Abstract This volume is one of two special issues collecting articles by invited speakers of the conference ‘Celebrating 90 Years of Gödel’s Incompleteness Theorems’ held in Nürtingen (Germany) in July 2021. The conference was organized by the Carl Friedrich von Weizsäcker Center at the University of Tübingen with support by the ERC-funded project Gödel Enigma: Rediscovering Kurt Gödel through his unpublished works at the University of Helsinki and by the Kurt Gödel Society in Vienna.