This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
The fact that the original transaction was valid and enforceable at law does not of itself oblige a court of equity to grant reformation in every case in which the written instrument does not conform to the actual oral agreement. Reformation is a very extreme remedy. By its means equity compels a person to perform a promise which he has made, it is true, but which has not been put into such a form as to be enforceable at law. It is a more extreme illustration of the power of equity than rescission itself. Equity, accordingly, has power to withhold such remedy where inequitable results will be reached by granting it, even though the original contract might have been enforceable at law.1 This discretionary power of equity is not the arbitrary discretion of the individual chancellor, but, nevertheless, it is a power, the limits of which can not as yet, at least, be fixed by definite and rigid rules. One who seeks reformation is not bound to restore what he has received under the transaction as a condition precedent to such relief.2 If the application for reformation is an incident to another action, a demand for reformation is not necessary as a condition precedent,3 especially if it is shown that such demand would not have been complied with.4