Karl Popper's The Open Society and Its Enemies explained: piecemeal reform and removable rulers

Karl Popper wrote The Open Society and Its Enemies in New Zealand, where he had gone into exile from Austria, and he wrote it while the Second World War was being fought. He later called the book his war effort. Routledge published it in two volumes in 1945: The Spell of Plato and The High Tide of Prophecy, which deals with Hegel and Marx. In Spain it is published by Paidós as La sociedad abierta y sus enemigos.

It is a long, angry and very readable book. Popper goes after three of the most admired thinkers in the Western canon and accuses them of supplying the intellectual equipment of totalitarianism. Many classicists rushed to defend Plato, and they had a point: Popper reads him without much historical charity. The core of the book has survived those quarrels, and it is the part radical centrism uses every day.

The two enemies: prophecy and blueprints

The first target is historicism, the view that history is governed by laws or principles, so that whoever understands them can predict where society is heading. Popper found this belief in Plato's story of decline, in Hegel's march of the spirit and in Marx's laws of capitalist development. Popper treated this as prophecy dressed up as science: a theory of the whole of history can't be tested, and the claim to know where history is heading has served, again and again, to justify sacrificing people today for a promised tomorrow.

The second target is what he calls utopian engineering: remodelling the whole of society according to a definite plan or blueprint. The utopian picks the ideal end state first and then works backwards. Popper's complaint is practical as well as moral. A plan for everything can't be tested, because when it goes wrong there are too many moving parts to know why. And since the blueprint is supposed to be right, the people who object to it become obstacles. Utopian engineering slides towards silencing critics.

Against both he sets piecemeal social engineering, a phrase the Stanford Encyclopedia of Philosophy calls rather unfortunate, since it sounds like technocracy. The idea is modest and powerful. Find a specific evil that people suffer from, design a limited reform to reduce it, watch what happens and correct course. In the Internet Encyclopedia of Philosophy's summary, the piecemeal method permits repeated experiments and continuous readjustments. It brings the logic of Popper's philosophy of science into politics: we learn by making conjectures and looking hard for the evidence that they are wrong.

A better question than "who should rule?"

The most useful move in the book is a change of question. Since Plato, political philosophy had asked who should rule: the wisest, the best, the workers, the people. Popper thought the question invited disaster, because every answer assumes the right rulers can be found and then trusted. He proposed asking how political institutions can be organised so that bad or incompetent rulers are prevented from doing too much damage.

From that comes his definition of democracy. It is a nonviolent, institutionalised and regular way to get rid of bad rulers. A government that can be removed without bloodshed is democratic; one that can't is a tyranny, whatever it calls itself. The open society is an association of free individuals who respect each other's rights and can criticise how they are governed. The closed society is tribal, treats its rules as fixed and beyond question, and leads towards totalitarianism.

The book had a long life outside philosophy. George Soros named the Open Society Foundations after it; the organisation's own factsheet says the name reflects Popper's influence on its founder.

What radical centrism takes from Popper

Each tradition finds something in Popper. The left has always held that public power exists to fix concrete injustices and that citizens must be free to criticise those who wield it, and Popper's piecemeal engineer is someone who uses the state to reduce real suffering. The right and the liberal market tradition take his distrust of master plans and central planning, his defence of individual freedom and his humility about how little any government knows. The idea that fits neither camp is the one radical centrism builds on: every policy and every institution is a hypothesis. It has to be designed so that its mistakes show up, can be corrected, and so that those who made them can be removed peacefully.

That turns Popper into a working test for this week's subject, Spain's institutions. Democracia 21, whose launch speech we have mapped here, asks for a depoliticised judiciary, a prosecution service that answers to Parliament, specialised corruption courts and the end of aforamiento, the special court for politicians. Popper would ask the same thing of each one. Who can detect a mistake here, and who can correct it? When a judicial council stays frozen for five years because two parties can't agree, the system has lost its ability to correct itself. When the head of the prosecution service is chosen by the government it may have to investigate, the critic and the criticised are too close. When a politician's case goes to a different court from everyone else's, citizens have reason to doubt that the rules apply equally.

The Popperian answer is to design each institution so that it can be checked and its officials replaced through rules decided in advance. It also means treating our own proposals the same way. A reform of the judges' council or of the prosecution service should come with a date for evaluation and the evidence that would show it failed. That is what we try to do in today's pieces on the judicial council, the prosecution service, anti-corruption courts and aforamiento.

Popper also gives radical centrism its temperament. Moderation for its own sake has nothing to do with it. Popper was radical about method: he wanted reform to be continuous, and he wanted every belief, including his own, exposed to criticism. A movement that claims to combine the best of left and right needs exactly that habit, because it will get some combinations wrong, and it needs institutions that tell it so in time.