany your declaration with an engagement to abide by it, which constitutes a complete promise. In the first case, the duty is satisfied, if you were sincere at the time, that is, if you entertained at the time the intention you expressed, however soon, or for whatever reason, you afterwards change it. In the latter case, you have parted with the liberty of changing. All this is plain: but it must be observed, that most of those forms of speech, which, strictly taken, amount to no more than declarations of present intention, do yet, in the usual way of understanding them, excite the expectation, and therefore carry with them the force of absolute promises. Such as, “I intend you this place”—“I design to leave you this estate”—“I purpose giving you my vote”—“I mean to serve you.” In which, although the “intention,” the “design,” the “purpose,” the “meaning,” be expressed in words of the present time, yet you cannot afterwards recede from them without a breach of good faith. If you choose therefore to make known your present intention, and yet to reserve to yourself the liberty of changing it, you must guard your expressions by an additional clause, as, “I intend at present,” “if I do not alter,” or the like. And after all, as there can be no reason for communicating your intention, but to excite some degree of expectation or other, a wanton change of an intention which is once disclosed, always disappoints somebody; and is always, for that reason, wrong.
There is, in some men, an infirmity with regard to promises, which often betrays them into great distress. From the confusion, or hesitation, or obscurity, with which they express themselves, especially when overawed or taken by surprise, they sometimes encourage expectations, and bring upon themselves demands, which, possibly, they never dreamed of. This is a want, not so much of integrity, as of presence of mind.
III. In what cases promises are not binding.
1. Promises are not binding, where the performance is impossible.
But observe, that the promiser is guilty of a fraud, if he be secretly aware of the impossibility, at the time of making the promise. For, when any one promises a thing, he asserts his belief, at least, of the possibility of performing it; as no one can accept or understand a promise under any other supposition. Instances of this sort are the following: The minister promises a place, which he knows to be engaged, or not at his disposal: A father, in settling marriage-articles, promises to leave his daughter an estate, which he knows to be entailed upon the heir male of his family: A merchant promises a ship, or share of a ship, which he is privately advised is lost at sea: An incumbent promises to resign a living, being previously assured that his resignation will not be accepted by the bishop. The promiser, as in these cases, with knowledge of the impossibility, is justly answerable in an equivalent; but otherwise not.
When the promiser himself occasions the impossibility, it is neither more nor less than a direct breach of the promise; as when a soldier maims, or a servant disables himself, to get rid of his engagements.
2. Promises are not binding, where the performance is unlawful.
There are two cases of this: one, where the unlawfulness is known to the parties, at the time of making the promise; as where an assassin promises his employer to despatch his rival or his enemy; a servant to betray his master; a pimp to procure a mistress; or a friend to give his assistance in a scheme of seduction. The parties in these cases are not obliged to perform what the promise requires, because they were under a prior obligation to the contrary. From which prior obligation what is there to discharge them? Their promise—their own act and deed. But an obligation, from which a man can discharge himself by his own act, is no obligation at all. The guilt therefore of such promises lies in the making, not in the breaking of them; and if, in the interval betwixt the promise and the performance, a man so far recover his reflection, as to repent of his engagements, he ought certainly to break through them.
The other case is, where the unlawfulness did not exist, or was not known, at the time of making the promise; as where a merchant promises his correspondent abroad, to send him a ship-load of corn at a time appointed, and before the time arrive, an embargo is laid upon the exportation of corn—A woman gives a promise of marriage; before the marriage, she discovers that her intended husband is too nearly related to her, or that he has a wife yet living. In all such cases, where the contrary does not appear, it must be presumed that the parties supposed what they promised to be lawful, and that the promise proceeded entirely upon this supposition. The lawfulness therefore becomes a condition of the promise; which condition failing, the obligation ceases. Of the same nature was Herod’s promise to his daughter-in-law, “that he would give her whatever she asked, even to the half of his kingdom.” The promise was not unlawful in the terms in which Herod delivered it; and when it became so by the daughter’s choice, by her demanding “John the Baptist’s head,” Herod was discharged from the obligation of it, for the reason now laid down, as well as for that given in the last paragraph.
