Overview: The Curious Observer

Meet Antony van Leeuwenhoek, cloth merchant and haberdasher, citizen of Delft, member of a growing, prosperous family.

Four hundred years ago, during the 1600's, the Dutch Republic was a soggy, overcrowded little country. A natural wetland, it had few resources other than peat and water, no forests, no mineral deposits. It did not have enough fertile farmland to feed the people born there let alone the immigrants pouring in from less tolerant countries.

Yet the Republic of the Seven United Provinces was quickly becoming the most prosperous and most learned country in Europe.

When Antony van Leeuwenhoek was born in 1632, the Republic had about 1.75 million people, a tenth of what it has today. The province of Holland had about forty percent of them, a third of whom lived not on farms but in the five largest cities. It was the most urbanized of the European states.

Vermeer's View of Delft, 1660, detail

In 1632, Delft, in the southern part of the country, was the fourth largest city. As one of the six cities that participated in the Dutch East India Company (the VOC - Vereenigde Oost-Indische Compagnie), Delft was fueled by foreign trade. It was filling with foreigners, who brought their skills, labor, and capital to manufacturing and crafts: textiles, ship and building construction, ceramics, and beer.

In the fall of 1632, two people were born in Delft who grew up with the liberty to pursue their visions. Johannes Vermeer (possible self-portrait on left) and Antony van Leeuwenhoek, both born into Dutch Reformed Church families, were baptized in the New Church just four days apart. Vermeer's visions gave us a pictorial record of life as it was lived then. Unfortunately, Vermeer died at 43 in 1675. What was the connection between them? The executor of his tangled estate was Leeuwenhoek, who while Vermeer painted had established himself as a retail cloth merchant and minor city official. (And, some scholars claim, perhaps sat for two of Vermeer's paintings.) His scientific career was starting just about the time Vermeer died.

Because of the worldwide market for all things Vermeer, we have many vivid and illustrated histories of Leeuwenhoek's Delft based on quite a bit of documentary evidence. Unfortunately, very little of it involves Leeuwenhoek by name. In the absence of direct evidence, we can infer much about his character from the several hundred letters that he wrote over fifty years. Conjecture has been repeated until a patina of plausible but unsubstantiated details has fleshed out the frustratingly few facts and documented events about Leeuwenhoek's life and work.

Constantijn Huygens wrote to Robert Hooke on August 8, 1673, that Leeuwenhoek was:

... a modest man, unlearned both in sciences and languages, but of his own nature exceedingly curious and industrious ... always modestly submitting his experiences and conceits about them to the censure and correction of the learned.

In addition to their "censure and correction", Leeuwenhoek apparently had to endure the condescension of the learned, too. That was only the beginning. For the next half century, until his death in 1723, Antony van Leeuwenhoek made little magnifying glasses, hundreds of them, and closely observed the world around him. What the Dutch Republic lacked in physical resources it made up for by developing its intellectual capital.

After his election as a Fellow of England's Royal Society in 1680, when he was 47, Antony van Leeuwenhoek entered the prime of his career. By then, he had seen red blood corpuscles and sperm cells in a variety of animals, including man, as well as what we now call protozoa and bacteria. He had written several dozen letters to the Royal Society, and excerpts from about half of them had been published in the Society's journal, Philosophical Transactions.

He didn't stop there. Over the next forty years, Leeuwenhoek sent several hundred more letters to the Royal Society. By his death in 1723, all or parts of almost a hundred and twenty letters had been translated and published in Philosophical Transactions in just over a hundred articles. Leeuwenhoek was their most published author, by far.

In addition, he wrote over a hundred letters addressed to the wide range of correspondents that his fame brought him. These letters were not published in Philosophical Transactions. Leeuwenhoek published these letters himself in Dutch and Latin.

Almost all of Leeuwenhoek's letters were accompanied by illustrations, and the letters referred to them. He employed artists (called teykenaars, limners or draughtsmen) to draw them. They were then re-drawn on copper plates by etchers in London for Philosophical Transactions and in Holland for his self-published volumes, and finally printed as reverse images on paper. Compared to the masterpieces that Robert Hooke drew himself for Micrographia, the drawings that Leeuwenhoek provided are informative but less elegantly drawn.


Under Sources are the full-length Dutch biographies by Haaxman, Dobell, Schierbeek, Smit et al., Van Delft, and Dekkers and the translations into English of Schierbeek and Smit (by Robertson). It also lists one long article with biographical details; it is also an Attachment. Still going strong draws on material from Lens on Leeuwenhoek.

The Tags section under Learn more has three links:

Antony collects the some of the pages on Lens on Leeuwenhoek that cover various aspects of Leeuwenhoek's life.

Overviews collects shorter general articles from the secondary literature.

Biography collects, in addition to the full-length bigraphies above, several dozen articles, chapters, and books in the secondary literature focused on one aspect of Leeuwenhoek's life or scientific career.