Franz Overbeck's radical critique of Christianity and its theology represents a unique contribution to the debate between Christian faith and modernity. In this study attention is focused particularly on the difficulties that spring from Overbeck's commitment to critical rationality on the one hand, and his Romantic sense of religion on the other. This combination, it is argued, together with his sensitivity to the unconditional element in Christianity, may help account for the unresolved complexity and ambivalence of his own relationship to the Christian tradition. Indeed his own writings, it is suggested, contain a persuasively and consistently elaborated secularized version of characteristically Christian motifs. The seriousness of Overbeck's challenge to Christian theology resides in the power of his alternative interpretation of a tradition that he knew so thoroughly and that influenced him so deeply. «All theology needs the troubling light which Overbeck's analysis still casts, better perhaps than any other great modern critique of theology as a discipline» (David Tracy).