I do not find this a convincing explanation as to why a misrepresentation entitles the misrepresentee to rescind.

I would be prepared to concede that where there is a common fundamental mistake made by both parties to a contract one plausible explanation as to why the contract is void is that there is an implied condition precedent that the agreement is not to bind.

A agrees to hire B's music hall and surrounding gardens. Unknown to both A and B, ten minutes before the deal was struck the music hall had burnt to the ground.

We might be prepared to say, on an officious bystander test, that there is no contract because it was an implied condition precedent that the music hall existed. We might also be prepared to say that if the music hall burnt down ten minutes after the agreement that there was an implied condition subsequent that the deal was to come to an end.

There are other plausible explanations for the result that the contract is no longer on foot and in the context of frustration the implied condition analysis has become unfashionable.

Where rescission for misrepresentation is concerned, the misrepresentation need not be fundamental nor need it be shared. All that is necessary is that the misrepresentation, however minor, was in part a cause of the decision to enter into the deal (Edgington v Fitmaurice (1885) 29 ChD 459).

A agrees to charter B's ship for six months. Wholly innocently, B misrepresents the size of the propeller. The size of the propeller played a minor role in A's decision to hire the ship.

As the contract is voidable, not void, the implied term would have to be something like:

"If either party misrepresents to the other, regardless of fault, a matter material to the other's entering into the contract, this shall entitle the other party to avoid the deal."

I don't think myself that such an implied term passes the officious bystander test. If we say the term is implied by law, rather than fact, we just get back to asking why the law should imply such a term.

It seems to me that a better explanation is that the misrepresentee's consent has been vitiated by the misrepresentation and that this entitles him to set aside the deal. If I make you a gift because of a misrepresentation you have made to me I am entitled to recover the gift. I do not, myself think that this can be explained through an implied agreement to return the gift. Similarly if I enter into a contract with you because of your holding a gun to my head or because I am hopelessly dependent upon you, I can avoid the deal. I don't think that this is because of any implied agreement that I am entitled to do so.

RS