Under a rough, monkish cowl, skulking in the frayed margins of the historical record, Mael Dub feels elusive, barely knowable. An Irish rover of the seventh century, he is the subject of best guesses rather than undisputed fact. His very name compounds the murkiness. It means ‘dark disciple’. Malmesbury, on the other hand, has not much that is dark or elusive about it. Take the A429 north from the M4 and you are soon there. A beautiful, spick-and-span market town in Wiltshire, perched on a hill overlooking the river Avon.  Towards the end of a mid-winter day thirty years ago, a horse-borne Roger Scruton, the uncrowned philosopher king of rural England, who lives on a farm nearby, attained a vision of the town that he recorded in On Hunting: