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First ECTPIL and TRICI-Law Conference 24–25 May 2019, University of Groningen

The Theory and Philosophy of Customary International Law and its Interpretation

Friday 24 May 2019

09.00 - 09.30


09.30 - 10.15

Academy Building

Opening of the Conference

Marcel Brus (local host)
Pauline Westerman (local host)
Panos Merkouris (local host/co-organiser)
Jörg Kammerhofer (co-organiser, chair ESIL IGILTP)

10.15 - 11.00

Academy Building

Keynote Speech

Chair: Marcel Brus
Keynote Speaker: ICC Judge Pangalangan

11.00 - 11.30

Coffee Break

11.30 - 13.00

Academy Building

The Theory and Philosophy of CIL as a Source of Law

Chair: André de Hoogh
JÓ§rg Kammerhofer : The Theory of Customary International Law after the ILC Project: Between Pragmatism and Disenchantment
Jean d’Aspremont : The Four Lives of Customary International Law
Diego Mejia-Lemos : Customary International Law and the Regulation of the Sources of International Law
Romel Bagares: Enkapsis and the Development of Customary International Law: A Dooyeweerdian Approach

13.00 - 14.15

Academy Building


14.15 - 15.45


Ontological Critiques of CIL (parallel)

Chair: Pauline Westerman
Noora Arajärvi : Misinterpreting Customary International Law: Corrupt Pedigree or Self-fulfilling Prophecy?
Francesca Iurlaro : The Fiction of Customary International Law: an Historical and Theoretical Perspective
Jorge Luis Fabra Zamora : A Hartian Theory of International Customary Law
Timothy William Waters : Tools to Match Desire: Customary International Law’s Plastic Hypocrisy
Andreas Hadjigeorgiou : Beyond Formalism: Reviving the Legacy of Sir Henry Maine for Customary International Law

14.15 - 15.45

Old Courtroom

Faultlines and Weak Spots in the Edifice of CIL (parallel)

Chair: Daniel Peat
Andreas Føllesdal : Whence the Legitimate Authority of Customary International Law: to Honor State Consent, or Legitimate Expectations – or Both?
Max Henry Mayer : Law and its Other: The Making of Customary International Law
Asif Hameed : Particular vs General Rules: A Major Faultline for Customary International Law
Sean Yau : Between Identifying and Conceptualising ‘Exceptions’ to Customary International Law

15.45 - 16.15 Coffee Break

16.15 - 17.45


Alternative Approaches to CIL (parallel)

Chair: Ingo Venzke
David Howard : An Alternative Theory of Customary International Law
Anna Baka : The Phenomenology of Absence in Customary International Law
Frederick Cowel : Can Customary International Law Emerge from Universal Periodic Review Recommendations? A Democratic-Constructivist Theory
Markus Beham : State Interest and Customary International Law – Identifying Custom Through International Relations

16.15 - 17.45

Old Courtroom

Actor Variety in the Content-Determination of CIL (parallel)

Chair: Brigit Toebes
Catherine Brölmann : Is the Classical Paradigm of State Practice and Opinio Juris still valid today?
Machiko Kanetake : The Determination of Customary International Law by Domestic Courts
Maiko Meguro : Behind the Fiction of Opinio Juris: the Actors that Actually Create International Law
Zhuo Liang : Approaches and Consequences of Incorporating Non-State Armed Groups’ Practice into the Formation of Customary International Humanitarian Law

18.30 - 19.30


Welcome Drinks

19.30 - 22.00



Saturday 25 May 2019

09.00 - 10.45

Old Courtroom

Domestic Courts Lessons on the Theory and Interpretation of CIL (parallel)

Chair: Geir Ulfstein
Cedric Ryngaert : From Customary Law Ascertainment to Interpretation: the Role of Domestic Courts
Luigi Crema : Once You Get to the Top of a Positivized Legal System, Customary Law Comes Out Again
Gerard Hoogers : Customary International Law as a Tool for Federal Dispute Settlement
Nina Mileva : Old, New, Borrowed, or Blue: How can we Learn from the Interpretive Practices of Domestic Courts?

09.00 - 10.45

Van Swinderen Huys

The Relevance of Hermeneutics and Interpretation in CIL (parallel)

Chair: Noora Arajärvi
Hugh Thirlway : A Hermeneutic Approach to Customary International Law
Panos Merkouris : The Viability of and Need for Interpretation of Customary International Law
John R Morss : The Interpretation of Customary International Law: Some Questions
Orfeas Chasapis Tassinis : Interpreting State Practice and Interpreting the Rules of Customary International Law: Practical Relevance and Theoretical Reflection

10.45 - 11.15 Coffee Break

11.15 - 13.00

Old Courtroom

Delineating the Interpretative Stage in the ‘Life-Cycle’ of CIL (parallel)

Chair: Malgosia Fitzmaurice
Riccardo di Marco : Customary International Law: Identification vs Interpretation
Mariana Clare de Andrade : Identification, Interpretation and Application of Customary International Law
Kostiantyn Gorobets : Practical Reasoning and Interpretation of Customary International Law
Marina Fortuna : Real Life Examples of Identification and Interpretation of CIL

11.15 - 13.00

Van Swinderen Huys

The Need for Methodological Rigour in the Identification, Interpretation and Application of CIL (parallel)

Chair: Jörg Kammerhofer
Anastasios Gourgourinis : Navigating the Formation, Interpretation and Application of Customary International Law
Vladyslav Lanovoy : The Role of International Courts and Tribunals in the Treatment of Customary International Law: A Plea for Greater Methodological Rigour
Letizia Lo Giacco : Eureka!: On Courts’ Discretion in ‘Ascertaining’ Rules of Customary International Law
Nikolaos Voulgaris : The Genesis of Customary International Law through the International Law Commission; Disentangling Lex Ferenda from Lex Lata

13.10 - 13.30

Van Swinderen Huys


Panos Merkouris (local host/co-organiser)
Noora Arajärvi (co-organiser, chair ESIL IGILTP)

Last modified:24 April 2019 4.06 p.m.