What the scholars say

Most Leeuwenhoek scholarship has focused on his science, what he saw. Close examination of the Lens on Leeuwenhoek secondary print resources will show that most of these books and articles are written, mostly in English, by non-native Dutch speakers. Because there is no definitive corpus of all of Leeuwenhoek's letters let alone an English translation, these scholars use a translation that they do not have the expertise -- or cause -- to appraise let alone question. Since 1939, if the letter is in Alle de Brieven / Collected Letters, the Dutch and English there have been considered the standard, and rightly so.

After his observations, the other parts of Leeuwenhoek's career that draw scholarly attention are his tools and techniques. The scholarship in these areas is still predominantly by non-native Dutch speakers. The Dutch that Leeuwenhoek used matters little.

Scholarship on Leeuwenhoek's life is written mostly by native Dutch speakers, probably because the primary documents are in Dutch only. None of these documents, however, were written by Leeuwenhoek. We have only his letters.

When it comes to close analysis of Leeuwenhoek's letters, most scholars do not have access to the original hand-written manuscripts. Most are lost, and most of those that have survived are in the Royal Society's archives. They have no doubt been photographed, but with the exceptions on the left sidebar, those photographs are not publicly available. The translations in Philosophical Transactions are interesting, but tell us little about Leeuwenhoek's Dutch, of course. (Note: For Leeuwenhoek's very first letter in 1673, however, the Philosophical Transactions translation is all we have.)

Thus, for 165 letters, scholars work from the Dutch that Leeuwenhoek published in his lifetime, which he presumably proofread. For the rest, the texts come from transcriptions of handwritten manuscripts, usually in Leeuwenhoek's hand but sometimes the handwriting is that of someone else. Deviations from Leeuwenhoek's spelling and punctuation would tend toward uniformity. Who made the copies and transcriptions? For the copies, we do not know. For the transcriptions in Alle de Brieven / Collected Letters, however, two people can take all of the credit:

  • Judi Mendels made the transcriptions necessary for the first four volumes of Alle de Brieven / Collected Letters, along with the language-related footnotes.
  • B. C. "Kees" Damsteegt (1915-2003; right) took over for the final fifteen volumes.

When it comes to analysis of the language that Leeuwenhoek used in his letters, only native Dutch speakers have published in-depth studies, surveyed below. Damsteegt studied the letters in more detail, word by word, than anyone, when he made the transcriptions and wrote the footnotes. His 1965 article in Dutch on syntactic phenomena (syntactische verschijnselen) in Leeuwenhoek's writing, just short of 15,000 words, is by far the most detailed study of Leeuwenhoek's language. His 1982 article is the best English-language article about Leeuwenhoek's language.


"Simple and spicy"

P. J. Haaxman did not address Leeuwenhoek's language in his 1875 biography, though E. D. Pijzel, writing in the same year, called Leeuwenhoek's style and language "slovenly" or at best "untidy" (slordig).

Not every commentator judged Leeuwenhoek so harshly. Cornelis de Vooys devoted one paragraph to Leeuwenhoek in a longer 1913 article in De Nieuwe Taalgids about the development of a standard Dutch language in the 17th century. He compared the language of Leeuwenhoek to that of the more highly educated Johannes Swammerdam and measured them both against the rules for "correct" Dutch developed at the time by Arnold Moonen (note: all the translations below are mine):

With both, the grammatical 'correctness' of Moonen is still hard to find. [Leeuwenhoek] also does not join the purists of those days who deliberately repressed foreign words. One can, however, also apply a different criterion and ask whether the writer succeeds in clearly explaining his thoughts by means of his own language.

For me that weighs heavier than the external refinement. I prefer to read such a simple and spicy (pittig) seventeenth-century Dutch than the polished but often boring "book language" in the eighteenth century.


"City-hall Dutch"

In 1933, Gerrit Overdiep described Leeuwenhoek's writing style as a misunderstanding of "city-hall Dutch" (stadhuis-Nederlandsch), referring to the influence of the magistrates (schepenen) with whom Leeuwenhoek spent so much time after 1660:

[Leeuwenhoek] constantly confuses himself into endlessly intertwined sentences. All too often he loses the thread:

a clause does not find its conclusion in the expected main sentence;

a subject or object becomes detached from the accompanying saying;

demonstrative, especially reflective pronouns (terugwijzende voornaamwoorden) and adverbs have no logical antecedent;

a dependent clause with "that" incorrectly replaces other conjunctive clauses.

