At the present rate of progress, it is almost impossible to imagine any technical feat that cannot be achieved - if it can be achieved at all - within the next few hundred years.

Trying to predict the future is a discouraging and hazardous occupation. If by some miracle a prophet could describe the future exactly as it was going to take place, his predictions would sound so absurd that people everyone would laugh him to scorn. The only thing we can be sure of about the future is that it will be absolutely fantastic. So, if what I say now seems to you to be very reasonable, then I will have failed completely. Only if what I tell you appears absolutely unbelievable have we any chance of visualizing the future as it really will happen.

That's one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.

In my life I have found two things of priceless worth - learning and loving. Nothing else - not fame, not power, not achievement for its own sake - can possible have the same lasting value. For when your life is over, if you can say 'I have learned' and 'I have loved,' you will also be able to say 'I have been happy.

If there are any gods whose chief concern is man, they can't be very important gods.

A man who grows that much hair,' critics were fond of saying, 'must have a lot to hide.

The fact that we have not yet found the slightest evidence for life - much less intelligence - beyond this Earth does not surprise or disappoint me in the least. Our technology must still be laughably primitive, we may be like jungle savages listening for the throbbing of tom-toms while the ether around them carries more words per second than they could utter in a lifetime.