In Wagner v. Natl. Fire Ins. Co. (1937), 132 Ohio St. 405, 8 N.E.2d 144, the Supreme Court of Ohio instructed: Mutual mistake is the mistake of all parties to the contract. Reformation is available where it is shown that the written instrument does not express the true agreement entered into between the contracting parties by reason of mistake common to them; in such a case equity affords the restorative remedy of reformation in order to make the writing conform to the real intention of the parties. Equity, however, will never make a new contract for those who executed the writing sought to be reformed. Fidelity & Casualty Co. of New York v. Hartzell Bros. Co. (1924), 109 Ohio St. 566, 2 Ohio Law Abs. 211, 143 N.E. 137. It is established that in a proper case it is admissible to show the true agreement by parol evidence (Davenport v. Widow and Heirs at Law of Sovil, 6 Ohio St. 459); but the law attaches a certain sanctity to written instruments and therefore reformation is available only when the mutual mistake is shown by clear and convincing evidence. (Stewart v. Gordon, 60 Ohio St. 170, 53 N.E. 797). Id. at 412-413.