St Symeon the New Theologian is, without question, one of the most original and intriguing writers of medieval Byzantium. Indeed, although still largely unknown in the West, he is surely one of the greatest of all Christian mystical writers; not only for the remarkable autobiographical accounts he gives of several visions of the divine light, but also for the passionate quality of his exquisite Hymns of Divine Love, the remarkable intensity of his pneumatological doctrine, and the corresponding fire he brings to his preaching of reform in the internal and external life of the Church. He was a highly controversial figure in his own day. His disciples venerated him as a saint who had returned to the roots of the Christian tradition and personified its repristinization. His opponents, who secured his deposition and exile, regarded him as a dangerously unbalanced incompetent who, by overstressing the value of personal religious fervour, had endangered the stability of that tradition. The Vita which we possess was composed in 1054, in an attempt to rehabilitate Symeon’s memory and prepare for the return of his relics to the capital from which he had been expelled when alive. This paper will investigate how he himself understood and appropriated aspects of the earlier tradition (particularly monastic spirituality), hoping to elucidate why he felt himself inspired to reformist zeal, and why many of his contemporaries (not simply his ‘worldly opponents’ as his hagiographer would have us believe) regarded him as unbalanced. It will end by attempting some reflection on what the controversy reveals on the larger front about how the Church ‘selectively looks back on itself, so to paraphrase our president’s description of the conference theme, and whether the model of tradition and its reception exemplified in this Byzantine writer can offer anything to the dialogue between history and theology which the doctrine of Tradition (Paradosis) inevitably initiates.