We should be worried about the survival of parliamentary democracy, our best and possibly only protection against tyranny and arbitrary government. We should be worried that it is being subverted by populism and demagoguery, which flies on wings of emotion and the mass mobilisation of gut reactions, rather than on careful and intelligent argument tested in debate. History teaches that plebiscites are easily manipulated by anti-democratic forces, even though they usually do so in the name of democracy.

Take three examples: the EU referendum, the battle for control of the Labour Party, and the takeover of the US Republican Party by the populist demagogue Donald Trump.