MIRACLES are a mixed blessing: one poor shepherd-girl’s apparition can become an episcopal headache. And thus it has proved in the case of the visions of the Blessed Virgin Mary, as experienced at Medjugorje. Mary began appearing to a select few in the Bosnian town in 1981; and she continues to this day to send missives to the pious.

The Vatican launched an investigation in 2010 to assess their authenticity; but Pope Francis has already indicated that he is not a fan of this unregulated form of supernatural contact.

The phenomenon of Marian apparitions was the subject of Beyond Belief (Radio 4, Monday of last week), and — as one might expect from this most intelligent of strands — avoided the snide, patronising line that, for others, might be irresistible.

The shrines of Lourdes, Fatima, and Knock might provoke derision in some quarters; but you cannot argue with Lourdes’s superlative reception of, and care for, those with disabilities, nor the importance of the emotional well-being which such pilgrimage engenders.

We heard from Dr Michael Moran, a member of a medical panel commissioned to authenticate claims of healing. Although he was circumspect on the direct question whether he has witnessed what he would term a miracle — “I’ve seen enough to be impressed” was as far as he would go — he was eloquent in defence of the low-key transformations that typify the Lourdes experience.

Medjugorje, it seems, is something different. The insistence on direct and continuing contact with our Lady — the visionaries now tour the world, taking their pronouncements with them — makes the situation trickier. It is the global publicity that particularly worries the Vatican; and, if one takes the historical view, then one might blame the Vatican itself for creating such a situation. Were these kinds of visitation kept as expressions of local, traditional piety, they would be of little consequence. The fact that there has developed a formal, centralised apparatus for the authentication of miraculous apparitions raises the stakes.

These tales of bishops trying to appropriate and manipulate the spiritual power of local miracle stories has a long historical heritage. Similarly, the story reported so ably and energetically by Linda Pressly in Assignment (World Service, Thursday of last week) rhymes beautifully with the history of monastic corruption, real and fictional, from the Reformation.

This time, it’s Thailand, and the monasteries are Buddhist. The man who wants to take over as Supreme Patriarch of the Sangha — the leading Buddhist authority in Thailand — has a Mercedes convertible parked outside his monastery. There are accusations of tax evasion and, of course, sex scandals.

Then there is the “monk-buster” lawyer, dripping in bling, and a complicated story about large donations from corrupt organisations. And yet, embedded within this story of lip-smacking sensationalism is the story of another Thai monastic tradition, begun by a female monk, Luang Poh Yaai, which cares for drug addicts and drop-outs. And not a Merc. in sight.