Should we even have the classification system? Why shouldn't these things be open? There are things you want to keep secret, like the characteristics of your latest fighter plane or something like that.

Radical activists can't ignore the fact that we live in this world, like it or not, and have to make difficult decisions about which paths are the best - or sometimes, the least harmful. There are no abstract formulas. Have to think through each case on its own.

There is no reason to believe ... that the "essential purpose" of language is "communication". Language can be used to transmit information, but it also serves many other purposes: to establish relations among people, to express or clarify thought, for play, for creative mental activity, to gain understanding, and so on. In my opinion, there is no reason to accord privileged status to one or the other of these modes.

There is good reason to believe that we have already entered the Sixth Extinction, a period of destruction of species on a massive scale, comparable to the Fifth Extinction 65 million years ago, when three-quarters of the species on earth were destroyed, apparently by a huge asteroid.

It's this kind of wild unpredictability, megalomania, thin-skinned craziness that really has me worried, more than [Donald Trump] statements. Now, on the climate change there's just nothing to say, he's perfectly straightforward.

The human species is now at a point where it has to make choices that are going to determine whether decent survival is even possible. Environmental catastrophe, including war, maybe pandemics, these are very serious issues and they can't be addressed within the current structure of institutions. That's almost given. There have to be real significant changes, and only really effective popular mass-based movements can introduce and carry forward such initiatives, as indeed did happen during the 1930s.

Africa's a wreck and it's not because it was hit by an asteroid. It's a wreck largely because it was hit by Europe.