This rule, “that promises are void, where the performance is unlawful,” extends also to imperfect obligations: for, the reason of the rule holds of all obligations. Thus, if you promise a man a place, or your vote, and he afterwards render himself unfit to receive either, you are absolved from the obligation of your promise; or, if a better candidate appear, and it be a case in which you are bound by oath, or otherwise, to govern yourself by the qualification, the promise must be broken through.
And here I would recommend, to young persons especially, a caution, from the neglect of which many involve themselves in embarrassment and disgrace; and that is, “never to give a promise, which may interfere in the event with their duty”; for, if it do so interfere, their duty must be discharged, though at the expense of their promise, and not unusually of their good name.
The specific performance of promises is reckoned a perfect obligation. And many casuists have laid down, in opposition to what has been here asserted, that, where a perfect and an imperfect obligation clash, the perfect obligation is to be preferred. For which opinion, however, there seems to be no reason, but what arises from the terms “perfect” and “imperfect,” the impropriety of which has been remarked above. The truth is, of two contradictory obligations, that ought to prevail which is prior in point of time.
It is the performance being unlawful, and not unlawfulness in the subject or motive of the promise, which destroys its validity: therefore a bribe, after the vote is given; the wages of prostitution; the reward of any crime, after the crime is committed; ought, if promised, to be paid. For the sin and mischief, by this supposition, are over; and will be neither more nor less for the performance of the promise.
In like manner, a promise does not lose its obligation merely because it proceeded from an unlawful motive. A certain person, in the life-time of his wife, who was then sick, had paid his addresses, and promised marriage, to another woman; the wife died; and the woman demanded performance of the promise. The man, who, it seems, had changed his mind, either felt or pretended doubts concerning the obligation of such a promise, and referred his case to Bishop Sanderson, the most eminent, in this kind of knowledge, of his time. Bishop Sanderson, after writing a dissertation upon the question, adjudged the promise to be void. In which, however, upon our principles, he was wrong: for, however criminal the affection might be, which induced the promise, the performance, when it was demanded, was lawful; which is the only lawfulness required.
A promise cannot be deemed unlawful, where it produces, when performed, no effect, beyond what would have taken place had the promise never been made. And this is the single case, in which the obligation of a promise will justify a conduct, which, unless it had been promised, would be unjust. A captive may lawfully recover his liberty, by a promise of neutrality; for his conqueror takes nothing by the promise, which he might not have secured by his death or confinement; and neutrality would be innocent in him, although criminal in another. It is manifest, however, that promises which come into the place of coercion, can extend no further than to passive compliances; for coercion itself could compel no more. Upon the same principle, promises of secrecy ought not to be violated, although the public would derive advantage from the discovery. Such promises contain no unlawfulness in them, to destroy their obligation: for, as the information would not have been imparted upon any other condition, the public lose nothing by the promise, which they would have gained without it.
3. Promises are not binding, where they contradict a former promise.
Because the performance is then unlawful; which resolves this case into the last.
4. Promises are not binding before acceptance; that is, before notice given to the promisee; for, where the promise is beneficial, if notice be given, acceptance may be presumed. Until the promise be communicated to the promisee, it is the same only as a resolution in the mind of the promiser, which may be altered at pleasure. For no expectation has been excited, therefore none can be disappointed.
But suppose I declare my intention to a third person, who, without any authority from me, conveys my declaration to the promisee; is that such a notice as will be binding upon me? It certainly is not: for I have not done that which constitutes the essence of a promise—I have not voluntarily excited expectation.
5. Promises are not binding which are released by the promisee.
This is evident: but it may be sometimes doubted who the promisee is. If I give a promise to A, of a place or vote for B; as to a father for his son; to an uncle for his nephew; to a friend of mine, for a relation or friend of his; then A is the promisee, whose consent I must obtain, to be released from the engagement.
If I promise a place or vote to B by A, that is, if A be a messenger to convey the promise, as if I should say, “You may tell B that he shall have this place, or may depend upon my vote”; or if A be employed to introduce B’s request, and I answer in any terms which amount to a compliance with it: then B is the promisee.
Promises to one person, for the benefit of another, are not released by the death of the promisee: for his death neither makes the performance impracticable, nor implies any consent to release the promiser from it.
