TO THE bored schoolboy, it was one of the passages that made Chaucer bearable. The Pardoner has finished his melodramatic morality tale, and tries to sell his dodgy spiritual wares to the pilgrims. The Host turns on him furiously: “I wolde I hadde thy coillons in myn hond In stide of relikes . . . They shul be shryned in an hogges toord.” What the Pardoner was doing, and why he was so despised, was the subject of last week’s In Our Time: Purgatory (Radio 4, Thursday of last week).

For anyone who has got this far into Reformation year without working out what all the fuss was about, this is a good place to start. Purgatory was, depending on how sadistic your imagination was, a place where vices were corrected or punished on your way to salvation. In some traditions, it had a real location on earth — under Mount Etna, or within the Hanger Lane Gyratory System — and, as theology gave way to expediency, various forms of money-raising schemes were de­­veloped in response.

Lord Bragg is not one who likes to hang around, in purgatory or anywhere else; and he has a tend­ency to take on a hectoring tone with his nervous academic guests who, dry of mouth, are trying to tell a good story, while not making themselves the subject of sniggers at the next faculty sherry party. He gets particularly shirty when it’s a subject he knows something about — and everyone knows how, before Luther nailed his 95 theses to the church door, you could buy your way into heaven. So, when his guests attempted to finesse this Ladybird Book account, he got irritable.

I regularly offer up prayers of thanks for the existence of In Our Time, but one should acknowledge the purgatorial journey that some academics take to achieve glory and those all-important research-impact credits.

In The Inquiry (World Service, Thursday of last week) we heard about the neuroscientists who are studying poverty and its effect on the brain. As any teacher or aid worker will tell you, poverty creates the condi­tions — poor education, poor health — for its self-perpetuation. But, as one of the scientists interviewed admitted, pretty pictures of brain scans are more effective in making this point than pictures of starving children. It is not enough, appar­ently, that poverty is an evil in itself: it must somehow be proven that poverty is bad for the brain, which in a 21st-century materialist culture is like saying it’s bad for the soul.

The evidence? Poverty takes up “cognitive bandwidth”: the poor waste all their brain capacity worry­ing about the price of milk. It hin­ders parents from spending time with children, leading to something called “synaptic pruning”; and it is bad for health, which is bad for brain development. The programme said that it is not poverty itself that is to blame, but the conditions to which poverty leads. But how one disentangles the essence of poverty from its attend­ant conditions is a philosophical challenge of truly aca­demic com­plexity.