I ALWAYS try to do a bit of theo­logy in the summer, and have been look­ing at the writ­ings of Donald Mac­­Kinnon, the philo­sopher and theo­logian who so influenced Rowan Williams in his student years.

MacKinnon was a huge, brood­ing presence in the Divinity Faculty at Cam­­bridge, an Anglo-Catholic lay­man, and a passionate Socialist. For him, the most important dia­logue for Christians to engage with was with Marxism. In the late 1960s and ’70s, Marxism was a global force.

MacKinnon insisted that Chris­tians and Marxists were both enem­ies of any kind of idealism, any escape into timeless truths that could blunt the edge of their mission to cast down the mighty from their seats and exalt the humble and meek. MacKinnon’s most crushing put-down, delivered in a review of an essay by Denis Nine­­ham in the Doctrine Commis­sion’s Christian Believing (1976), was that “Nineham never mentioned Marx.”

MacKinnon suggested, daringly, that Christians could see a parallel be­­tween Lenin’s grasping the mo­­ment to instigate the Bolshevik rev­olu­­tion in 1917, and Christ’s setting his face to go to Jerusalem to con­front the powers that would crucify him. The logic of both move­ments was to risk tragedy for the sake of humanity’s future.

It was heady stuff at the time. No one saw quite how fragile the Soviet system had become until the Berlin Wall came down in 1989, or how Maoist China would embrace cap­ital­­ism while maintaining one-party rule. The world changed, but not in the way that MacKinnon and his followers might have expected.

But the promise of global capital­ism has delivered its goods only patchily. While it can justifi­ably be claimed that free markets have raised billions out of poverty, the cost has been a widen­ing gap be­­tween the power of the global super-rich and the rest — a gap that many believe threatens our demo­cratic institutions.

Reading MacKinnon again has put the fight for the future of the Labour Party into a new perspective. Jeremy Corbyn’s sup­port­­ers believe in the unity of theory and practice. They see the current moment as an oppor­t­­­­unity to be grasped.

This is the time to cast off the Blairite error of seeking peace with capitalism; it is the time to seize on the disillusion­ment of the masses, especially the young. It is a moment for ruthles­sness, for overthrowing the parlia­mentary party, and being prepared (as some already are) to throw bricks through windows and take the struggle to the streets.

The issue is whether the new Left’s attempt to seize the moment by demagoguery could ever deliver a fair and just society, or whether the argu­­ment is just as flawed now as it was then.