In Part 1, I summarise the cases and introduce the issues.  In Part 2, I examine the question of whether the defendants in the cases were enriched at the claimants’ expense. In Part 3 I examine the causes of action (compulsory discharge of the debt of another; and policy) that were discussed in the cases. In Part 4,  I examine whether the cause of action of mistaken discharge of the debt of another should have been discussed in the cases, and I discuss briefly the old Irish case of Rochfort v Earl of Belvidere (1770) Wall L 45 (pdf), in which Lord Lifford LC cited Moses v Macferlan (1760) 2 Burr 1005, 97 ER 976m, [1760] EngR 713 (19 May 1760) (pdf) with approval, and applied it to find an unjust enrichment in the mistaken discharge of the debt of another. (The House of Lords affirmed, without judgment: (1772) 5 Bro PC 299; 2 ER 691, [1772] EngR 55 (8 May 1772) (pdf)). There is an Irish case; there is always an Irish case; and in the context of Samsoondar and Surrey, the Irish case is Rochfort v Belvidere.

In Part 5, I consider the proper role of voluntariness in discharge claims. In Part 6, I put this issue of voluntariness in a larger context, concluding that a range of related defences (payment "at all events" or "with full knowledge of all of the facts", or in "voluntary submission to an honest claim", or on foot of a misprediction relating to some possible future event) are all merely different ways of effectively saying the same thing, that the claimant voluntarily assumed the risk that the enrichment may be irrecoverable. Occam’s Razor suggests that they all ought to be rationalised on that single, simple, basis. Moreover, it is crucial to understand the limits of this defence. If voluntariness is understood to provide a defence to a claim arising from an intention-based unjust factors, then it does not constitute a defence to causes of action arising for reasons unrelated the claimant's intention, such as those that respond to the circumstances of the defendant, or to some strong policy elsewhere in the law requiring restitution. Finally, in Part 7, I consider the defences of change of position, and of enrichment pursuant to obligation. 

Thanks, and stay safe,

Eoin.