In the last 30 years, historians of science have shown an increased interest in Isaac Beeckman's physical-mathematical approach to mechanism in the context of the ‘Scientific Revolution’. What we know about Beeckman comes from his notebook that reports his thoughts about experiments, tools, and scientific theories, which he discussed with his circle of friends including Descartes, Gassendi, and Mersenne, among others. However, Beeckman was not only a learned engineer, he was also trained in medicine, and obtained a medical degree from the University of Caen in Normandy in September 1618. He began to study medicine in 1616 in preparation for the dissertation defence at Caen, mostly by reading medical treatises at his hometown, Middelburg. At that time, Beeckman likely had access to these books through the library of his friend Philippus Lansbergen (1561-1632), a Dutch astronomer and Calvinist minister who lived in Middelburg from 1613. Among Beeckman's early medical sources, one can find – aside from Galen – a significant number of Dutch and French authors. In fact, Beeckman's first mention of a medical treatise points to the Universa medicina of the French physician Jean Fernel in 1613-1614, which he continued to study until at least 1621.

Beeckman's first inclination for French medical literature – as evidenced by the references to Fernel, Joseph du Chesne, Jean Tagault, Jean Riolan the Elder, and Guy de Chauliac – might have prompted his choice to obtain a medical degree in France.

The study of Isaac Beeckman's mechanical philosophy began in the early twentieth century in the margins of the study of Descartes and Mersenne. It also began in the context of the early professionalization of the history of science. Beeckman's editor, Cornelis de Waard, after all belonged to the first generation of specialized historians of science. In the second half of the twentieth century the study of Beeckman's work was emancipated from the study of Descartes. Beeckman emerged as a pioneering contributor to the new mechanical philosophy in his own right, and this volume shows that the study of his ideas about nature is by no means exhausted. Yet, in the context of the social history of science and the newer history of knowledge, in the late twentieth and early twenty-first century Beeckman has gained more significance as a crucial witness not only to revolutionary developments in natural philosophy. His Loci communes have also become testimony for the ‘otherness’ of the local, regional, and trans-European knowledge cultures that preceded the new science that emerged with Descartes and Newton. His lack of interest in communicating his work in print has long had a marginalizing effect on the role awarded to him in the shaping of the new science, that is, in the lineage from the well-published Descartes to Newton. Ironically, it is precisely because of his manuscript book that Beeckman is emerging as an interesting case in the new history of knowledge. The Loci provide great material for those interested in ‘knowledge-in-the-making’ rather than ‘ready-made-knowledge’, to quote Bruno Latour. They bristle with notes that allow us to peak into knowledge-making practices, the evolution of rules for such practices, and the interactions of a wide range of ‘knowledge-makers’ that often remain invisible or difficult to trace. Several contributions to this volume show how the Beeckman studies can be expanded beyond the big questions related to the rise of the new science, using those notes. Building upon those contributions, Beeckman's Loci can become crucial evidence in writing cultural and social histories of the world before the new science emerged.

Of course, the study of these wider cultures of knowledge through Beeckman's testimony should not divert from the study of the man, his work and his legacy, which is also far from exhausted.

Introduction

Isaac Newton (1642/1643-1727) owes his principle of inertia to René Descartes (1596-1650), who owes his principle of conservation of motion (PCM for short) to Isaac Beeckman (1588-1637). Thus, if the importance of Descartes for the history of physics is immense, that of Beeckman is no less significant. But, just as Newton hid his debt to Descartes, so Descartes hid his debt to Beeckman. This is the story of the principle of inertia that is currently being told by historians of science. I intend to show that it is possible to tell another one. This chapter will not look at Newton's debt to Descartes. It will look at Descartes’ debt to Beeckman. Indeed, after having examined the reasons why historians of science currently think that Descartes owes his PCM to Beeckman, I intend to show why Descartes may rather owe it to the Coimbrans, whose commentaries on Aristotle's Physics and On the Heavens – in which the PCM is several times explicitly used – he studied at La Fleche in 1612-1613.

