| 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 coued 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. |
| [Footnote 21 Were morality discoverable by reason, and not by sentiment, it would be still more evident, that promises cou'd make no alteration upon it. |
| Morality is suppos'd to consist in relation. |
| Every new imposition of morality, therefore, must arise from some new relation of objects; and consequently the will coud not produce immediately any change in morals, but cou'd have that effect only by producing a change upon the objects. |
| But as the moral obligation of a promise is the pure effect of the will, without the least change in any part of the universe; it follows, that promises have no natural obligation. |
| Shou'd it be said, that this act of the will being in effect a new object, produces new relations and new duties; I wou'd answer, that this is a pure sophism, which may be detected by a very moderate share of accuracy and exactness. |
| To will a new obligation, is to will a new relation of objects; and therefore, if this new relation of objects were form'd by the volition itself, we should in effect will the volition; which is plainly absurd and impossible. |
| The will has here no object to which it cou'd tend; but must return upon itself in infinitum. |
| The new obligation depends upon new relations. |
| The new relations depend upon a new volition. |
| The new volition has for object a new obligation, and consequently new relations, and consequently a new volition; which volition again has in view a new obligation, relation and volition, without any termination. |
| It is impossible, therefore, we cou'd ever will a new obligation; and consequently it is impossible the will cou'd ever accompany a promise, or produce a new obligation of morality.] |
| 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. |