I heard Terry Waite last week - just a snippet of a radio trail in which he said that the sort of torture he suffered had a strange, refining effect on his faith. The niceties of detail and dogma disappear: the core remains and is strengthened. That core is, and must always be, love. Peter Roberts's tremendous play picks up this theme. David Calder, the RSC's current, urbane Shylock, plays a troubadour - 'poet, singer, warrior, lover: arrogant second- rate versifier, basically' - who becomes involved with Simon de Montfort's crusade against the Cathars. He falls for a Cathar girl though he loathes her belief; he saves her from stoning and almost accompanies her to the stake.
In old age, he looks back at his dilemma. He could not bring himself to perish for such a creed, though he could almost have wished to die with his beloved. The paradox pivots on the sad irony that he finds more love among the threatened community of life-hating Cathars than in the rigidity of the pre-Reformation Church. This was a play full of unexpected twists and wry comment, subtle as the Inquisition, idealistic as Francis of Assisi, whose new order offered a glimmer of hope that generosity might prevail. The great issues of the 13th century are not as remote as you might think.
A troubadour with nothing of the second-rate about him underlined that idea. I had thought that nobody could follow Seamus Heaney, but the new Oxford Professor of Poetry bowled me over. James Fenton read from his collection Out of Danger for Stanza on Stage (R4). In 'The Ballad of the Imam and the Shah' he speaks of the cumulative effect of transgression and retribution, when one murder leads a whole nation to slaughter, taking the people 'from litany to heresy to fire . . . from villainy to tyranny to war'. Of course, says the poet, the story of internecine savagery and bloodshed he narrates occurred many centuries ago, 'the kind of thing that couldn't happen now'. Of course.
Fenton's metrical, magical lines resonate. Though rigorous in his scorn of cruelty and hypocrisy, he is not ultimately cynical, and some of his apparently simple lyrics make you gasp at their tenderness. Echoes of Eliot and MacNeice sound a ground-bass to his rhythms, as he plays with words like a baby with bath water, splashing them around, marvelling at their translucence, and they fall and settle into tranquil beauty. His reading is fast and thrilling: his is a marvellous radio voice.
The scourge of the Middle Ages was the subject of Omnibus (World Service) this week. Half the population of Europe died of the Black Death in the 14th century and people are still dying of it today. (The Independent's) Richard Dowden described a visit to Zaire where rats rustle in crowded villages and bubonic plague kills stealthily. Chillingly, the bacillus has been bred for military use and survives under guard at Porton Down. Even in hygienic America it can attack without warning, as was described by a vet in the Rockies who had caught it from a wild cat and survived after 10 days in coma, thanks to tetracycline. This was the World Service offering a service to the world: keep your antibiotics handy.
Or escape to Portugal with Radio 3, which has more foreign holidays than most of us have barbecues. Their latest jaunt included an instructive interview with Dom Duarte, Duke of Braganza, who describes himself as hare of the throne, despite the fact that his kingdom is a republic and a new European Community member. In Once and Future Portugal he talked about his ancestor Dom Sebastiao, a boy-king of 'considerably asymmetrical' build who led a hopeless army into North Africa to regain it for Christ, and who disappeared in a desert war one blazing August day in 1578. Mottled marble elephants in a Lisbon monastery support his tomb, but many people believe that he did not die and that, like King Arthur, he will return when his country most needs him. Perhaps everybody needs a legend like that. It was extraordinary to hear the passion and lucidity with which Portuguese intellectuals discussed it. Dom Duarte for one is sure it's true.
Finally to the art critic Brian Sewell, the most entertaining castaway to choose his Desert Island Discs (R4) for weeks. The only child of a widow, he was kept away from school until he was 11, which made him into a self-confessed queer fish. Sue Lawley tried to give him a hard time for his unreconstructed stand against modern art, asking him was he determined to insult and upset whenever he could, but he side- stepped her attack with aplomb: 'I tell an uncomfortable truth from time to time.' Strong women dominated his choice of music - Flagstad belting out the 'Liebestod', Callas with, as he said, a mouthful of razor- blades - but when asked if he could sing he was emphatic: 'What, with this voice? It's bad enough speaking with it.'
It was a fair bet that his luxury would be imaginative, and so it was. He's taking the Michelangelo Pieta from the Vatican. (He hopes to contemplate it on a nice warm island full of coconuts and breadfruit.) If Damien Hirst's pickled sheep strays into the back of his memory, the Pieta will remind him of what a miracle was once hewn out of a block of marble by a very young man, a very long time ago.Reuse content