Definition

Before I begin, I would like to make a few remarks concerning the PCM: 1) by PCM, I do not mean the Cartesian principle according to which God conserves the same quantity of motion in the world; 2) by PCM, I do not mean the principle of inertia:

Introduction

Sometime in the winter of 1618-1619, the 30-year-old philosopher Isaac Beeckman, who was staying in Breda to help an uncle and court a young woman, turned this topic of conversation into a ‘problem’ of natural philosophy by logging it in his Loci communes and reflecting upon its causes. This notebook, which according to humanist pedagogical practice he had been keeping since the age of sixteen, had by then developed from a compilation of reading notes (commonplaces) into a set of comments on problems that he encountered while reading, engaging in conversations or in observations of all sorts. Regularly, when he theorized about causes, the note taking became fully-fledged philosophizing in the sense of developing a philosophical theory on causes of natural phenomena.

In this volume we have brought together more than a dozen new studies about the Dutch natural philosopher Isaac Beeckman (1588-1637). Today, his important role in the initial stages of the Scientific Revolution of the seventeenth century is contested by no one, if only because of his decisive influence on the young René Descartes. Yet, the origins of Beeckman's innovative ideas about the constitution of the natural world and the mechanisms that lay behind natural phenomena deserve more historical investigation. Also, the social and cultural context in which he operated and which partly shaped his ideas and practices awaits further scrutiny. Moreover, his notebook and his particular way of philosophizing shed new light on the cultures of knowledge in the early seventeenth century, especially in the Dutch Republic. By exploring all these different issues, by extending the research into areas that were previously underexplored, and by re-thinking categories of thought that have been taken for granted for too long, we hope that this volume will contribute to a better and richer understanding of the early modern history of knowledge.

On the final pages of the previous chapter, John Schuster undertook a delightful exercise in ‘as if’ history. In the present chapter I take up the idea by imagining Beeckman to accept an invitation by the Royal Society to detail his relationship with the late René Descartes.

Domini praeclari, Most learned Fellows of the Royal Society for the improvement of naturall knowledge by Experiment (it is, to say that right away, not clear to me how experiments could possibly help us improve our understanding of the natural world).

At the age of 80 back in your country for the third time, it is my honour and my great pleasure to stand in this festive hall at Gresham College and to consider from a variety of viewpoints the topic that you have invited me to address. What are the origins, as I see them, of what you here in Britain have of late accustomed yourself to calling ‘the mechanical philosophy’? To be more specific, the wording of the very flattering letter that your most diligent secretary, Mr. Henry Oldenburg, Esq., has sent me leaves some room for the suspicion that your innocent-sounding question is really aimed at learning how, if asked, I would assess my own scholarly achievement in comparison to that of the man meanwhile known all over Europe as the great pioneer of the mechanical philosophy – my regretted friend, the late René Descartes.

Riding Orders: ‘What Was Beeckman Doing – in the Context of the Scientific Revolution?’

I have been concerned about Isaac Beeckman as a figure in the Scientific Revolution for just short of 50 years, having begun to read his Latin writings on mechanics in 1971, under the guidance of the late Michael S. Mahoney in the Princeton History of Science Program. Mahoney and I started terming the early mechanists such as Beeckman, Descartes, Hobbes and Gassendi, ‘corpuscular-mechanists’. Stimulated by another faculty member, Theodore K. Rabb, we began to think of the generation in which corpuscular-mechanical natural philosophy was invented as the critical stage in a multiphase process of the Scientific Revolution. Mahoney pointed out to me that in 1618 Beeckman had recalled the young Descartes to study, including the study of corpuscular-mechanical natural philosophy. Later, in my doctoral dissertation, the Beeckman/Descartes relationship covered 80 pages out of about 750.

However, I am not a fully-fledged Beeckman scholar. Believing in the importance of Beeckman in the Scientific Revolution and having a particular interest in his relations with Descartes, I have had a watching brief on Beeckman scholarship. When the organizers of the Middelburg Beeckman conference invited me to deliver a plenary lecture on the topic that is now the title of this chapter, I requested more guidance about my assignment. Klaas van Berkel asked me: ‘What do you think Beeckman was doing?’ My answer in the plenary talk and this chapter is that Beeckman was practising natural philosophy, in a novel register.

The telescope was crucial in bringing about a methodological shift in seventeenth-century natural philosophy. It legitimized the use of observational aids in the study of natural phenomena, and thus furthered the very role of observation in seventeenth-century inquiry. Nonetheless, many questions about its emergence, and its interaction with the evolving science of optics, remain unanswered. Isaac Beeckman's notes carry all the potential to shed light on a uniquely early and local reception of the telescope. In this chapter I will analyse how Beeckman gradually developed an understanding of the working principle of the telescope.

