I love the idea of bringing order out of disorder which is what the mystery is about. I like the way in which it affirms the sanity of human life and exorcises irrational guilts.

Human kindness is like a defective tap, the first gush may be impressive but the stream soon dries up.

There comes a time when every scientist, even God, has to write off an experiment.

For me, the dead remain dead. If I couldn't believe that, I don't think I could go on living.

If this were fiction, could even the most brilliant novelist contrive to make credible so short a period in which pride had been subdued and prejudice overcome?

Open your mind to new experiences, particularly to the study of other ­people. Nothing that happens to a writer – however happy, however tragic – is ever wasted.

I thought of inviting you to my other club but you know how it is. Lunching there is a useful way of reminding people that you're still alive, but the members will come up and congratulate you on the fact.