It may sound crazy to pay people an income whether or not they are working or looking for work. But the idea of providing an unconditional basic income to every individual, rich or poor, active or inactive, has been advocated by such major thinkers as Thomas Paine, John Stuart Mill, and John Kenneth Galbraith. For a long time, it was hardly noticed and never taken seriously. Today, with the traditional welfare state creaking under pressure, it...