Arguably, the centrepiece of the Kilkenny Arts Festival is the Hubert Butler Lecture. In memory of the great essayist, his native city hosts a prestigious guest every year to speak on a topic of their choice.  In 2016, the lecture was given by the English philosopher John Gray. In the evocative setting of St Canice’s Cathedral in the heart of the medieval city, the renowned thinker was introduced warmly by the broadcaster Olivia O’Leary.  From memory, she summarised his work and suggested that the timing of his lecture – “The Fragility of Freedom” – was especially apt in the centenary…