Say the ratio out loud before you open Reasoning — recalling it unprompted is exactly what the exam pays for.
Why it matters
Public policy is pleaded constantly and succeeds almost never. This is the one successful instance the course records, and it is therefore the example every essay on the defence needs.
Facts
A Maltese decree awarded perpetual maintenance for an illegitimate daughter.
Held
Enforcement was refused on the ground of public policy.
Reasoning
Step one — state the defence. Enforcement fails if the judgment offends the forum's public policy, or was given in penal or revenue proceedings.
Step two — state how rarely it works. Successful pleas are extremely rare, and this is the example the course gives. Treat rarity as part of the rule, not as an aside.
Step three — identify what made this decree different. It was not the award of maintenance but its character — a perpetual obligation, unknown to the forum's own scheme of remedies.
Step four — keep the doctrine narrow. In conflicts the public-policy control is deliberately narrower than in domestic law. A transaction valid by its lex causae is not to be invalidated unless enforcement would offend a moral, social or economic principle so sacrosanct as to require maintenance at all costs and without exception.
Exam use
It opens: What are the defences to the recognition of a foreign judgment? — as the illustration under public policy, between fraud and natural justice.
Give the whole list in order, because the examiner is marking structure: want of jurisdiction (Sirdar Gurdyal Singh, corrected by Lalji Raja), fraud (Abouloff and Vadala for England, Sankaran Govindan for India, Satya for jurisdictional fraud), public policy (this case), and natural justice (Crawley v. Issacs).
Map them onto s. 13 of the Code, which is the Indian form of the same list: (a) not by a court of competent jurisdiction; (b) not on the merits; (c) founded on an incorrect view of international law or a refusal to recognise Indian law where applicable; (d) proceedings opposed to natural justice; (e) obtained by fraud; (f) sustaining a claim founded on a breach of a law in force in India. Note that s. 13 is a rule of conclusiveness, drafted as exceptions, so the burden lies on the party resisting.
Show the difference between exclusion and non-recognition, which is a fine point worth making: revenue and penal laws are still recognised for other purposes even though they are not enforced, so a contract designed to defraud a foreign revenue will not be enforced here.
It does not decide that maintenance orders are generally unenforceable; the objection was to the perpetual character of the obligation.