My analysis partly picks up on the recent historiography of the telescope. I will argue how Beeckman's familiarity with late-sixteenth-century optical innovations is larger than his modern editor, Cornelis de Waard, assumed. Still, if these innovations in optics were characterized by an increased attention for the mechanism of refraction of light in lenses, Beeckman's understanding of the telescope was only partially embedded in these. From his first notes onwards, Beeckman's reasoning based on refraction was complemented with a working principle resulting from a physical interpretation of the agents of vision, species, borrowed from other branches within the multifaceted sixteenth-century optical tradition. In Beeckman's early notes, these distinct contributions blended into a coherent whole. Interestingly, it was chiefly his physical interpretation of species that Beeckman subsequently merged in his maturing mechanistic ideas, arriving at a conception of the telescope that was original, and that was surprisingly adequate, too. It allowed Beeckman to understand the telescope as a device that brings remote things nearby, rather than an instrument that produces larger images.

On 6 September 1618, Isaac Beeckman received his doctorate in medicine from the university of Caen. Although Beeckman pursued a number of occupations in his life, such as candle maker, schoolmaster and lens grinder, the received opinion is that he never really put his medical degree into practice and that his medical interests were mainly theoretical. This is illustrated by the many notes in the Journal on medical disputations, often in relation to his developing mechanical philosophy of atomism. However, apart from writing about medicine from an exclusively theoretical angle, Beeckman also engaged with illness and bodily ailments he encountered during his everyday life, including a few cases in which he himself was the patient. Considering the fact that he was a trained man of medicine, the question arises: in what manner did Beeckman write about his everyday aches and illnesses? Did he follow the common narrative of many patients at that time, or was he primarily looking at himself, and perhaps even others, through the lens of a trained physician?

The study of lay perceptions of illness and medicine, in addition to the common approach to the physician's view, has become a major subject in the field of medical history since Roy Porter's famous 1985 article ‘The Patient's View: Doing Medical History from Below’.

Introduction

Throughout the Middle Ages, Latin had been the dominant language of learning and knowledge in Europe. Any conversation between educated men, and occasionally women, about learning or about science would be conducted in Latin. Its dominance remained the standard in the sixteenth and seventeenth century, although it gradually received more and more attention. Around the beginning of the sixteenth century, the functions of language in general and the relationship between Latin and the vernacular languages in particular developed into a significant and critical subject of discussion for religious and social reformers. At this time, multilingualism was not a new concept; Europeans were accustomed to the many different dialects and languages within and between the countries of Europe. Around the second half of the sixteenth century, however, these encounters with various languages sparked something described as a ‘fascination with language’. The Latin language, in particular, received increasing attention in these changing views. It became a popular idea to look at the riches and poverty of a certain language and to compare these to those of other languages. The comparison between a vernacular language and Latin generally resulted in an emphasis on the poverty found in the former in terms of vocabulary. In order to tackle this, some proposed to borrow words from different languages, while others preferred to invent new words.

Isaac Beeckman played a significant role in the history of science, since he devised a physico-mathematical philosophy to investigate nature that influenced, if not inspired, René Descartes amongst others. Yet, Beeckman's role in the history of science should not be restricted to his precarious relationship with Descartes. On the contrary, he held a pivotal position that lays bare an important attempt to account for natural phenomena and bodies within a systematic theory of mathematical physics. His Journal (written between 1604 and 1637, and published in its entirety only in 1939-1953) is a useful source for unearthing the attempt to apply a systematic theory of mathematical physics to the study of nature. In other words, his natural philosophy combines mechanical ingenuity and mathematical methodology with a theoretical view. By means of his method, he fostered, if not anticipated, the modern approach to nature. In this sense, Beeckman was a son of his country. The Dutch Provinces of the time were a laboratory of practices and ideas and a crossroads between cultures, systems, and knowledge, as Delphine Antoine-Mahut and Catherine Secretan have recently shown.

Moving from these premises, in this chapter I explore Beeckman's focus on plants, one of the less-studied subjects of his broad range of interests. Although Beeckman may not be defined as a botanist nor as a botanical virtuoso in a strict sense, his attempt to deal with vegetation within his corpuscular, atomistic, and mechanical theory importantly surfaces in a few notes in his Journal and significantly anticipates a modern understanding of the vegetal realm of nature.