Here are my tentative suggestions...

(1) "Consideration"
Firstly, because in contract, a mere promise is capable of constituting consideration. In the case of "failure of consideration", what is at issue is failure of the promised counter-performance. The promise alone is not enough (cf. Fibrosa SA v. Fairbairn Lawson). Secondly, because contractual consideration is for value. As Dr. Dannemann pointed out, however, failure of consideration is conceivable in the case of a gratuitous contract. Thirdly because of the extension of the notion of "failure of consideration" to cover failure of basis, a broader and more subjective notion cf. Westdeutsche Landesbank and Guinness Mahon where it is clear that although the counter-performance has been realised (since payment and counter-payment were made at each stage), there is a failure of "consideration" by virtue of the fact that the local authority in each case was not obliged to perform and could have pulled out if it were losing. In other words, the failure of consideration stems from the absence of risk in these speculative contracts. The existence of risk and the prospect of winning is surely the basis of any speculative contract.

In the Lord Archer case, there is no contract, so it may be futile to focus on this distinction. The "failure of consideration" notion of consideration is what is relevant, i.e. the basis for payment. If the judgment is set aside, it fails as a basis and the damages are recoverable.

(2) "Cause"
Contractual "cause" encompasses two separate concepts: the counter-performance or promise thereof and the motivation behind the contract (e.g. in the case of a lease, the former concept corresponds to the enjoyment of the premises in return for paying the rent and the latter refers to the intended use for the premises). "Cause" in the sense of juridical reason is simply the reason for making the payment. So, having entered into the above lease, the lessee will simply pay the rent because of the contract. The prospect of enjoying the premises is only relevant as the "cause" for entering into the contract. Aside from considerations of withholding rent for not being allowed to use the premises, if the rent is paid and the lessee is then not allowed to use the premises, there is no "absence of cause" because the contract constitutes the cause, there is merely a right to sue for damages or terminate for breach of contract. As to restitution on termination, this can be analysed as a case of restitution of "enrichment without cause" since, when the contract is unwound, the cause of the payment of the rent disappears. As such, this reminds us of the judgment that we have been discussing. Whatever may be wrong with the judgment, it is a valid "cause" for the payment until it is set aside.

Matthew Scully
Oxford Institute of Legal Practice.