His latest book, a six-year 750-page study Philanthropy – from Aristotle to Zuckerberg, has been described by the Wall Street Journal as "a chronicle every bit as encyclopaedic as the title suggests".

[6] Vallely was one of the few correspondents to leave the easy air routes to the feeding camps and strike off across country to find out what was really going on, according to Paddy Coulter, then Head of Media for the aid agency Oxfam.

[7] He uncovered a number of scandals the Marxist government were trying to keep hidden, was pronounced "an enemy of the revolution", arrested by the secret police and expelled from the country.

The book was described by Jonathan Porritt as “required reading for atheistic economists, economically ill-at-ease theologians and any thinking person in between”.

[11] In it Vallely first floated the idea that the biblical concept of Jubilee could be applied to the forgiveness of the debt of developing nations and coined the phrase “from charity to justice” to describe the change that was required in relations between the rich and the poor.

Bob Geldof paid tribute to Vallely's influence in a lecture to the Bar Human Rights Committee Lecture, St. Paul’s Cathedral in which he said: "In his book Bad Samaritans of 1990 Paul Vallely wrote correctly: 'For all his skill as a populist Bob Geldof could not shift the agenda from one of charity to one of justice.” Well maybe after 20 years we’ve finally got there."

In 2004/05 Vallely was co-author of the report of the Commission for Africa set up by the British prime minister, Tony Blair, of which Bob Geldof was a member.

Vallely concluded that Bergoglio did not actively betray two Jesuit priests, Franz Jalics and Orlando Yorio, into the hands of a military death squad, as some critics had alleged.

[20] Thinking Faith,[21] the online journal of the British Jesuits, said it was "a stroke of genius" describing it as "a contemporary biography with the cadences of a film script”.

[21] Reuters[22] said: "Paul Vallely’s Untying the Knots fills the gaps left by ‘instant books’ on Pope Francis".

Vallely's most recent work has been a six-year long study of the history of Western philanthropy, a survey of the subject from the Ancient Greeks and Hebrews to modern times.

The book critiques the excessive utilitarianism of much modern philanthrocapitalism and explores alternative approaches in extended interviews with top philanthropists and leading thinkers – including the late Rabbi Lord Jonathan Sacks; Jonathan Ruffer; Naser Haghamed of the world’s biggest Muslim charity, Islamic Relief; John Studzinski, Archbishop Rowan Williams; Lord David Sainsbury; Bob Geldof; Sir Trevor Pears; Rajiv Shah president of the Rockefeller Foundation; Ian Linden, formerly of the Tony Blair Faith Foundation; Sir Richard Branson; Chris Oecshli of the now spent-out Atlantic Philanthropies; Professor Ngaire Woods, Dean of Oxford’s Blavatnik School of Government; Patrick Gaspard, president of George Soros’s Open Society Foundations; Baroness Eliza Manningham-Buller, chair of the Wellcome Foundation; and Sir Lenny Henry and Kevin Cahill of Comic Relief.

His approach is rooted in Catholic Social Teaching, a rich ethical tradition which draws on 100 years of attempts by the Catholic church to find a third way between unregulated capitalism - and its associated political systems which privilege the individual at the expense of society - and those associated with control by the state which privilege society at the expense of the individual.