Everybody wants breathable air, a healthy population, civil and consensual politics. We want a peaceful world, a stable economy. We've always wanted these things. The fundamental point of politics is to deliver them. And yet clearly our political systems are failing. Why is it so hard to get - and keep - the world that we want? The answer is that politics produces a number of traps: democracy, equality, solidarity, security and prosperity. We want democracy but if everybody's voice was given equal weight, we would never make a decision. We want equality but we are reluctant to give away our own wealth. We want solidarity but we are much better at receiving than offering it. We want security but not if it constrains our freedom. And we want to end the climate crisis but we also want a prosperous economy. In every case we want a collective goal but are undermined by our individual actions. Our aims are altruistic, our actions governed by self-interest.