Every moral teacher or spiritual adviser gives injunctions about how to live wisely and well. But life is so complicated and full of uncertainty that rules seldom tell us quite what to do.

In every generation, there are quite firm rules on how to behave when you are crazy.

Every once in a while, something happens to you that makes you realise that the human race is not quite as bad as it so often seems to be.

It is so hard to make important decisions that we have a great urge to reduce them to rules.

Many of us will be obsessed with one or another kind of secret or revelation, be it gossip about friends or ourselves, a fantasy about spies, or a worry about the most personal information now stored in data banks. But few of us think about secrets in general, or about the moral rights and wrongs of hiding or exposing them.

The walking wounded, impaired in life and dissected in death, were our primary clues to where and how parts of the brain work.