First published in 1953 these Hulsean Lectures inquire ''what has been and what should be the attitude of the Church and of individual Christians towards religions other than their own'' and review the policy and methods of Christian missions to non-Christians. Dr Dewick has adopted a definition of ''religion'' sufficiently wide to cover the challenging political-philosophical systems - such as Communism Fascism and Nationalism - which though professedly non-religious or even anti-religious display many of the characteristics of religion; and he shows clearly what principles should underlie the Christian attitude to such pseudo-religions. Dr Dewick spent many years as a missionary in India and Ceylon and writes with particular knowledge of Hindus Muslims and Buddhists. the concluding lectures on ''The Recovery of First Principles'' and ''The Reform of Missionary Policy and Practice'' are particularly interesting.