I meet Bernard-Henri Lévy in a colossally luxurious hotel on a tree-lined avenue just behind the Elysée Palace. The French philosopher is half-reclining on a sofa, with one ankle tucked under his thigh, beneath an ornamental bookcase bearing a bust of Voltaire. He wants to discuss his new play, Last Exit Before Brexit, which will receive its world premiere at Cadogan Hall, London, on 4 June, under the auspices of the Hexagon Society.