53. General considerations affecting the grant of relief.

Rectification is an equitable remedy by which the court will modify the terms of a written instrument so as to give effect to the intention of the parties to it1. That intention may be genuinely agreed on by the parties (where there is consensus ad idem), or it may be by estoppel (where it is the intention of only one of them, but the other is estopped from denying that it is his as well)2. It is thus the mistake in the way in which the agreement is expressed in writing that is rectified, and not a mistake in the agreement itself3. In the case of a deed poll or volunt