As Science Began

How the self-taught Leeuwenhoek helped give birth to the scientific method, especially peer review.

In the 1600's, Western Europe was poised on the edge of the Enlightenment. Copernicus and Galileo had upset the old order and Newton had not yet established a new order. Looking back, we can see that the lines between science, superstition, and pseudo science were neither bright nor clear, especially in the universities.

Newton's alchemy cannot be isolated from Newton's science. In 1942, after reading the million words that Newton wrote about alchemy over two decades in until recently unpublished journals and personal notebooks, John Maynard Keynes told the Royal Society Club that "Newton was not the first of the age of reason. He was the last of the magicians." To the many followers of Descartes at the time, Newton's concept of "gravity" was too insubstantial, almost mystical, not mechanical enough.

Newton, along with the most learned academics, struggled to reconcile the received wisdom of the ancient texts to the perceived world around them. Aristotle, the Bible, and Hermes Trismegistus (image at right) told them one thing. Their telescopes, microscopes, prisms, and mathematical calculations told them something else.

At the Birth of the Scientific Method

What about Antony van Leeuwenhoek? To what extent was he a scientist, a man of empirical reason and not a "conjurer," as some in Delft called him, saying in a letter in 1677 "that I show people what doesn't exist"? To what extent was what he did science? That is, to what extent did he exhibit the behavior and values that we now associate with science?

Leeuwenhoek was also a man between worlds, the old world of scholasticism, alchemy, and superstition and the new world of rationality, science, and empiricism. We can assume that he knew the significance of what Galileo discovered and that he knew what had happened to Galileo as a result. During his life and even more since then, Leeuwenhoek has been denigrated as an amateur or as self-taught or even "the immortal dilettante" (L. M. Becking in Science Monthly, 1924). Why?

• He never developed a theory to unify or explain his observations.
• His observations, covering such a wide range of subjects, sacrifice depth for breadth.
• He never wrote a book.
• He had no students.
• He did not have a degree from a university.
• He did not even know Latin.

In other words, he did not have sufficient credibility for the old world of dogma and authority. However, he did have valid, reliable, original observations. He used a superior tool to become the first person to see and systematically record the microscopic world of protozoa and bacteria as well as many microscopic structures of the macroscopic world. He held values and practiced methods and techniques that are now associated with scientists.

In this definition, science is an activity, a method, a process for disproving hypotheses, for determining which ideas are right and which are wrong. This method has the following characteristics. The underlined terms are linked to the discussion below.

What makes science?

Leeuwenhoek's activity, as recorded in his letters over fifty years, exhibits all of these characteristics.

Leeuwenhoek's scientific activity

The Letters

The best way to learn about Leeuwenhoek's science? Read the letters!