Professor Kukathas: “If the revolution advocated is a spiritual transformation, what is one to make of the authoritarian element of the manifesto? It sounds like the new society is going to have an awful lot of confiscating, and forbidding – stopping people from exporting, or fracking, or building up capital.”

“I’m sure Mr Brand’s heart is in the right place. I’m now less confident about his head. It looks to me that he has not produced anything more than an entertainment. That is a pity, because artists can do more than entertain if they are genuinely thoughtful.”