One of the major figures of twentieth-century Catholic theology, Henri Cardinal de Lubac was known for his attention to the doctrine of the church and its life within the contemporary world. In Corpus Mysticum de Lubacinvestigates a particular understanding of the relation of the church to the eucharist. He sets out the nature of the church as communion, a doctrine that influenced the thinking of the Second Vatican Council. With the publication of Corpus Mysticum, this important text of contemporary Catholic ecclesiology and sacramental theology is available for the first time in an English translation. Its publication fills a significant gap in the range of de Lubac's works available to English-speaking scholars. It will be an important resource in the widespread and ongoing ecumenical discussions among Catholic, Protestant, and Orthodox theologians.