Senior Counsel - van den Berg Arbitration
Mr. Constantine Partasides KC’s Keynote Speech at CEPANI on 4 June 2026, defending transparency in arbitral decision-making, gave the international arbitration community serious pause for thought. His proposition was simple: arbitrator silence is not a virtue and the arbitral process is poorer for it. Using vivid imagery, Mr. Partasides KC argued that an arbitrator acting like the Sphinx who sits at the gates of Thebes – silent, enigmatic, inscrutable, offering no clues to the travellers before her, and instead watching as those who cannot answer her riddle are destroyed – is not aiding the arbitral process but rather undermining it. That due process would demand this is a myth (no pun intended!).
Decision-making is a process, not a moment
Mr. Partasides KC grounded his opening argument in both neuroscience and arbitral experience. The brain, he explained, samples evidence progressively, building towards a threshold at which a decision crystallises. After all, Caesar’s declaration that the “die is cast” when crossing the Rubicon, was not a decision made at that moment but was undoubtedly preceded by deliberation, doubt and debate. Arbitral decision-making is no different. Impressions form early, as is unavoidable, but they are also tested, refined, sometimes reversed as new evidence and submissions emerge. The idea that an award emerges from decision-making that begins only once the record closes is “at best a polite fiction”. This point is sound in its simplicity, and one which, I imagine, most arbitrators would privately agree with.
The principled and practical case for transparency
Mr. Partasides KC argued that the arbitrator’s expression of preliminary views is supported by principle as well as practicality. With an ode to the law of contracts, where silence itself can be misleading and dishonest, he argued that procedural justice in arbitration is the same way: parties are far more likely to accept an adverse outcome if the process was transparent and they had the opportunity to address the views that actually shaped the decision. Failing this, parties are left to construct their own narrative around what they imagined the tribunal was thinking.
Omission should not be mistaken with fairness. An expression of preliminary views during the proceeding does not automatically mean that the arbitrator is reneging on the duty to remain open to persuasion. To the contrary, it provides parties with the opportunity to correct a misunderstanding, challenge an assumption, and persuade the arbitrator to reconsider, while also offering members of the tribunal the opportunity to engage with each other’s views. Bias, as Mr. Partasides KC put it, “thrives in opacity” and “is exposed in light”. It would, of course, be a different matter (and indefensible) if the arbitrator were to indicate that they are beyond persuasion entirely.
Practically speaking, preliminary indications serve as a genuine case management tool allowing counsel to deploy their time on what actually matters. They may also create conditions for commercial resolution before the award is rendered.
What other judicial forums can teach us?
In civil and common law jurisdictions alike, transparency in decision-making is unremarkable in court litigation. This, Mr. Partasides KC argued, is an area where the arbitration community would do well to take note.
English judges routinely intervene during hearings to guide the discussion. Indications such as “I'm not with you on that, counsel”, “Is that really your best point?”, or “I wouldn’t spend too long on that if I were you” are not signs of bias but rather expressions of an ongoing decision-making made visible. In Liteky v. United States, Justice Scalia, then sitting on the US Court of Appeals for the 11th Circuit, held that judicial remarks during proceedings, even critical or sceptical ones, do not establish bias unless they reveal deep-seated favouritism beyond persuasion. In Germany, Section 139 of the Code of Civil Procedure imposes a positive obligation on courts to flag concerns at the earliest possible time. This is not regarded as prejudgment, but a procedural duty of fairness.
The underlying rationale, the “deeper procedural truth”, Mr. Partasides KC suggested, runs deeper than efficiency. Drawing on the philosophy of Jürgen Habermas, he observed that legitimacy does not come merely from participation but from communicative rationality, a process by which reasoning is shared and tested through dialogue. Fairness is not only about being heard; it is about knowing precisely what you need to be heard on.
The challenge risk is real but overstated
Mr. Partasides KC argued that arbitration statistics also do not support the fear of challenges that drives arbitrator reticence. Successful challenges in arbitration are rare and those based on an expression of views during the proceedings are rarer still. By way of example, of close to 1000 ICC arbitrations in 2023, only 46 challenges were recorded, of which just eight were upheld. Almost all of the successful challenges related to absence of independence rather than bias.
He illustrated the applicable standard for bias with two cases. In Rutas de Lima v. Municipality of Metropolitan Lima (PCA Case No. 2023-24), a challenge based on an alleged prejudgment in a procedural order on interim relief was rejected on the basis that the tribunal had framed its view as a prima facie likelihood, not a final finding. By contrast, in LCIA Case No. 132498, a dissenting co-arbitrator expressed views on the merits at the preliminary jurisdictional stage, describing the respondent's counterclaim as “not logical” and “impossible to maintain”. This was regarded as an expression of definitive conclusions rather than tentative impressions and the challenge was upheld. The lesson, according to Mr. Partasides KC, is that preliminary views are permissible; definitive pronouncements are not.
Conclusion
Mr. Partasides KC has made a strong case that arbitrators should not be Sphinxes and their developing views should not be a riddle. The evidence shows there is no good reason for this approach. Whether the arbitration community will take heed remains to be seen.
***
We are happy to share the photos of this wonderful event with you. You can find them here: https://galerie.triptyque.be/cepaniga2026/
