Sometimes you get a glimpse of a semicolon coming, a few lines farther on, and it is like climbing a steep path through woods and seeing a wooden bench just at a bend in the road ahead, a place where you can expect to sit for a moment, catching your breath.

The drive to be useful is encoded in our genes. But when we gather in very large numbers, as in the modern nation-state, we seem capable of levels of folly and self-destruction to be found nowhere else in all of nature. But if we keep at it and keep alive, we are in for one surprise after another. We can build structures for human society never seen before, thoughts never heard before, music never heard before.

Music is the effort we make to explain to ourselves how our brains work. We listen to Bach transfixed because this is listening to a human mind.

I suggest that the introductory courses in science, at all levels from grade school through college, be radically revised. Leave the fundamentals, the so-called basics, aside for a while, and concentrate the attention of all students on the things that are not known.

I don't want to be reincarnated, that's for sure. When you've had rewarding experiences in your life - a loving family, friends - you don't need additional reassurances that you're going to do something with a new cast of characters. I'd just as soon pass.

It is not so bad being ignorant if you are totally ignorant; the hard thing is knowing in some detail the reality of ignorance.

My mitochondria comprise a very large proportion of me. I cannot do the calculation, but I suppose there is almost as much of them in sheer dry bulk as there is the rest of me. Looked at in this way, I could be taken for a very large, motile colony of respiring bacteria, operating a complex system of nuclei, microtubules, and neurons for the pleasure and sustenance of their families, and running, at the moment, a typewriter.