Suppose that we are wise enough to learn and know - and yet not wise enough to control our learning and knowledge, so that we use it to destroy ourselves? Even if that is so, knowledge remains better than ignorance.

Thinking is the activity I love best, and writing to me is simply thinking through my fingers. I can write up to 18 hours a day. Typing 90 words a minute, I've done better than 50 pages a day. Nothing interferes with my concentration. You could put an orgy in my office and I wouldn't look up-well, maybe once.

I even got a letter from a young woman in British Columbia that began as follows: 'Today I am eighteen. I am sitting at the window, looking out at the rain, and thinking how much I love you.'

I write for the same reason I breathe - because if I didn't, I would die.

Robots will neither be common nor very good in 2014, but they will be in existence.

Now remember, kids, the internet is serious business.

The young specialist in English Lit, ...lectured me severely on the fact that in every century people have thought they understood the Universe at last, and in every century they were proved to be wrong. It follows that the one thing we can say about our modern "knowledge" is that it is wrong.