But life is glorious when it is happy; days are carefree when they are happy; the interplay of thought and imagination is far and superior to that of muscle and sinew. Let me tell you, if you don't know it from your own experience, that reading a good book, losing yourself in the interest of words and thoughts, is for some people (me, for instance) an incredible intensity of happiness.

Life would be impossible on such a planet. It wouldn't get enough heat and light, and if it rotated there would be total darkness half of every day. There wouldn't be any native inhabitants. You couldn't expect life - which is fundamentally dependent on light - to develop under such extreme conditions of light deprivation. Half of every axial rotation spent in Darkness! No, nothing could exist under conditions like that.

I type 90 words per minute on the typewriter; I type 100 words per minute on the word processor. But, of course, I don't keep that up indefinitely - every once in a while I do have to think a few seconds.

However, I continue to try and I continue, indefatigably, to reach out. There's no way I can single-handedly save the world or, perhaps, even make a perceptible difference - but how ashamed I would be to let a day pass without making one more effort.

Nothing has to be true, but everything has to sound true.

Writing is my only interest. Even speaking is an interruption.

During the century after Newton, it was still possible for a man of unusual attainments to master all fields of scientific knowledge. But by 1800, this had become entirely impracticable.