In 2001, three research groups from the field of systematic theology and church history at the Faculty of Theology, K.U.Leuven, decided to join forces in an interdisciplinary project, entitled: Orthodoxy: Process and Product. The main aim of this project consists of a church-historical and systematic-theological study of the determination of truth in church and theology. Senior and junior scholars from the three groups agreed to take this theme as the starting point and leading question from which the many research projects they are engaged in, could be brought into relationship and - as far as possible - integrated. Although the question for theological truth already structured the research being conducted in the three groups to a significant degree, joining forces promised the realisation of a surplus-value, and this both through the gathering of a considerable critical mass (in total more than thirty junior and senior researchers) and the interdisciplinary design of the project. In this volume a first collection of contributions to this project, from a diversity of angles and research subjects, is presented. In these contributions scholars from the participating research groups investigate the implications of the overall research question for their particular line of research and research methodologies, and suggest how from this specific research the overall question may be refined and elements of answering it can be provided.