13. It is a question often moved, whether such covenants oblige, as are extorted from men by fear. As for example, whether if a man for fear of death, hath promised to give a thief an hundred pounds the next day, and not discover him; whether such covenant be obligatory, or not. And though in some cases such covenant may be void, yet it is not therefore void, because extorted by fear. For there appeareth no reason, why that which we do upon fear, should be less firm than that which we do for covetousness. For both the one and the other maketh the action voluntary. And if no covenant should be good, that proceedeth from fear of death, no conditions of peace between enemies, nor any laws, could be of force, which are all consented to from that fear. For who would lose the liberty that nature hath given him, of governing himself by his own will and power, if they feared not death in the retaining of it? What prisoner in war might be trusted to seek his ransom, and ought not rather to be killed, if he were not tied by the grant of his life, to perform his promise? But after the introduction of policy and laws, the case may alter; for if by the law the performance of such a covenant be forbidden, then he that promiseth anything to a thief, not only may, but must refuse to perform it. But if the law forbid not the performance, but leave it to the will of the promiser, then is the performance still lawful: and the covenant of things lawful is obligatory, even towards a thief. [Sidenote: Covenant contrary to former covenant, void.] 14. He that giveth, promiseth or covenanteth to one, and after, giveth, promiseth, or covenanteth the same to another, maketh void the latter act. For it is impossible for a man to transfer that right which he himself hath not; and that right he hath not, which he himself hath before transferred. [Sidenote: An oath defined.] 15. An _oath_ is a clause annexed to a promise, containing a renunciation of God’s mercy by him that promiseth, in case he perform not as far as is lawful and possible for him to do. And this appeareth by the words which make the essence of the oath, _so help me God_. So also was it amongst the heathen. And the form of the Romans was, _Thou Jupiter kill him that breaketh, as I kill this beast_. The intention therefore of an oath being to provoke vengeance upon the _breakers_ of covenant; it is to no purpose to swear by men, be they never so great, because their punishment by divers accidents may be avoided, whether they will, or no, but God’s punishment not. Though it were a custom of many nations, to swear by the life of their princes; yet those princes being ambitious of divine honour, give sufficient testimony, that they believed, nothing ought to be sworn by, but the Deity. [Sidenote: Oath to be administered to every man in his own religion.]