Natural law reasoning appears most prominently in post-war cases grappling with radically unjust regimes, and in constitutional adjudication concerning fundamental rights. The cases below illustrate courts wrestling with whether and when moral criteria override positive enactment.
The Radbruch Formula cases
Gustav Radbruch, a German legal philosopher and former Justice Minister, converted from positivism after witnessing Nazi atrocities. In a 1946 article, he proposed that statutory law loses validity when the contradiction between positive law and justice reaches an "intolerable" degree, or when a statute consciously denies equality at the heart of justice. German courts subsequently applied this Radbruchsche Formel in prosecutions of former East German officials.
In Border Guard Cases (BGH, 1992; BVerfG, 1996), East German soldiers were prosecuted for killing citizens attempting to cross the Berlin Wall. The soldiers argued they followed standing orders and GDR statutes authorising lethal force. The Federal Court of Justice (Bundesgerichtshof) held that such statutes violated fundamental principles of justice so egregiously that they lacked legal validity (the Federal Constitutional Court later upheld the convictions in 1996). The Court invoked Radbruch: "Statutory law that transgresses the boundary drawn by justice in an unbearable manner cannot claim validity." The soldiers were convicted, though sentences were mitigated. Critics charged retroactive application of Western norms; defenders replied that natural law prohibitions against arbitrary killing transcend regime boundaries.
Riggs v Palmer (1889) 115 NY 506
This American case is frequently cited as common-law natural law reasoning. Elmer Palmer murdered his grandfather to accelerate his inheritance under a valid will. New York's Statute of Wills contained no exception for beneficiaries who murder testators. The majority held Palmer could not inherit, invoking the principle that "no one shall profit by his own fraud, or take advantage of his own wrong." Judge Earl wrote: "All laws, as well as contracts, may be controlled in their operation and effect by general, fundamental maxims of the common law. No one shall be permitted to… take advantage of his own wrong." The dissent (Gray J) protested that the court usurped legislative function and contradicted the statute's plain terms—a positivist objection. The majority's reasoning exemplifies natural law's claim that positive law must be read in light of pre-existing moral principles.
Minister of Home Affairs v Fisher [1980] AC 319 (PC)
Lord Wilberforce, delivering the Privy Council's judgment on the Bermuda Constitution, articulated an interpretive approach resonant with natural law. He described a constitutional Bill of Rights as embodying fundamental values and requiring "generous interpretation avoiding what has been called 'the austerity of tabulated legalism', suitable to give individuals the full measure of the fundamental rights and freedoms referred to." This purposive, rights-maximising methodology reflects the natural law insistence that law serves human goods and dignity. Though formally an exercise in positive constitutional interpretation, the judgment's premise—that fundamental rights exist prior to and inform textual meaning—echoes Finnis's account of law's focal meaning.
Oppenheimer v Cattermole [1976] AC 249 (HL)
The House of Lords confronted a Nazi decree stripping German Jews of citizenship. Lord Cross held the decree was "so grave an infringement of human rights that the courts of this country ought to refuse to recognise it as a law at all." This is strong natural law reasoning: a purported law so unjust that it is denied recognition as law. Lord Salmon concurred, citing "the basic principles of justice and morality which are common to all civilised nations." The decision was controversial—later cases distinguished it narrowly—but it stands as a rare English judicial endorsement of natural law limits on legal validity.
Entick v Carrington (1765) 19 St Tr 1029
Lord Camden's judgment, though predating modern positivism, articulates natural law commitments underlying the common law. Royal officers searched Entick's home under executive warrant (lacking statutory or common-law authority). Camden CJ held the search unlawful: "By the laws of England, every invasion of private property, be it ever so minute, is a trespass… If no excuse can be found or produced, the silence of the books is an authority against the defendant." The reasoning assumes individual rights exist prior to positive enactment and constrain state power—a natural law foundation for the rule of law.
Contemporary resonance
These cases demonstrate that natural law is not merely academic. Courts confronting egregious injustice or constitutional rights adjudication frequently invoke moral principles as interpretive or validity criteria. Positivists respond that such reasoning remains within positive law (constitutional provisions, common law principles incorporated by reference) and does not prove the natural law connection thesis. Natural lawyers retort that the best explanation of these practices acknowledges law's inherent moral dimension.