The final cause of propriety as to moral duties, is of all the most illustrious. To have a just notion of it, the two sorts of moral duties must be kept in view, _viz._ those that respect others, and those that respect ourselves. Fidelity, gratitude, and the forbearing injury, are examples of the first sort; temperance, modesty, firmness of mind, are examples of the other. The former are made duties by means of the moral sense; the latter, by means of the sense of propriety. Here is a final cause of the sense of propriety, that must rouse our attention. It is undoubtedly the interest of every man, to regulate his behaviour suitably to the dignity of his nature, and to the station allotted him by Providence. Such rational conduct contributes in every respect to happiness: it contributes to health and plenty: it gains the esteem of others: and, which is of all the greatest blessing, it gains a justly-founded self-esteem. But in a matter so essential to our well-being, even self-interest is not relied on. The sense of propriety superadds the powerful authority of duty to the motive of interest. The God of nature, in all things essential to our happiness, hath observed one uniform method. To keep us steady in our conduct, he hath fortified us with natural principles and feelings. These prevent many aberrations, which would daily happen were we totally surrendered to so fallible a guide as is human reason. The sense of propriety cannot justly be considered in another light, than as the natural law that regulates our conduct with respect to ourselves; as the sense of justice is the natural law that regulates our conduct with respect to others. I call the sense of propriety a law, because it really is so, not less than the sense of justice. If by law be meant a rule of conduct that we are conscious ought to be obeyed, this definition, which I conceive to be strictly accurate, is applicable undoubtedly to both. The sense of propriety includes this consciousness; for to say an action is proper, is, in other words, to say, that it _ought_ to be performed; and to say it is improper, is, in other words, to say, that it _ought_ to be forborn. It is this very consciousness of _ought_ and _should_ included in the moral sense, that makes justice a law to us. This consciousness of duty, when applied to propriety, is perhaps not so vigorous or strong as when applied to justice: but the difference is in degree only, not in kind: and we ought, without hesitation or reluctance, to submit equally to the government of both.