A Treatise of Human Nature

the imagination in conceiving the transference of property, we take the sensible object, and actually transfer its possession to the person, on whom we would bestow the property. The supposed resemblance of the actions, and the presence of this sensible delivery, deceive the mind, and make it fancy, that it conceives the mysterious transition of the property. And that this explication of the matter is just, appears hence, that men have invented a symbolical delivery, to satisfy the fancy, where the real one is impracticable. Thus the giving the keys of a granary is understood to be the delivery of the corn contained in it: The giving of stone and earth represents the delivery of a manor. This is a kind of superstitious practice in civil laws, and in the laws of nature, resembling the Roman Catholic superstitions in religion. As the Roman Catholics represent the inconceivable mysteries of the Christian religion, and render them more present to the mind, by a taper, or habit, or grimace, which is supposed to resemble them; so lawyers and moralists have run into like inventions for the same reason, and have endeavoured by those means to satisfy themselves concerning the transference of property by consent.

Section V

Of the Obligation of Promises

That the rule of morality, which enjoins the performance of promises, is not natural, will sufficiently appear from these two propositions, which I proceed to prove, viz. that a promise would not be intelligible, before human conventions had established it; and that even if it were intelligible, it would not be attended with any moral obligation.

I say, first, that a promise is not intelligible naturally, nor antecedent to human conventions; and that a man, unacquainted with society, could never enter into any engagements with another, even though they could perceive each other’s thoughts by intuition. If promises be natural and intelligible, there must be some act of the mind attending these words, I promise; and on this act of the mind must the obligation depend. Let us, therefore, run over all the faculties of the soul, and see which of them is exerted in our promises.

The act of the mind, expressed by a promise, is not a resolution to perform anything: For that alone never imposes any obligation. Nor is it a desire of such a performance: For we may bind ourselves without such a desire, or even with an aversion, declared and avowed. Neither is it the willing of that action, which we promise to perform: For a promise always regards some future time, and the will has an influence only on present actions. It follows, therefore, that since the act of the mind, which enters into a promise, and produces its obligation, is neither the resolving, desiring, nor willing any particular performance, it must necessarily be the willing of that obligation, which arises from the promise. Nor is this only a conclusion of philosophy; but is entirely conformable to our common ways of thinking and of expressing ourselves, when we say that we are bound by our own consent, and that the obligation arises from our mere will and pleasure. The only question then is, whether there be not a manifest absurdity in supposing this act of the mind, and such an absurdity as no man could fall into, whose ideas are not confounded with prejudice and the fallacious use of language.

All morality depends upon our sentiments; and when any action, or quality of the mind, pleases us after a certain manner, we say it is virtuous; and when the neglect, or nonperformance of it, displeases us after a like manner, we say that we lie under an obligation to perform it. A change of the obligation supposes a change of the sentiment; and a creation of a new obligation supposes some new sentiment to arise. But it is certain we can naturally no more change our own sentiments, than the motions of the heavens; nor by a single act of our will, that is, by a promise, render any action agreeable or disagreeable, moral or immoral; which, without that act, would have produced contrary impressions, or have been endowed with different qualities. It would be absurd, therefore, to will any new obligation, that is, any new sentiment of pain or pleasure; nor is it possible, that men could naturally fall into so gross an absurdity. A promise, therefore, is naturally something altogether unintelligible, nor is there any act of the mind belonging to it.81

But, secondly, if there was any act of the mind belonging to it, it could not naturally produce any obligation. This appears evidently from the foregoing reasoning. A promise creates a new obligation. A new obligation supposes new sentiments to arise. The will never creates new sentiments. There could not naturally, therefore, arise any obligation from a promise, even supposing the mind could fall into the absurdity of willing that obligation.

The same truth may be proved still more evidently by that reasoning, which proved justice in general to be an artificial virtue. No action can be required of us as our duty, unless there be implanted in human nature some actuating passion or motive, capable of producing the action. This motive cannot be the sense of duty. A sense of duty supposes an antecedent obligation: And where an action is not required by any natural passion, it cannot be required by any natural obligation; since it may be omitted without proving any defect or imperfection in the mind and temper, and consequently without any vice. Now it is evident we have no motive leading us to the performance of promises, distinct from a sense of duty. If we thought, that promises had no moral obligation, we never should feel any inclination to observe them. This is not the case with the natural virtues. Though there was no obligation to relieve the miserable, our humanity would lead us to it; and when we omit that duty, the immorality of