Friday

How did Robert Grosseteste and Roger Bacon—two illustrious medieval scholars—understand quia and propter quid demonstrations? How did they apply these forms of reasoning in their respective philosophies of nature? In this paper I address causes of motions of bodies as they were analyzed in medieval natural philosophy. Quia demonstrations consider the effect, and are correlated with the procedure of resolutio; propter quid demonstrations move from cause to effect and are correlated with the procedure of compositio.

While Grosseteste offered an outline of what may be referred to as scientific method, Bacon endeavored to actually use it. I therefore focus on Bacon’s method of geometrical diagrams, as applied in three case studies: (1) the motion of water towards the center of the universe; (2) the heat produced by naturally falling bodies; and (3) the swinging of the scale. Following Grosseteste, Bacon held that propter quid demonstrations ought to be formulated in geometrical terms. He argued, for example, that water flows toward the center because it seeks the equality of diameters, and that the diagonal motion of a falling body, caused by two opposite motive forces, is a cause of strain (and thereby heat), even when the motion is natural.

I ask whether Bacon’s geometrical diagrams, although defined by him as the heart of propter quid demonstrations, are in fact an analytical tool? A geometrical diagram is analytical because it involves the reduction of a certain physical phenomenon into simple geometrical components, and then the examination of their interrelations. If this was indeed the case, then either propter quid cannot be correlated with composito, but rather with resolutio (at least when it concerns Bacon and Grosseteste), or that Bacon conflated the terms. I proceed to examine the relation between geometrical principles and the natures or essences of the moving elements in what Bacon called propter quid accounts, thereby assessing the explanatory force of his geometrical suppositions. Once the propter quid demonstration is carried out, Bacon adduced the quia phase, by which the principle is confirmed by an appeal to experience. I will therefore examine also the interplay between fact (or “experience”) and theory in Bacon’s method.

This examination leads to a comparison between the two methods: the medieval quia/propterquid, and the early modern resolutio/compositio. I argue that although the methods are at the core similar, there are substantial differences in the meaning of some of their basic terms, in the ways they are applied, and in the epistemological status of the two phases, namely, resolutio and compositio.

Lavoisier’s gasometer is usually regarded as one of the most iconic instruments of the Chemical Revolution. In my presentation I shall examine the circumstances, both technical and theoretical, that are behind the making of this highly sophisticated machine. I shall show that the gasometer was constructed from several pieces of apparatus originally intended for experiments without direct connection to the analysis and synthesis of water. Moreover, some of the parts originated from already existing instruments and techniques (the enameller’s desk and the blowpipe) which were adapted and reinterpreted by Lavoisier. The history of the gasometer shows that, from the late 1770s, Lavoisier used his laboratory at the Arsenal as a collaborative experimentation site where, with the assistance of instruments makers, artisans, and colleagues from the Académie, he assembled and dissembled apparatus so it could be adapted for a variety of public experiments. 

Alchemical interpretations of Genesis were not rare in the Middle Ages, but Paracelsus paved the way for a rich, uninterrupted tradition of exegesis of the process, and Biblical story, of the Creation. Chymical processes were evoked to account for the creation of matter, including of course the process of separation. This exegetical current turned into a cosmology increasingly inspired by laboratory experiments, even when Paracelsians like Dorn, Severinus or Röslin offered alchemical readings of the Creation much more embedded in Platonic philosophy. One of the most spectacular developments of this tradition was the work attributed to the fictitious "Ægidius Gutmann": there, nearly every part of the first chapters of Genesis was submitted to chymical or mineralogical questions, as if the knowledge of Nature based on laboratory work offered the best explanation available to the Biblical text. Thus the story of Creation turned into a sort of experimental cosmology. Although the post-Tridentine Catholic Reform and its Protestant counterparts put quickly an end to these no longer tolerated overlaps of theology and natural philosophy, their influence remained strong within the alchemical tradition up to the eighteenth century.

The two most notable chymists of the early Académie Royale des Sciences, Samuel Cottereau Duclos (1598-1685)  and Wilhelm Homberg (1653-1715)  were both deeply committed to the project of correctly identifying the chymical principles in order to ground chymistry reliably and demonstrably. Both therefore struggled to develop sound and workable methods of analysis. Both, however, were frustrated by their inability--or perhaps the objective impossibility--of carrying out such an analysis in practice, and thus both turned to synthesis as a complementary procedure. Duclos resorted to observations of how mixed bodies were produced naturally and to alternative sources of knowledge. Homberg instead relied upon experimental techniques of synthesis in order to identify what he believed to be the central, but physically unisolable, chymical principle of all compound bodies. These cases showcase two responses to the frustrations inherent in experimental research programmes.

In 1862, Carl Regimius Fesenius announced the formation of a new chemical journal, the Zeitschrift für analytische Chemie by claiming that “it doesn’t take much effort to show that all the great developments in chemistry are linked directly or indirectly with new or improved analytical methods.” Fresenius’ new journal was the first specialized journal dedicated to a subspecialty of chemistry, but Fresenius’ claim for analytical chemistry suggests it lies at the heart of chemistry itself--all chemists are analytical chemists. Yet the subdiscipline of analytical chemistry emerged during the first half of the nineteenth century, alongside organic chemistry, and before physical chemistry, developing methods for identifying chemical species in, among other materials, minerals, mineral waters, and forensic analysis. This paper will explore the meanings of the term “analysis” and “analytical chemistry” as reflected in the dictionaries, handbooks and textbooks of the first half of the nineteenth century, with an eye towards how, and perhaps why, “analytical chemistry” separated from “chemical analysis.”

There has been a significant body of work that links the methodical procedures Descartes and Hobbes propose for the discovery of hidden causes of observed natural phenomena to the methods of analysis/resolution and synthesis/composition developed by late Scholastic Aristotelians. The scientific method Hobbes lays out in De Corpore, which includes an example of how one applies the method of analysis to discover the nature of gold, is commonly thought to resemble Zabarella’s regressus.  Descartes’ example of the magnet in the Rules to illustrate how one can methodically discover the mixture of simple natures that constitute the nature of the magnet suggest a similar procedure, though Descartes does not use the term ‘analysis’ in this context.  I will argue that though there are connections between late Scholastic methods of analysis and synthesis and the methodical procedures Descartes and Hobbes advance in natural philosophy, they are not as assumed in the literature.

This paper explores early-modern chymists’ claims to epistemic and cultural superiority rooted in the belief that experimental chymical analysis produced essential “things themselves” (res ipsae) -- principles, elements, or other foundational components of the material world -- that were perceptible by the human senses. This unique and immediate access to things themselves became a primary argument of Paracelsian and Helmontian chymists that was used to attack Aristotelianism and the mechanical philosophy, which was lambasted as speculative and abstract. In effect, for many chymists, the ability to analyze and identify the essential components of the material world became a hallmark of what it meant to be a chymist. Following a survey of chymists’ beliefs on the analysis and identification of principles and elements, I investigate the philosophical, cultural, and religious valences that helped to make analytical access to things themselves such a powerful and durable argument.