Self-mediation is an ever-increasing feature of contemporary life, where one's identity is frequently represented to oneself though digital technology. Dietrich Bonhoeffer therefore presents us with a radical challenge by maintaining that - from the perspective of Christian theology - there is something deeply negative about beholding representations of oneself. He holds that discipleship means adopting a posture of radical agnosticism toward one's own identity.

Phillips focuses on the interrelation of 'simplicity' and 'reflection' in theological cognition and ethical deliberation, showing a wider significance in contemporary theological anthropology, soteriology and ethics. He stands in tradition of reading Bonhoeffer in the philosophical sources, e.g. Wuestenberg, Janz, Whitson-Floyd, Marsh, Zimmermann, Gregor; to sharpen the ways in which Bonhoeffer's work relates to modern debates in epistemology and ethics generally, and that of Dilthey and hermeneutical phenomenology in particular.