I've seen it once. A person's face just after being told that she has tested positive. But I didn't see it just in her face. The pain and the shock was all over her body. Her feet were screaming, her arms were flailing desperately so as not to go berserk, despite the fact that they were hanging down by her sides.

It was a woman, and she can't have been more than twenty. It was in Maputo, in a private clinic of the simpler kind. I was there to check my blood pressure. I waited outside the closed door to the doctor's consulting room. It opened and the woman emerged. I knew immediately even though I didn't know: this young African woman had just been told that she was HIV-positive. She was just setting out on life, but had found that her time had been brutally cut short. Her life was coming to an end almost before it had started.

She walked away down the corridor. When they measured my blood pressure it was extremely high. The doctor frowned. But I told him it was only temporary. Something had happened shortly before I entered his room that had forced up my blood pressure. Now it was on its way down again.

I keep some people very close at hand, easily accessible in my memory. Aida is one, that nameless woman is another. I wonder very often what became of her, whether she is still alive.

There was once a famous library in Alexandria. It contained the sum of human wisdom, or as much of it as was recorded, on its shelves. Then it burnt down. Now, a few months before I go to Uganda, I pay a visit to the newly opened library in Alexandria. Architecturally, it is a remarkable creation. More of a cultural centre than a straightforward library. At the time of my visit an Austrian symphony orchestra is rehearsing in one of the halls.

While I am in Uganda it occurs to me that if all the memory books that are now being written could be gathered together, they might fill the library in Alexandria. There are so many memories to be written down, so many million little books will be left behind after the people who will shortly die from Aids. The vast majority of these millions of people will die too young. Most of their lives will be cut unjustly short. Many of their children, who are going to receive these books and are the reason why they are being written, will have been made homeless and will end up wandering aimlessly from continent to continent.

Then I have a vision: empty, abandoned libraries, and the great collections of books find themselves with no readers.

It is not a totally outrageous thought. Many a plot could be composed that would be just the thing for a science-fiction movie. There is already research which predicts that certain countries or regions in Africa south of the Sahara will be ruined if Aids continues to spread at the rate it is today. What they say should be taken seriously. The social fabric will be altered. A large percentage of the workforce will be wiped out, making society increasingly dependent on child labour. To make things yet worse, the whole existing intellectual heritage will be in danger of dying out because young people who are infected will not be able to raise the motivation for studies.

Wilderness, child labour, silence. Many people refuse to believe that this could happen. Or at least, think it is a threat that won't concern us for a very long time to come. But it takes only about nine hours to fly from the heart of Europe to the heart of Africa. In other words, a good night's sleep or a somewhat extended working day, and you are in the centre of what is threatening to become a wasteland, a return to the most primitive circumstances for work and property.

Some are already commenting on this in their memory books. There are people who are about to die, but who do nevertheless try to see into the future. They can comprehend the consequences of their own death, magnified and on a global scale. If there is one thing that is certain when it comes to Aids in Africa, it is that you will not die alone. Also it is true that your death will have very far-reaching consequences.

I read about this in several of the memory books. The fear of impoverishment, the fear that children will be left to their own devices, the fear that all knowledge will be forgotten, rot away like the dead body of a human being.

Aids has to do with many kinds of death. Hence also with many kinds of life. Obviously, life can be assessed and interpreted in the number of books that are written and the books that are read.

In 1343, Petrarch found a voluminous manuscript in Verona containing Cicero 's letters to his son Atticus: for many years the boy was an idle and unenthusiastic student in Athens. Those letters had been lost since Cicero 's time, since the beginning of our chronology. After thirteen hundred years they suddenly reappeared.

Is this what will happen to all the memory books that are being written today? It seems hardly credible that in our day and age it would be possible to bury the written word in archives, even as we bury nuclear waste in caverns deep inside mountains. But you never know.

There was once a great library in Alexandria. It contained all of human knowledge until it burnt down. Now it has been rebuilt.

Perhaps that library ought to be a centre for all the memory books that are being written today. Perhaps at least copies ought to be kept there, for the future.

In the diary I kept during my visit to Uganda there is a stray sentence scribbled down on the inside back cover.

The pain can be seen in their smiles.

Strangely enough, I have to admit that I can't remember when I wrote that. Who had I met? Whose smiles was I referring to? It seems to me odd that I can't remember. I would hardly have made a note like that without good reason.

I scour my memory, but I cannot find the occasion or the cause.

How can I remember a smile without remembering the face?

It wasn't until my last visit to Gladys that I realised that there was a link between her and Christine which I had not known about. Gladys told me when I first visited her that when she heard she had tested HIV-positive, she sat down and stayed sitting down for several years, doing nothing, only waiting to die. On that occasion, I overlooked the obvious question: what shook you out of that apathy?

It was Christine who persuaded her to abandon her apathetic wait for death.

Gladys and Christine knew each other only slightly, but Christine had heard that Gladys was sitting in her dark room as if paralysed. She never went out, hardly spoke to her children. She just sat there motionless, waiting for the cold breeze on the back of her neck.

One day Christine went to see her. She knocked on the open door and went in. Gladys' house has three rooms. In the first one, which was used as the best room, there were two armchairs with white embroidered throws over their backs. It was in one of those chairs that Gladys was waiting for death to call. She had been sitting there for more than three years. Every morning was a long wait for the evening. A wait for death. Christine entered the room and sat down in the other chair. She began by telling Gladys that she too was HIV-positive, but that she was unwilling to sit down and wait to die. Gladys didn't say much, so Christine talked all the more. She spoke about all Gladys' children, and her own children. Christine said that between them, they had a responsibility for seventeen children. They simply had to live for as long as possible, and never forget that despite everything, there could always be room for a smile on their faces. They had no right to sit down and wait for death. He would call when the time came, in any case.