Hans Kung is one of the most celebrated theologians of the present day. His audience, which is strong within his own Roman Catholic Church, is equally solid among Christians of other denominations, among those outside the churches and indeed among those at the frontiers of organised religion.

From the start, he has been a rebel, being Swiss and a lover of personal freedom. Many of his books such as Infallible? and On Being a Christian have rocked the Papal boat.

Now after publishing two magnificent and acclaimed volumes of memoirs, Kung has written a much shorter and more personal book to explain his own beliefs.

If one sets aside all scientific knowledge and learning, all formal theological language and the skilful construction of theories, what remains as the core of faith?

What do we need for our lives? What is indispensable to us? Kung writes of trust in life, joy in life and suffering in life and in so doing gives us a summa of his own faith - and life.