His students are teaching all over the world now. That's a legacy that lasts longer than any book.
Their story
Robert Alexy (9 September 1945 - 5 September 2026) was a German jurist and legal philosopher whose three major books reshaped how courts and scholars talk about legal argument, constitutional rights, and the concept of law. Alexander Somek, writing in Die Presse two days after Alexy's death in Kiel, called…
Robert Alexy (9 September 1945 - 5 September 2026) was a German jurist and legal philosopher whose three major books reshaped how courts and scholars talk about legal argument, constitutional rights, and the concept of law. Alexander Somek, writing in Die Presse two days after Alexy's death in Kiel, called him the last international star of legal philosophy. He died at 80, four days before his 81st birthday.
Born in Oldenburg i.O., the son of a senior postal director (Oberpostdirektor), Alexy completed the Abitur and then served three years in the Bundeswehr, finishing as a Leutnant. In the summer semester of 1968 he began studying law and philosophy at the Georg-August-Universität Göttingen, supported by the Studienstiftung des deutschen Volkes. His principal teachers were the philosopher Günther Patzig and the legal philosopher Ralf Dreier. He took the first state law examination in 1973 with the rare grade of 1.0, wrote his dissertation Theorie der juristischen Argumentation (J.D. 1976; book 1978), completed the second state examination in 1978, and remained Dreier's assistant until 1984. The Göttingen Academy's Philologico-Historical Class awarded the dissertation its prize in 1982, an event Alexy later called decisive for staying in scholarship. His 1984 habilitation, Theorie der Grundrechte, secured offers from Regensburg and Kiel; he accepted Kiel in 1986 and later declined chairs at Graz (1991, succession to Ota Weinberger) and Göttingen (1997/98, succession to Dreier).
At Kiel he built what colleagues later called a Kiel or Alexy school of law. Theorie der juristischen Argumentation treated legal discourse as a special case of Jürgen Habermas's general practical discourse and distinguished internal from external justification of legal decisions. Theorie der Grundrechte, inspired by but extending Ronald Dworkin's rules-versus-principles distinction, argued that fundamental rights are principles: Optimierungsgebote, norms that require something to be realized to the greatest extent possible given legal and factual possibilities. From that came the law of balancing and a structural account of proportionality that influenced constitutional adjudication far beyond Germany, including in Latin America and, as Brazilian commentators stressed after his death, the jurisprudence of Brazil's Supremo Tribunal Federal. Begriff und Geltung des Rechts (1992; English The Argument from Injustice) defended a non-positivist concept of law: duly enacted, socially efficacious norms that are not extremely unjust in Radbruch's sense and that belong to a system claiming correctness. Alexy illustrated the claim to correctness with performative contradictions (a constitution calling itself unjust; a judge announcing a knowingly wrong sentence) and debated positivists including Norbert Hoerster and Eugenio Bulygin for decades. Essays such as Mauerschützen applied the Radbruch formula to Berlin Wall shootings and related German reunification cases.
Philosophically he drew on Aristotle, Kant and Frege; among legal theorists, on Kelsen, Hart, Radbruch and Alf Ross. His writings (more than 180 items, translated into 23 languages by the mid-2010s) combined analytical austerity with teaching that filled Kiel's largest lecture halls. He supervised roughly fifty doctorates; pupils include Mattias Kumm, Matthias Klatt, Jan-Reinard Sieckmann, Martin Borowski, Axel Tschentscher, Nils Jansen, Carsten Bäcker, Fernando Leal and Virgílio Afonso da Silva. From 1994 to 1998 he was president of the German section of the IVR; from 2002 an ordinary member of the Göttingen Academy; in 1991 a member of the Joachim-Jungius-Gesellschaft. He received the Order of Merit of the Federal Republic of Germany (Verdienstkreuz 1. Klasse) on 13 April 2010 and the Kiel Science Prize on 30 June 2013. He retired at the end of September 2013, gave a farewell lecture on 17 July 2015 ("Ein Abschied ohne Abschied"), and in 2019 was named Senior Professor heading the Kelsen Forschungsstelle Kiel with Stanley L. Paulson. Somek reported thirty-two honorary doctorates; Kiel's person page lists a long series from Alicante, Buenos Aires, Tucumán, Antwerp, San Marcos and Ricardo Palma in Lima, Prague, Coimbra, many Brazilian and Colombian universities, Puno, Tallinn, Košice and others.
Alexy's private family life beyond his Oldenburg origins was not made public in the sources reviewed for this brief. Cause of death was not disclosed. He died in Kiel on 5 September 2026. Tributes from Vienna, São Paulo, Berlin and Lima stressed the same point: courts and classrooms still argue in the vocabulary he forged.
Biography adapted from German Wikipedia Robert Alexy (preferred biographical base); English Wikipedia Robert Alexy; Alexander Somek, Die Presse, Robert Alexy, der letzte internationale Star der Rechtsphilosophie, ist tot (7.
In their own words
“Principles are optimization requirements.”
Central thesis of Theorie der Grundrechte: principles (Optimierungsgebote) are norms that require something to be realized to the greatest extent possible relative to legal and factual possibilities. Widely cited in secondary literature and Somek's 2026 obituary.
“The greater the degree of non-satisfaction of, or detriment to, one principle, the greater must be the importance of satisfying the other.”
Law of balancing (Abwägungsgesetz), Theorie der Grundrechte (Frankfurt am Main 1994 ed., p. 146 per DE Wikipedia citation).
“X is a sovereign, federal, and unjust republic.”
Alexy's example of a constitution that would be conceptually (performatively) defective because every legal system necessarily claims correctness. Begriff und Geltung des Rechts, 1992, p. 65 per DE Wikipedia.
“The defendant is sentenced to life imprisonment, which is a wrong interpretation of the applicable law.”
Parallel judicial example of a performative contradiction. Begriff und Geltung des Rechts, 1992, p. 68 per DE Wikipedia.
“Die Wissenschaft lebt von Kritik.”
Scholarship lives from criticism. Quoted in CAU Kiel farewell coverage (17 Jul 2015); he had invited a major critic to a conference in his honour.
“Dann sind sie falsch.”
Then they are wrong. Kiel 2015 paraphrase of his anti-positivist conviction that if unjust judgments are still handed down, they are wrong; law necessarily has to do with justice.
“Very good, but can you explain why?”
Teaching catchphrase recalled by Kiel alumni lawyers at BROCK MULLER ZIEGENBEIN in the 2025 Festschrift presentation note: correct but unsubstantiated student answers were pushed toward discourse-theoretic justification.
“Law comprises duly enacted, socially efficacious norms that are not extremely unjust in Radbruch's sense and that belong to a system raising a claim to correctness.”
Compressed final definition of law from Begriff und Geltung des Rechts, 1992, p. 201 per DE Wikipedia.

Exactly. Didn't retreat into ceremony.