suppose:

money has been received under a judgment which would not have issued had some facts been known

the facts may be so serious as totally to defeat the entire substantive basis for the judgment, or to reduce the substantive measure of recovery

or the unknown facts might constitute procedural errors which leave the substantive basis and measure of recovery untouched

there will be rules as to whether the discovery of particular sorts of error defeats the usual conclusiveness of a judgment

there will be rules as to whether a defeating error can be corrected by setting aside the judgment or by an independent action as with Macferlan described above

where the error correction is effected by the first step of setting aside the judgment, there must be rules as to further proceedings:

1] it could be the rule that, whatever the sort of error, moneys received under the judgment must be repaid, and a proceeding commenced anew toward the substantive judgment to which the original plaintiff is entitled on the facts if any

2] it could be the rule that the original plaintiff would not be required, in the proceeding to set aside the judgment, to yield up everything received and then commence a new proceeding, but could instead, in the set-aside proceeding, establish her substantive rights if any as a set-off or reduction

which ever the procedural structure, it is OBVIOUS that after proceedings are completed in any case in which the judgment is not conclusive, the judgment holder will have that to which she is substantively entitled and will not have that to which she is not substantively entitled

obvious rules tend to be given names--and a name for the rule that a judgment recipient sometimes has to give some of it back--could be called restitution without shocking too many legal minds, and the ground for the restitution might be 'unjust enrichment' again without jarring too many of the profession?

it is however true that the rules as a whole need not be described as containing an element of 'restitution for unjust enrichment' but simply as implementing a system whereby plaintiffs get and keep only that to which they are substantively entitled on the facts of which the system takes cognizance.

american papers have led me to believe that lord archer has been abolished??