Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.

The Heart of Gold fled on silently through the night of space, now on conventional photon drive. Its crew of four were ill as ease knowing that they had been brought together not of their own volition or by simple coincidence, but by some curious perversion of physics- as if relationships between people were susceptible to the same laws that governed the relationships between atoms and molecules

Arthur felt happy. He was terribly pleased that the day was for once working out so much according to plan. Only twenty minutes ago he had decided he would go mad, and now here he was already chasing a Chesterfield sofa across the fields of prehistoric Earth.

It is a well-known fact that those people who must want to rule people are, ipso facto, those least suited to do it... anyone who is capable of getting themselves made President should on no account be allowed to do the job.

How do you feel?" he asked him. "Like a military academy," said Arthur. "Bits of me keep on passing out.

We no longer think of chairs as technology, we just think of them as chairs. But there was a time when we hadn't worked out how many legs chairs should have, how tall they should be, and they would often "crash" when we tried to use them. Before long, computers will be as trivial and plentiful as chairs and we will cease to be aware of the things. In fact I'm sure we will look back on this last decade and wonder how we could ever have mistaken what we were doing with them for "productivity"

For as long as he could remember, he’d suffered from a vague nagging feeling of being not all there.