Matthew, his son, is the director of the Left-wing think tank the Institute for Public Policy Research, and presumably likes to make a splash with questions of this sort; but he is also the book's central tragedy, and though they pretend this isn't so, the book is so titled, it transpires, for entirely personal reasons. The question was one Matthew was driven to ask as a child, in the face of his father's indifference to him. It has rather a different ring to it in the light of that information.