A vow is either a simple promise to God, or a promise bound with an oath or imprecation. Some would appropriate the name of a vow to this last sort only, (when men swear they will do this or that,) which indeed is the most formidable sort of vowing; but the true nature of a vow is found also in a simple self-obliging promise. [Sidenote: The use of vows.] The true reason and use of vows is but for the more certain and effectual performance of our duties: not to make new laws, and duties, and religions for us, but to drive on the backward, lingering soul to do its duty, and to break over difficulties and delays: that by strengthening our bonds, and setting the danger before our eyes, we may be excited to escape it. [Sidenote: The obligation of vows.] It is a great question, whether our own vows can add any new obligation to that which before lay upon us from the command of God. Amesius saith, (Cas. Consc. lib. iv. c. 16.) _Non additur proprie in istis nova obligatio, neque augetur in se prior: sed magis agnoscitur et recipitur a nobis: passive in istis æque fuimus antea obligati: sed activa recognitione arctius nobis applicatur a nobismetipsis._ Others commonly speak of an additional obligation; and indeed there is a double obligation added by a vow, to that which God before had laid on us, to the matter of that vow. Premising this distinction between _obligatio imponentis_, a governing obligation, (which is the effect of governing right or authority,) and _obligatio consentientis_, a self-obliging by voluntary consent, (which is the effect of that dominion which a rational free agent hath over his own actions,) I say, 1. He that voweth doth oblige himself, who before was obliged by God only; and that a man hath a power to oblige himself, is discerned by the light of nature, and is the ground of the law of nations, and of human converse: and though this is no divine obligation, yet it is not therefore none at all. 2. But moreover he that voweth doth induce upon himself a new divine obligation, by making himself the subject of it. For example; God hath said, "Honour the Lord with thy substance:" this command obligeth me to obey it whether I vow it or not. The same God hath said, "Pay thy vows to the Most High," Psal. l. 14; and, "When thou vowest a vow to God, defer not to pay it," Eccles. v. 4. This layeth no obligation on me till I vow; but when I have vowed it doth: so that now I am under a double divine obligation, (one to the matter of the duty, and another to keep my vow,) and under a self-obligation of my own vow: whence also a greater penalty will be due if I now offend, than else would have been.