AS ST PAUL’s example makes clear, public renunciation of a position once fiercely held, and wholesale acceptance of the opposite point of view, is an effective evangelistic tool.

But, while I have no doubt that there must be dancing in the streets in certain quarters in response to Trevor Phillips’s Has Political Correct­­ness Gone Mad? (Channel 4, Thursday of last week), this was too discursive and incoherent a documentary to have much impact.

Phillips has reasonable cause to challenge the direction taken by some aspects of the liberal eagerness that he formerly championed to ensure that minorities did not face discrimination: the Student Unions who deny platforms to unpopular, as opposed to incendiary, speakers and the hounding of a distinguished re­­­searcher because of stupid remarks he made at a dinner are worthy objects of scorn.

But spending quite as much of the programme as he did in con­versa­tion with Nigel Farage, or being quite as sympathetic to the blog­­ger imprisoned for tweeting vile threats, is simply spreading the re­­vision too wide to build a clear argument.

His conclusion is that we need to learn to live with a certain level of offence (I see here an opening for Anglican clergy to offer seminars in what that feels like). What he did not consider was con­text: where and how a point is made surely affects the degree of offens­iveness. The key liberal position is that words and attitudes subtly lead to action, and sanction discri­mination and viol­ence. This argu­ment deserves reas­on­­­­­­able scru­tiny, but did not receive it here.

A truly controlled society is on show in SS-GB, BBC1’s Sunday-evening serialisation of Len Deigh­ton’s novel that takes as its starting-point the notion that Hitler won the Battle of Britain, and England is now under Nazi occupa­tion. It is less about Deighton’s re­­writing of history than a detective mystery, with a dis­con­certingly formulaic hero.

Two episodes in, we are begin­ning to grasp the moral com­plex­ities: to what extent has he become a collaborator, a puppet of Hitler’s regime? Or is he building, securely and slowly, resistance to them? The likelihood that everyone is telling lies, and is a double or a triple agent, makes the story almost impossible to follow, but it is done with style and verve.

In contrast to this scenario, the Revd Peter Owen-Jones celebrated the immemorial barrier to invasion presented by the white cliffs in South Downs: England’s mountains green (BBC4, Tuesday of last week). The programme was a gorgeous portrayal of walking the South Downs Way in the course of a year.

This is, he insisted, a man-made environment, in the sense that the carefully managed sheep grazing is what creates the short greensward and its resultant cornucopia of spe­cial­ised flora and fauna. But God must, I think, be accorded some of the praise if he is indeed responsible for the geological forges that created the specific chalk uplands that make possible the clear streams, orchids, butterflies and vineyards.