Unlike us, machines do not have a 'nature' consistent across vast reaches of time. They are, at least to begin with, whatever we set in motion - with an inbuilt tendency towards the exponential.

From exam grading to health education to professional training to democratic participation, paths towards self-realization and success in the world are often daunting and obscure: journeys only the privileged feel confident setting off along.

The biggest neurological turn-on for people is other people. This is what really excites us. In reward terms, it's not money; it's not being given cash - that's nice - it's doing stuff with our peers, watching us, collaborating with us.

Censorship, like charity, should begin at home, but unlike charity, it should end there.

Modern motor vehicles are safer and more reliable than they have ever been - yet more than 1 million people are killed in car accidents around the world each year, and more than 50 million are injured. Why? Largely because one perilous element in the mechanics of driving remains unperfected by progress: the human being.

Over tens and hundreds of thousands of years, we evolved to find certain things stimulating, and as very intelligent, civilized beings, we're enormously stimulated by problem solving and learning.