Before I tentatively dropped my ballot paper in the box, I feared that making the jump from being a Labour voter to being a Tory one was going to mess with my head far more than it actually has. I expected disorientation, a sense of not knowing my way about.

But, so far at least, the reverse is true. Indeed, some of the landmarks of this new ideological architecture are so familiar, it feels like something of a homecoming.

Among the most familiar and welcome of these landmarks is the presence of the Christian notion of original sin. Theorists of Conservativism don’t always use this language; they are more likely to speak of a suspicion of human perfectibility. But it amounts to pretty much the same thing. The Left believes itself to be participating in some grand project of human improvement, an ambitious endeavour that points towards a comprehensive moral transformation of society. Conservatives don’t believe in this because they have a much more heightened sense of human fallibility.

I don't miss the nastiness of the Left By Giles Fraser

Original sin has developed a bad reputation. It sounds, to secular ears, like a disparagement of the human — overly associated with the church’s tedious obsession with sex. It is certainly true that St Augustine, the great theorist of original sin, was sex obsessed, and so he saw human brokenness through that particular lens. “God grant me continence – but not yet”, has to be one of the wittier intercessions to have been offered up to the divine by a saint of the church.

But properly understood, original sin was simply a very particular way of speaking about human brokenness, and an understanding that this brokenness was deep in the marrow of human life.

Perhaps the best way of recognising original sin as a kind and generous doctrine is to examine the views of those who opposed it, and in particular those of the British monk Pelagius. Like the liberal Left of today, Pelagius believed in human perfectibility. “Be ye perfect as your heavenly father is perfect” was his big sermon idea. God has given us the moral rules, and he wouldn’t expect from us something we are unable to achieve, so there can be no excuses. Moral improvement is the only way to heaven.

Pelagius hated the permissiveness and moral laxity that original sin made possible. No, he insisted, those who fail must be condemned. In many ways, Pelagius is the patron saint of woke, that unforgiving doctrine of moral excellence that cancels all those who cannot live up to its stringent demands. In a recent piece for UnHerd, Gavin Haynes wrote about how this moral bidding war is corroding communities.

The historian Tom Holland commented: “Purity spirals are what happen when societies saturated in Christian assumptions abandon that most democratic of Christian doctrines: original sin. If perfection on earth is possible, then boo to those who are less than perfect.”

Augustine’s idea of original sin is that human beings are constitutionally incapable of the sort of moral perfectionism asked of them by Pelagius. The Adam and Eve story is a way of introducing the idea that our lives are shot through with moral failure like a stick of seaside rock. This is why Christianity is absolutely not a story about human beings being good and then going off to heaven, but is a story about the need for us to recognise our constitutive brokenness and our need to be fixed of it by nothing less than outside help i.e. God.

I don't miss the nastiness of the Left By Giles Fraser

Even leaving these big theological narratives on one side, it is surely obvious that a political philosophy that recognises human weakness is going to be a good deal nicer a political environment than one that whips people on to ever greater demands of moral stringency and then condemns them for failing to live up to what is expected.

It is this Pelagianism of the Left that makes it so nasty a place to be, with its constant monitoring of micro-aggressions, and denunciations of those whose shade of socialism differs, one from another.

A kinder, gentler politics it is not.

Of course, the Left does have something that, superficially at least, looks a little bit like original sin: being white, being male, being straight. There are things that some of us cannot do anything about, things we were born with, and yet they locate us on a map of oppression as the transgressors. But this isn’t how original sin works, because, on the Christian version, sin is something common to all human beings and is, therefore, the reason for existential solidarity among ourselves, not a source of division.

That’s probably why people on the Right often feel like they are a good deal kinder to each other than people on the Left. The search for total innocence becomes persecutory to those who do not achieve it. The acceptance of fallenness, though, is properly inclusive, a recognition that we are all in the same boat, all stumbling about getting it wrong, all children of Adam helping each other along in the dark.

The thing I never understood about the Right, when I was on the Left, was how this pessimism about human nature could be so much more the compassionate option. Like Pelagius, what I recognised in it was moral laxity, indifference even — a refusal to do anything about the great moral ills of society. What I saw in Conservativism was a metaphorical shrugging of the shoulders as people slept on the streets or queued up at the food bank. But I wasn’t looking carefully enough.

I don't miss the nastiness of the Left By Giles Fraser

For whereas the Left generally prefers to discharge its moral obligation to others through the transformation of society, the Right — sceptical of the grand plan — prefers to discharge it through particular acts of individual kindness and practical generosity. Though not ever believing that such acts will totally change the world, the Right fights back against the darkness nonetheless, little by little and at local level. Without the showy drama of the revolutionary, the Conservative responds on the human scale, organically.

Conservatism, then, is the politics of human imperfection. For years I have been an enthusiastic proponent of human fallenness from the pulpit, but have never recognised the connections of all those sermons on Augustine to the political realm. I will never sit comfortably alongside all those free-market liberals who, since Thatcher, have made us confuse proper Conservatism with an ideological commitment to capitalism. That was a temporary alliance needed to defeat Communism.

Boris’s full throttle defence of global capitalism, meanwhile, in his recent speech at Greenwich — salvation by free trade — represented a form of business-minded utopianism in which genuine conservatives ought to detect the dangerous odour of ideology. Conservatives don’t believe in grand plans, whether capitalism or socialism. They see the world as inherently messed up; our job is to get on and try and make the best of it.