Last night Christians on the Left hosted its annual Tawney Dialogue in memory of the Christian socialist and historian RH Tawney.

The guest speakers were shadow chancellor John McDonnell and Prof Daniel Finn, who teaches theology and economics at St John's School of Theology in Collegeville, Minnesota.

In his address, McDonnell said: "At their heart, people are fundamentally altruistic... they don't just want it better for themselves, but they want it for everyone else as well." 

Finn opened the dialogue with an analogy from Catholic Social Teaching that recurred throughout the evening. He said the economy, rather than being a machine, is a symphony. Each part only makes sense with reference to the whole and when one part goes wrong the whole orchestra suffers.

He linked this to another idea in Catholic social theory, that occupations on which capitalism places little value, such as cleaning or cooking, are in fact of immense worth because they are socially useful. He quoted Pope Francis, who once said that business should be judged by whether it performed "useful work".

Furthermore, Christian economics asks, how would the louder parts of the 'symphony', like our banks and skyscrapers, function without the cleaners and cooks who keep it going? Christians talk a lot about 'the common good", and this came up in the questions afterwards. Finn defined this elusive term as both the "common conditions of social life", and the "achievement of the good life by everyone". No one, he said, is excluded.

John McDonnell brought the discussion back down to the practical reality of British politics. In a moment of nostalgia, he lamented the England of his childhood, referring to the hope of the 1960s generation that built Britain's welfare state out of the brokenness of the war. On a number of occasions he repeated the question, "How on earth did we get to where we are now?"

But McDonnell's rallying cry was resolutely socialist: we must rebuild what we have lost, he argued. He told stories of suffering from his own constituency, Hayes and Harlington. An elderly woman, who has lived in council housing for years, was wrongly accused of benefit fraud; teenagers sleep rough on park benches and young workers are on zero hours contracts.

McDonnell argued that what is morally right can be matched to what is most effective, and the result is Daniel Finn's 'common good' symphony. The recent Panama tax scandal showed thiis, he said: "If people just paid their taxes, then we wouldn't need the deficit."

The event finished with questions from the floor. Issue after issue was highlighted, from education cuts to taxes on sanitary products. However, as one questioner suggested, if Labour is the solution to these problems, the biggest issue is that it is not in power. McDonnell avoided a debate about electability and the next election.

The event also generated the hashtag #patriotspaytax. 

Enjoyed following @ChrLeft's #Tawney16 on Twitter this evening. Love the headline: #PatriotsPayTax!

— Steve Holmes (@SteveRHolmes) April 13, 2016

Christians on the Left director Andy Flannagan closed the event. Jonathan Reynolds MP, who shared his remarkable testimony at the AGM, has taken over from Stephen Timms MP as Chair, and other new members were also elected last night.

The organisation will be fielding candidates for forthcoming local elections, campaigning in the EU referendum, and preparing for the election in 2020.

For more about Christians on the Left, visit their website.