3. A vow is as null or not to be kept, when the matter is something that is morally or civilly out of our power to do: as if a servant, or a child, or subject vow to do a thing, which he cannot do lawfully without the consent of his superior: this vow is not simply null, for it is a sinful vow (unless it was conditional). Every rational creature is so far _sui juris_, as that his soul being immediately subject to God, he is capable of obliging himself to God; and so his vow is a real sinful vow, when he is not so far _sui juris_ as to be capable of a lawful vowing, or doing the thing which he voweth. Such a one is bound to endeavour to get his superior's consent, but not without it to perform his vow; no, though the thing in itself be lawful. For God having antecedently bound me to obey my superiors in all lawful things, I cannot disoblige myself by my own vows. Yet here are very great difficulties in this case, which causeth difference among the learnedest, pious casuists. 1. If a governor have beforehand made a law for that which I vow against, it is supposed by many that my vow is not to be kept, (the thing being not against the law of God,) because the first obligation holdeth. 2. Yet some think that magistrates' penal laws binding but _aut ad obedientiam aut ad pœnam_, to obedience or punishment, I am therefore obliged in indifferent things to bear his penalty, and to keep my vow.[76] 3. But if I first make an absolute vow in a thing indifferent, (as to drink no wine, or to wear no silks, &c.) and the magistrate afterwards command it me, some think I am bound to keep my vow; because though I must obey the magistrate in all things lawful, yet my vow hath made this particular thing to be to me unlawful, before the magistrate made it a duty. 4. Though others think that even in this case the general obligation to obey my superiors preventeth my obliging myself to any particular which they may forbid in case I had not vowed it, or against any particular which they may command. 5. Others distinguish of things lawful or indifferent, and say that some of them are such as become accidentally so useful or needful to the common good, the end of government, that it is fit the magistrate make a law for it, and the breaking of that law will be so hurtful, that my vow cannot bind me to it, as being now no indifferent thing; but other indifferent things they say belong not to the magistrate to determine of (as what I shall eat or drink, whether I shall marry or not, what trade I shall be of, how each artificer, tradesman, or professor of arts and sciences shall do the business of his profession, &c.) And here the magistrate they think cannot bind them against their vows, because their power of themselves in such private cases is greater than his power over them in those cases. All these I leave as so many questions unfit for me to resolve in the midst of the contentions of the learned. The great reasons that move on both sides you may easily discern. 1.