PVL3704 ASSIGNMENT 1 –
SEMESTER 1 (2025) – (827757)
DUE 13 MARCH 2025
, PVL3704 ASSIGNMENT 1 – SEMESTER 1
(2025) – (827757) DUE 13 MARCH 2025
QUESTION 1 Discuss (by reference to relevant case law)
the requirement that the enrichment must have been
sine causa
In the law of unjust enrichment, one of the key elements that must be satisfied to establish a claim is
that the enrichment must have been "sine causa", meaning without legal cause or justification. This
principle prevents claims where the defendant had a valid legal reason for receiving the benefit.
Definition and Explanation
The phrase sine causa (Latin for "without cause") implies that enrichment cannot be considered unjust if
there is a lawful basis for it. If a person receives a benefit due to a valid contract, a statutory obligation,
or a lawful entitlement, then the enrichment is justified, and no claim for restitution arises.
Case Law Illustrations
1. Moses v Macferlan (1760) 2 Burr 1005
o This is one of the earliest cases in unjust enrichment. The court held that if money is
obtained without a valid legal reason, the person receiving it is obligated to restore it to
the rightful owner.
o Principle: A person should not be unjustly enriched at another’s expense if there is no
valid reason (sine causa) for the enrichment.
2. Pillans & Rose v Van Mierop & Hopkins (1765) 3 Burr 1663
o In this case, money was transferred on the basis of an agreement, but when the
agreement was found to be unenforceable, restitution was ordered because the
recipient no longer had a valid reason to retain the money.
o Principle: If the legal basis for enrichment ceases to exist, the retention of benefits
becomes unjust.
3. Mutual Life & Citizens' Assurance Co Ltd v Evatt (1968) AC 149
o This case reaffirmed that enrichment is unjust only when it lacks a legal foundation. If a
benefit was given under a valid contract, restitution is not available.
o Principle: The presence of a contractual or statutory duty prevents enrichment from
being classified as unjust.
4. BP Exploration Co (Libya) Ltd v Hunt (No 2) [1979] 1 WLR 783
o This case involved a contract for oil exploration that became void due to external
factors. The court ruled that the enrichment was sine causa since the basis for the
contract failed.
o Principle: When the expected cause of enrichment disappears (such as frustration of
contract), restitution may be required.
5. Fibrosa Spolka Akcyjna v Fairbairn Lawson Combe Barbour Ltd [1943] AC 32
SEMESTER 1 (2025) – (827757)
DUE 13 MARCH 2025
, PVL3704 ASSIGNMENT 1 – SEMESTER 1
(2025) – (827757) DUE 13 MARCH 2025
QUESTION 1 Discuss (by reference to relevant case law)
the requirement that the enrichment must have been
sine causa
In the law of unjust enrichment, one of the key elements that must be satisfied to establish a claim is
that the enrichment must have been "sine causa", meaning without legal cause or justification. This
principle prevents claims where the defendant had a valid legal reason for receiving the benefit.
Definition and Explanation
The phrase sine causa (Latin for "without cause") implies that enrichment cannot be considered unjust if
there is a lawful basis for it. If a person receives a benefit due to a valid contract, a statutory obligation,
or a lawful entitlement, then the enrichment is justified, and no claim for restitution arises.
Case Law Illustrations
1. Moses v Macferlan (1760) 2 Burr 1005
o This is one of the earliest cases in unjust enrichment. The court held that if money is
obtained without a valid legal reason, the person receiving it is obligated to restore it to
the rightful owner.
o Principle: A person should not be unjustly enriched at another’s expense if there is no
valid reason (sine causa) for the enrichment.
2. Pillans & Rose v Van Mierop & Hopkins (1765) 3 Burr 1663
o In this case, money was transferred on the basis of an agreement, but when the
agreement was found to be unenforceable, restitution was ordered because the
recipient no longer had a valid reason to retain the money.
o Principle: If the legal basis for enrichment ceases to exist, the retention of benefits
becomes unjust.
3. Mutual Life & Citizens' Assurance Co Ltd v Evatt (1968) AC 149
o This case reaffirmed that enrichment is unjust only when it lacks a legal foundation. If a
benefit was given under a valid contract, restitution is not available.
o Principle: The presence of a contractual or statutory duty prevents enrichment from
being classified as unjust.
4. BP Exploration Co (Libya) Ltd v Hunt (No 2) [1979] 1 WLR 783
o This case involved a contract for oil exploration that became void due to external
factors. The court ruled that the enrichment was sine causa since the basis for the
contract failed.
o Principle: When the expected cause of enrichment disappears (such as frustration of
contract), restitution may be required.
5. Fibrosa Spolka Akcyjna v Fairbairn Lawson Combe Barbour Ltd [1943] AC 32
