I use the word repugnance to describe transactions that some people would like to engage in, that other people would not like them to; it's often hard to pin-down what harm the transaction does to anyone else.

Among future technologies that may pose significant existential risks I would rank machine super intelligence at or near the top.

One of the most precious aspects of Glastonbury is specifically that we can't put our finger on it. It's evolved slowly over 50 years to become what it is today – we've tried things that have worked, some have not, and allowed it to evolve.

We need to change our hearts and minds, not just our behaviours. Forget even the moral argument, discriminating is such a waste. It is from our diverse cultures and communities that we could find the cure for cancer, where we could find all of the solutions for some of our most pressing problems.

I don't know why I didn't just walk-away from Los Alamos...

Technology is systematically undermining human weakness, the costs are huge. This is what degrades our quality of life and how we make sense of the world. This is what destroys our ability to form identity, to form relationships and make choices.

Unless women have the chance to take up an active role in our economies and fulfil their potential, our ambitions for a fairer and more prosperous world simply won't be realised.

When it comes to the growth of knowledge, you need to double down on the capacities you already have; you want to build on cities that possess a foundation. When you build in a remote location, costs skyrocket, attractiveness is hard to engineer, and the complementarities that help knowledge stick to a place simply aren't there.

99.9% of the time, you are not in a burning building- and that is precisely the time to think about what you would do in that 0.1% of time when it is on fire.

The printing press helped democratise Europe by providing space for discussion and agreement among politically engaged citizens, often before the state had fully democratised.

Sometimes it doesn't matter if the other side doesn't care about fairness; provided you do, you explain what's going on. I'm now playing his game and I pick something that's arbitrary. And now it's arbitrary vs. arbitrary versus principle versus arbitrary.

You have to take bullsh** and turn it into fertiliser.