Concilium is a catholic journal in the widest sense: rooted firmly in the Catholic heritage, open to other Christian tradition and the world’s faiths. Each issue of Concilium focuses on a theme of crucial importance and the widest possible concern for our time. In this issue, leading theologians from all over the world consider whether monotheism, so central to both the Christian and the Jewish faith, is tenable in today’s multi-faith and multi-cultural world. Topics include: ‘The Oneness of God in a Plural World’, ‘Biblical Monotheism between Dispute and Revision’, ‘The Unity of the Revealed Law: the Torah and the Qur'an’, ‘Theism and Tolerance in Hinduism’, ‘The Triune God versus Authoritarianism’ and ‘The One Spirit and Many Gods’.