Just before Christmas I asked people on twitter to name a policy issue about which they’d changed their mind. The response was fascinating. First, because a few topics came up over and over: proportional representation, the justice system, austerity economics, Western interventionism and nuclear power. Secondly, because even though it turned into a thread with lots of political opinions, disagreement was for the large part civil and curious rather than aggressive and declamatory. That might be because of the type of person who’d engage with a question like that, but I also suspect the prompt put people in a more reflective and self-critical frame of mind.