Baptism has been placed firmly on the agenda of ecumenical theology by the Lima Report, Baptism, Eucharist and Ministry. It makes no attempt to resolve the question of baptismal origins, but judiciously summarizes the state of the debate: ‘While the possibility that infant baptism was practised in the apostolic age cannot be excluded, baptism upon personal profession of faith is the most clearly attested pattern in the New Testament documents’. The paucity of recent discussion of the beginnings of infant baptism may suggest that they are deemed insoluble, short of the discovery of new evidence. Theology, at any rate, may neither be able nor need to wait until historians of primitive Christianity reach a consensus. The possibility that infant baptism was practised relatively early, perhaps even in the New Testament Churches themselves, was no deterrent to Karl Barth's regarding it as theologically indefensible. Nevertheless, he could not ignore what he called ‘the brute fact of a baptismal practice which has become the rule in churches in all countries and in almost all confessions’, and he ventured his own explanation of the triumph of infant baptism and of the New Testament passages to which its advocates customarily appeal. His sharp critique of the tradition provoked a greater stir on the continent of Europe than in the English-speaking world. A fresh look at the historical question is certainly overdue, although its starting-point is bound to be the celebrated exchange between Joachim Jeremias and Kurt Aland of two decades ago. Ecumenical discussion, and in some Churches, ecumenical reality, call on both paedobaptists and credobaptists to examine the others' Practice with a new seriousness. In such a context the beginnings of the dominant tradition cannot healthily be left unscrutinised or treated as inscrutable.