Answ. Yes, if that oath did only tie you to perform your promise; and were no vow to God, which made him a party by dedicating any thing to him; for then the oath being but subservient to the promise, he that dischargeth you from the promise, dischargeth you also from the oath which bound you honestly to keep it.
Quest. XXXI. Am I bound by a promise when the cause or reason of it proveth a mistake?
Answ. If by the cause you mean only the extrinsical reasons which moved you to it, you may be obliged nevertheless for finding your mistake; only so far as the other was the culpable cause, (as is aforesaid,) he is bound to satisfy you; but if by the cause you mean the formal reason, which constituteth the contract, then the mistake may in some cases nullify it (of which enough before).
Quest. XXXII. What if a following accident make it more to my hurt than could be foreseen?
Answ. In some contracts it is supposed or expressed, that men do undertake to run the hazard; and then they must stand obliged. But in some contracts, it is rationally supposed that the parties intend to be free, if so great an alteration should fall out. But to give instances of both these cases would be too long a work.
Quest. XXXIII. What if something unexpectedly fall out, which maketh it injurious to a third person? I cannot sure be obliged to injure another.
Answ. If the case be the latter mentioned in the foregoing answer, you may be thus free; but if it be the former, (you being supposed to run the hazard, and secure the other party against all others,) then either you were indeed authorized to make this bargain, or not; if not, the third person may secure his right against the other; but if you were, then you must make satisfaction as you can to the third person. Yea, if you made a covenant without authority, you are obliged to save the other harmless, unless he knew your power to be doubtful, and did resolve to run the hazard.
Quest. XXXIV. What if something fall out which maketh the performance to be a sin?
Answ. You must not do it; but you must make the other satisfaction for all the loss which you were the cause of, unless he undertook to stand to the hazard of this also (explicitly or implicitly).
Quest. XXXV. Am I obliged if the other break covenant with me?