Page:Treatise of Human Nature (1888).djvu/540

516  taper, or habit, or grimace, which is suppos'd to resemble them; so lawyers and moralists have run into like inventions for the same reason, and have endeavour'd by those means to satisfy themselves concerning the transference of property by consent. 

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 wou'd not be intelligible, before human conventions had establish'd it; and that even if it were were intelligible, it wou'd 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 tho' 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 facilities of the soul, and see which of them is exerted in our promises.

The act of the mind, exprest by a promise, is not a resolution to perform any thing: 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, declar'd and avow'd. 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 