So far is determined by a plain utility and interest. But perhaps 'tis from more trivial reasons, that _delivery_, or a sensible transference of the object, is commonly required by civil laws, and also by the laws of nature, according to most authors, as a requisite circumstance in the translation of property. The property of an object, when taken for something real, without any reference to morality, or the sentiments of the mind, is a quality perfectly insensible, and even inconceivable; nor can we form any distinct notion, either of its stability or translation. This imperfection of our ideas is less sensibly felt with regard to its stability, as it engages less our attention, and is easily past over by the mind, without any scrupulous examination. But as the translation of property from one person to another is a more remarkable event, the defect of our ideas becomes more sensible on that occasion, and obliges us to turn ourselves on every side in search of some remedy. Now, as nothing more enlivens any idea than a present impression, and a relation betwixt that impression and the idea; 'tis natural for us to seek some false light from this quarter. In order to aid 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_.