Overdiep followed that with a lengthy analysis of the language in Leeuwenhoek's letter of January 2, 1700, to Hans Sloane. Overdiep saw a Dutch language slowly evolving a literary standard that Leeuwenhoek, and many others, did not fully embrace:

I note that deviations from logic and sentence structure occur in all 17th century men and also in "developed" 20th century people. But not as much as with Leeuwenhoek. One can indeed call his Dutch, in view of the nature of his views and their purpose, "mauvais", that is, defective.

I would, however, like to say that this cannot be regarded as an insult or even as unkindness to this great man's address. On the contrary, his genius arouses our admiration even more when we can measure his language skills, that he must have been completely self-taught.


"Throbbing and glowing"

The first president of the Leeuwenhoek Commissie, Gerard van Rijnberk (right; click to enlarge), served from 1932 until just before his death in 1953. He oversaw the publication of the first four volumes of Alle de Brieven / Collected Letters, the editorial efforts of Gerard Heringa and Abraham Schierbeek. In 1933, Rijnberk set out the two earlier views of Leeuwenhoek's language: Overdiep's "defective"? or De Vooy's "simple and spicy"?

... must one forgive the genius of a man like Leeuwenhoek. Yes - one can in a sense enjoy his untidy word avalanches, in which the spiritus qui intus alit [ed: the spirit that nourishes within], the mind struggling with the difficulties of pure expression and the language laws not mattering, feels throbbing and glowing!

In this respect, I agree with Prof. De Vooys: When one reads Leeuwenhoek's prose and tries to analyze it grammatically, one gets confused every time and often does not understand what the man wants. But if one reads his writings with as much inquisitiveness and delight as with which he himself wrote them, then one will never have any difficulty in following him in his constructive meanderings.


"Complicated, sometimes inextricable sentences"

The article by Elisabeth Jongejan titled "Van Leeuwenhoek's brieven en de Nederlandse schrijftaal in de zeventiende eeuw" (Leeuwenhoek's letters and the Dutch written language in the seventeenth century) was written after the publication of the volume 1 of Alle de Brieven / Collected Letters but before the publication of volume 2. Jongejan compiled lists of hundreds of foreign words that Leeuwenhoek used that were not common in the elite literary Dutch being developed by influential writers. She noted that the letters in volume 1 were written to either Oldenburg or Constantijn Huygens. Leeuwenhoek, trying to impress them, used French words and wrote long sentences, especially in the opening and closing paragraphs of his letters to them.

Leeuwenhoek's sentence structure was influenced by his speaking language. How, then, to explain those many complicated, sometimes inextricable sentences and the many strange words in Van Leeuwenhoek's letters? We will have to assume that the autodidact Van Leeuwenhoek in his letters to the learned secretary of the Royal Society and the certainly no less scholarly Huygens has done his frenetic best to represent his observations and assumptions as accurately as possible in stately written-language sentences.

It would be interesting to follow up with a similar analysis for the letters in later volumes. Is it true, what Dobell claimed, that there was a "vast difference between the early letters and the last letters"? How did Leeuwenhoek's language change as he became a famous, more confident, and more practiced writer?


"Ordinary carelessness"

Since the middle of the 20th century, only two writers have dealt in detail with Leeuwenhoek's language. Judi Mendels transcribed the hand-written letters and annotated their Dutch for the first four volumes of Alle de Brieven / Collected Letters. She wrote three articles about Leeuwenhoek's language. The first discussed Leeuwenhoek's style in 1947.

[Leeuwenhoek] knew that he did not have a particularly well-maintained way of writing. Repeatedly, he apologizes about his 'style of pen' and tells us that he never applied himself to writing. However, he tries, especially in the beginning of his correspondence, to impress using foreign words, using very typically, often precisely those terms which are found in the English letter addressed to him, but otherwise he knows only one goal: to make the reader aware of what he has seen and to make his reflections understandable.

He thus so immerses himself in the account of his observations that he no longer cares about a pretty or grammatical-logical style, but constantly reintroduces new in-between sentences in order to tell everything very accurately, so that no misunderstanding is possible.

Her follow-up article a year later pursued Dobell's claim about the development of Leeuwenhoek's writing, but Mendels looked only at the spelling. She divided it into three periods: 1673-1683, 1683-1700, and 1700-1723.

Before 1683 Leeuwenhoek writes with the old spelling ... and a very clear Delft dialect. After that, his spelling is deliberately more regular, and this simplification continues until the next century. His dialect forms diminish and he gradually adjusts his language to the general Dutch language then coming into fashion. He finally writes this normalized language with a light Delft slant.

