On 3 June 2026, the Rio Course on Regional and International Dispute Settlement (Rio CRIDS) was honored to welcome Prof. Niels Petersen, Professor of Public Law and International Law at the University of Münster. The course is held by the FGV Jean Monnet Centre of Excellence, co-funded by the European Union under the Erasmus+ programme and directed by Prof. Paula Wojcikiewicz Almeida.

In his lecture, moderated by Prof. Paula Wojcikiewicz Almeida, Prof. Petersen discussed some of the findings from his book, “Equality’s Guardians: How Courts Conceptualize Equality and Non-Discrimination Norms”. He held that, generally, states adopt a limited scope of criteria under which discrimination is prohibited — either general equality norms or non-discrimination norms. However, despite the wording being similar across legislations, there is a large variation in the case law. Prof. Petersen’s research inquired what motivates judges to adopt one or the other doctrine to operationalize equality norms.

The book identified four models of equality adopted by courts: equality as non-discrimination (criteria under which people should not be discriminated against); equality as reasonableness (it does not consider just suspect justifications, but all distinctions); positive equality (the state should impose measures to help vulnerable groups); deferential model (the legislator should determine what is equal and what is not). The authors conducted a systematic analysis of the equality case law of independent courts from 18 jurisdictions to see how they fit into these categories. They concluded that common law countries and most international human rights courts followed the non-discrimination model, while civil law courts tend to be less deferential.

We extend our sincere thanks to Prof. Petersen for sharing his time and expertise with us. We look forward to further collaboration.