This email correspondence from February 2011 between Ladislav Hejdánek and Tomáš Trusina blends practical concerns with profound philosophical reflection. The exchange begins with a mundane search for a lost mobile phone following a meeting, illustrating the personal bond between the two authors. The core of the document, however, focuses on a discussion regarding the creation and establishment of concepts. Hejdánek responds to Trusina’s inquiry about whether theologians can define concepts on behalf of philosophers. He argues that while anyone can create concepts, their validity depends on internal consistency and long-term logical endurance. Hejdánek distinguishes between theology as a specialized science and theology as a discipline akin to philosophy. Using Søren Kierkegaard as an example, he demonstrates how a theologian can competently introduce new terminology if they master philosophical rigor. He cautions theologians against surrendering their conceptual sovereignty to philosophers, urging them to maintain their own intellectual independence. The text provides significant insight into Hejdánek’s views on the interplay between philosophy, theology, and conceptual creativity.