In volume 4 of Alle de Brieven / Collected Letters, Mendels's article about Leeuwenhoek's language discusses the richness of his images and comparisons and his use of "the average dialect of the town of Delft as spoken in his days by the cultured classes." Mendels gave the appropriate rhetorical terms, and examples, for three characteristics of Leeuwenhoek's syntax, all of which could confuse the reader.

  • Leeuwenhoek shifted in the middle of a sentence to a separate thought that required a different syntax, what the rhetoricians call an anacoluthon.
  • Sometimes, those separate thoughts were clauses complete in themselves and inserted into a sentence, what Mendels called "between sentences" (tussenzinnen). When he resumed the interrupted sentence, he sometimes forgot its logical context.
  • Leeuwenhoek would also blend two clauses, hinging them on a word that would be shared by both, what the rhetoricians call an apo koinou construction.

This is not only a consequence of ordinary carelessness, but rather a consequence of Leeuwenhoek's only knowing one purpose, viz. that of communicating to the reader as clearly as possible what he has seen and found; everything else pales into insignificance. ... a carelessness which can be explained from the fact that he considers style rather unimportant and entirely subordinate to his purpose, viz. to represent what he saw.

In this outwardly defective language we often feel the enthusiasm of the discoverer who forgets everything around him, and only wants others to share the joy which his find has given him.


"Lacked sufficient linguistic feeling"

After Mendels moved abroad, B. C. Damsteegt took over and finished the job of transcribing and annotating Leeuwenhoek's letters for Alle de Brieven / Collected Letters. The close-up of Leeuwenhoek's Letter 19 of March 23, 1677 (AB 31) to Henry Oldenburg (right; click to enlarge) shows his handwriting early in his career.

In his two articles about Leeuwenhoek's language, Damsteegt gave examples of five kinds of anacolutha, which Mendels had also discussed. He gave more examples of five types of Leeuwenhoek's sentences that revolved around participles. Both were "an indication that he conformed to the learned and solemn style of his time, which was influenced by Latin."

Damsteegt discussed features of Leeuwenhoek's writing which he called "characteristic of seventeenth-century Dutch in general":

  • subjects and verbs that don’t agree in number (singular/plural)
  • redundant double negatives

Leeuwenhoek's inconsistent punctuation made the sentence structure harder to understand:

Leeuwenhoek follows the system of four symbols (full stop, comma, semi-colon, and colon) which began to be universally adopted in the seventeenth century, but he did not do so very consistently. Undoubtedly he was not aware that he might make the structure of his sentences more intelligible for the reader by means of punctuation.

Damsteegt noted that the long and complicated sentences created syntactical confusion.

An important feature of Leeuwenhoek’s style is formed by the numerous long and very long sentences. Leeuwenhoek evidently never realized that it would make for greater clarity if he expressed himself in short, well-ordered sentences, and he lacked the aptitude to do so spontaneously. He also lacked sufficient linguistic feeling to construct all those long sentences faultlessly. In my study about his sentence structure l have pointed out some frequent imperfections.

In the end, Damsteegt balanced the challenges and the benefit of Leeuwenhoek's writing style. Leeuwenhoek placed the highest value on spontaneous expression.

In a sense it may be said that these faults are due to an important quality of Leeuwenhoek's style, viz. its spontaneousness.


The Sources below focus on Leeuwenhoek's use of the Dutch language.

The list of sources begins with the Dutch-English dictionary that Leeuwenhoek used, Henry Hexham's, and another that he probably used, Willem Sewel's. The edition of Sewel's dictionary published just after Leeuwenhoek's death reflects usage in the final part of his career. 

J. L. van der Gouw's Oud Schrift is a good place to begin for those wanting to wade into the thickets of primary sources, the 17th century documents handwritten in Dutch.

B. C. Damsteegt wrote two articles about Leeuwenhoek's language. The articles under his name in 1965, 1976, and 1981 are the same Dutch-language article. The 1976 printing is preceded by an English-language summary. The 1982 English-language article covers much of the same ground but is a different article.

The 2013 chapter by Felicity Henderson focuses on the Royal Society's translation of Leeuwenhoek's letters in London. See the page on Leeuwenhoek's translators on the left sidebar.

In his two-volume biography, Abraham Schierbeek seldom addresses Leeuwenhoek's language, so it is not included here.