Are you avoiding me? A reflection on voidness and voidability

Voidness is an extreme doctrine. Whether a contract or other transaction is or is not void depends upon rules which, although frequently founded in powerful logic or statutory dictat, operate in a rigid way which frequently have little to do with a just or fair outcome between all the persons affected, however hard the law of restitution then seeks to bind up the wounds. By contrast, the equitable principles which regulate the avoidance of a voidable contract by way of rescission are precisely concerned to deliver a just and fair result, particularly to third parties who have acquired rights under the voidable transaction in the meantime. The critical distinction between the two is that the question whether, at strict common law, a contract is or is not void is a mechanical, logical, perhaps philosophical one which has little immediate connection with fairness or proportionality. Restitutionary principles only come into play to clear up the mess once voidness has been recognized or, if in dispute, declared. By contrast, the equitable principles regulating rescission govern whether a merely voidable contract should actually be unwound in the first place, as well as the terms upon which rescission may be ordered. They have fairness and (now) proportionality at their heart.