6. Erroneous promises are not binding in certain cases; as,
1. Where the error proceeds from the mistake or misrepresentation of the promisee.
Because a promise evidently supposes the truth of the account, which the promisee relates in order to obtain it. A beggar solicits your charity, by a story of the most pitiable distress; you promise to relieve him, if he will call again: In the interval you discover his story to be made up of lies; this discovery, no doubt, releases you from your promise. One who wants your service, describes the business or office for which he would engage you; you promise to undertake it; when you come to enter upon it, you find the profits less, the labour more, or some material circumstance different from the account he gave you: In such case, you are not bound by your promise.
2. When the promise is understood by the promisee to proceed upon a certain supposition, or when the promiser apprehended it to be so understood, and that supposition turns out to be false; then the promise is not binding.
This intricate rule will be best explained by an example. A father receives an account from abroad, of the death of his only son; soon after which, he promises his fortune to his nephew. The account turns out to be false. The father, we say, is released from his promise; not merely because he never would have made it, had he known the truth of the case, for that alone will not do; but because the nephew also himself understood the promise to proceed upon the supposition of his cousin’s death: or, at least, his uncle thought he so understood it; and could not think otherwise. The promise proceeded upon this supposition in the promiser’s own apprehension, and as he believed, in the apprehension of both parties; and this belief of his, is the precise circumstance which sets him free. The foundation of the rule is plainly this: a man is bound only to satisfy the expectation which he intended to excite; whatever condition therefore he intended to subject that expectation to, becomes an essential condition of the promise.
Errors, which come not within this description, do not annul the obligation of a promise. I promise a candidate my vote; presently another candidate appears, for whom I certainly would have reserved it, had I been acquainted with his design. Here therefore, as before, my promise proceeded from an error; and I never should have given such a promise, had I been aware of the truth of the case, as it has turned out. But the promisee did not know this; he did not receive the promise, subject to any such condition, or as proceeding from any such supposition; nor did I at the time imagine he so received it. This error, therefore, of mine, must fall upon my own head, and the promise be observed notwithstanding. A father promises a certain fortune with his daughter, supposing himself to be worth so much—his circumstances turn out, upon examination, worse than he was aware of. Here again the promise was erroneous, but, for the reason assigned in the last case, will nevertheless be obligatory.
The case of erroneous promises, is attended with some difficulty: for, to allow every mistake, or change of circumstances, to dissolve the obligation of a promise, would be to allow a latitude, which might evacuate the force of almost all promises: and, on the other hand, to gird the obligation so tight, as to make no allowances for manifest and fundamental errors, would, in many instances, be productive of great hardship and absurdity.
It has long been controverted amongst moralists, whether promises be binding, which are extorted by violence or fear. The obligation of all promises results, we have seen, from the necessity or the use of that confidence which mankind repose in them. The question, therefore, whether these promises are binding, will depend upon this; whether mankind, upon the whole, are benefited by the confidence placed on such promises? A highwayman attacks you—and being disappointed of his booty, threatens or prepares to murder you; you promise, with many solemn asseverations, that if he will spare your life, he shall find a purse of money left for him, at a place appointed; upon the faith of this promise, he forbears from further violence. Now, your life was saved by the confidence reposed in a promise extorted by fear; and the lives of many others may be saved by the same. This is a good consequence. On the other hand, confidence in promises like these, greatly facilitates the perpetration of robberies: they may be made the instruments of almost unlimited extortion. This is a bad consequence: and in the question between the importance of these opposite consequences, resides the doubt concerning the obligations of such promises.
There are other cases which are plainer; as where a magistrate confines a disturber of the public peace in gaol, till he promise to behave better; or a prisoner of war promises, if set at liberty, to return within a certain time. These promises, say moralists, are binding, because the violence or duress is just; but, the truth is, because there is the same use of confidence in these promises, as of confidence in the promises of a person at perfect liberty.
Vows are promises to God. The obligation cannot be made out upon the same principle as that of other promises. The violation of them, nevertheless, implies a want of reverence to the Supreme Being; which is enough to make it sinful.
There appears no command or encouragement in the Christian Scriptures to make vows; much less any authority to break through them when they are made. The few instances* of vows which we read of in the New Testament, were religiously observed.
The rules we have laid down concerning promises, are applicable to vows. Thus Jephtha’s vow, taken in the sense in which that transaction is commonly understood, was not binding; because the performance, in that contingency, became unlawful.
[* ]Acts xviii. 18; xxi. 23.