Li Shizhen's Book of Medicine

Hold two pictures in mind, and then set them side by side.

The first is a footpath slung across a mountainside, in the days of the Ming, the dynasty then ruling China. A middle-aged man in a faded cloth robe stops beside a woodcutter who has just set down his bundle of firewood to rest. He is not asking the way. He reaches out, picks a sprig of leaves from the grass by the path, and holds it up. Then he asks plainly what people around here call this, which slope it likes to grow on, and whether the young leaves differ from the old ones. The woodcutter wipes the sweat from his face as he answers. The man takes out paper and a brush and writes down every word.

The second is a wooden rack in a printing shop in Jinling, the city now called Nanjing. On the rack sits a set of books just off the press, the ink still fragrant, 52 volumes stacked one on another. The cover bears four characters: Bencao Gangmu, the Compendium of Materia Medica.

The gap between those two pictures is the whole story. The man on the mountain path was named Li Shizhen. And by the day that set of books was placed on the rack, he had been dead for three years.

He was born in 1518, in Qizhou, in the region of Hubei. His family had practiced medicine for three generations. His father, Li Yanwen, was both a healer and a learned man. In those days, the brightest road for a clever boy was to sit the examinations and become an official. His father hoped for that. The son tried hard, too. But he was often sick, and three times he sat the provincial examination, and three times he came home empty-handed. After the third time he gave it up for good and asked his father to let him follow the family trade.

That trade rested on handwritten books passed down from the distant past, the oldest of them Shennong's Classic of Materia Medica. The more Li Shizhen read, the more uneasy he grew. The books did not agree with one another. The same plant had one name in this volume and another name in that one. Copied and recopied for hundreds of years, the texts drifted further from the original with every copy.

So he set out to do something very large. Not to copy the old books into a tidier form, but to go and see for himself, and only then write.

And go he did. On foot and by boat, climbing mountains and wading streams, from one region to the next. In his cloth bundle he carried only paper, a brush, and a patience that is hard to believe. But what stays in the memory most is whom he went to see. Not the officials at court, but people who lived with the land all year round. The farmer out in his field. The woodcutter up on the mountain. The fisherman down at the landing. The people whose work was going deep into the forest in search of plants.

He asked them the local names. He asked when a plant flowered and when it dropped its leaves. Then he wrote down what they said, as carefully as he copied the words of the old books.

That is the finest part of it. Li Shizhen was an educated man, and most of the people he asked could not read or write. Even so, he believed someone who climbed the mountain every morning with a knife over his shoulder knew more about that plant than a yellowed page did.

Alongside the journeys, he read more than 800 books. He also went back over more than 40 medical works from earlier ages.

Then he sat down to write. When he had finished, he read it all again and felt the arrangement was not right. So he threw out the old structure and began again. Then he did it one more time. Three times he reworked the entire book, over 27 years of one man's life.

Twenty-seven years is a long time. By the time he set down the final dot, a child born on the day of his first line would have grown up, gone to work, married and had children.

The first draft was finished in 1578. Still he would not let go. He kept revising and adding until the last years of his life. The finished work filled 52 volumes. Together they held about 2 million characters. There were 1,892 entries, and 1,109 drawings went with them. Each entry was something he had studied and then given its own place: plants and grasses, earth and stones, the things that come from the forests and the rivers.

Writing a book and getting it printed are two different things. The manuscript waited. He waited with it. Li Shizhen died in 1593, before a single page had been printed.

His children and grandchildren saw the printing through. In 1596, three years after his death, the book came out in Jinling. The second picture had come true. The only sorrow was that the man who most deserved to stand in front of it was gone.

From that printing shop the book traveled far, to neighboring countries, and it was translated into many languages. In 2011 it was inscribed on UNESCO's Memory of the World register, a list of documents the whole world regards as shared heritage.

If you have ever stepped into a traditional Chinese medicine shop, the smell probably stays with you, and so does the wall of tiny wooden drawers, each with a handwritten label. That wall is a close relative of books like the Compendium of Materia Medica. Both are a way of putting the world in order, so that what is needed can be found.

And Vietnam was never just looking on from outside. It had people of its own who did exactly this work, as equals.

As early as the 14th century there was a Zen master named Tuệ Tĩnh. He lived under the Trần dynasty, which ruled Vietnam from 1225 to 1400. His birth name was Nguyễn Bá Tĩnh, and he came from the old region of Hải Dương. He passed the examinations but did not take up office. Instead he became a monk, and then a healer. The saying tied to his name, repeated for hundreds of years, is only five syllables long in Vietnamese. It means medicine of the southern land, for the people of the southern land. He compiled a book called Nam dược thần hiệu. It recorded the very things that grow along the hedges and the rice-field banks of Vietnam.

Nearly 400 years later came Lê Hữu Trác, also known as Hải Thượng Lãn Ông. He was born in 1724 and died in 1791. He too turned away from an official career. He went to live in his mother's home region, Hương Sơn in Hà Tĩnh, where he practiced medicine and wrote. The book of his whole life is called Hải Thượng y tông tâm lĩnh. It has 28 parts and 66 volumes.

And here is the detail that makes people fall silent. That book, too, was not printed while its author was alive. Only in 1885, nearly 100 years after his death, were the carved wooden printing blocks finally finished, at a pagoda in Bắc Ninh. A monk had stepped forward to raise the money. Those woodblocks are now a National Treasure, kept in the Bắc Ninh Provincial Museum. In 2023, UNESCO passed a resolution honoring Lê Hữu Trác.

Two men, two lands, born about 200 years apart, and yet they sat the same way. One lamp. One pile of paper. One man who wrote and wrote without finishing, and then left this world before his own book came out.

Now the two pictures sit side by side one last time. The mountain path, and the man in the faded robe holding up a sprig of leaves to ask the woodcutter, who is still wiping the sweat from his face. And the wooden rack in the printing shop, where the new set of books lies waiting for a man who will never come.

The two pictures are three years and a whole lifetime apart. But seen up close, they are really one picture. Every name in that thick set of books was once a very quiet question, asked of someone who could not read, on some nameless stretch of road, one afternoon a very long time ago.