2025 will see the 1700th anniversary of the celebration of the fi rst council of Nicaea, and it will provide an opportunity to take a new look at it due to its undeniable importance for theology and for the history of western thought. This signifi cance is not limited to theology alone. The Nicaean challenge of thinking the newness of the revelation contained in the Gospel meant “not only the application but the transformation of Greek philosophy” (K. Hemmerle). Considering the universal acceptance of the content of Nicaea, this occasion will bear also an ecumenical importance.