Theological reflection upon the Eucharist is dominated by two paradigms: One approach interprets the Eucharist almost exclusively in theological terms, shaped by Scholasticism and the Reformation. Most discussions about the nature of the Eucharist, Eucharistic presence or the role of the priest follow these categories, even if they come in modern disguise. The other reads the Eucharist as an event which can be explored empirically.

O'Loughlin develops a new understanding of the Eucharist. This can be done by looking afresh at the historical evidence and bringing it in dialogue with modern theology. In the past decades, historical research and new discoveries have changed our view of the origins and the development of the Eucharist. By bringing history into a fruitful dialogue with sacramental and liturgical theology, he shows not only ways how theology and practice can be brought closer together again, but also how current ecumenical divisions can be overcome. His book makes an important contribution to eucharistic theology, both for individual church traditions as well as for ecumenical dialogues.