St Thomas Aquinas' antiphon from the Office of Corpus Christi, O sacrum convivium, enjoys popularity and remains part of the Liturgy of the Hours, as do other parts of the Office and Mass he composed for the feast. It offers a survey of Eucharistic theology, evoking past (‘the memory of the Passion’) present (‘the soul filled with grace’) and future (‘pledge of future glory’). It points, too to the Eucharistic flavour of authentic Christian spirituality, always remembering the self-giving of the Saviour ‘for us’, becoming what it has received in the Eucharist, and straining forward towards a goal whose foretaste is ever on our lips. On other occasions Aquinas points to these three dimensions of any sacrament, finding its source in the passion of Christ, its content in the effect achieved in the soul and its aim in the glory of communion with God. a goal whose foretaste is ever on our lips. On other occasions Aquinas points to these three dimensions of any sacrament, finding its source in the passion of Christ, its content in the effect achieved in the soul and its aim in the glory of communion with God.