Scientists typically use a variety of representations, including different kinds of figures, to present and defend hypotheses. In order to understand the justification of scientific hypotheses, it is essential to understand how visual representations contribute to scientific arguments. Since the logical understanding of arguments involves the truth or falsity of the representations involved, visual representations must have the capacity to bear truth in order to be genuine components of arguments. By drawing on Goodman's analysis of symbol systems, and on Tarski's (...) work on truth, I show that the figures used in science meet this criterion. (shrink)

Molecular biologists and biochemists often use diagrams to present hypotheses. Analysis of diagrams shows that their content can be expressed with linguistic representations. Why do biologists use visual representations instead? One reason is simple comprehensibility: some diagrams present information which is readily understood from the diagram format, but which would not be comprehensible if the same information was expressed linguistically. But often diagrams are used even when concise, comprehensible linguistic alternatives are available. I explain this phenomenon by showing why diagrammatic (...) representation is especially well suited for a particular kind of explanation common in molecular biology and biochemistry: namely, functional analysis, in which a capacity of the system is explained in terms of capacities of its component parts. (shrink)

Abstract…observations of skylfull pylotts is the onlye waye to bring it in rule; for it passeth the reach of naturall philosophy. – Michael Gabriel, 1576 (Collinson, 1867, p. 30)Abstract The tension between empirical data and formal theory pervades the entire history of geomagnetism, from the Middle Ages up to the present day. This paper explores its early-modern history (1500–1800), using a hybrid approach: it applies a methodological framework used in modern geophysics to interpret early-modern developments, exploring to what extent formal (...) conjectures shaped observation and vice versa. A range of pertinent case studies supports classification of this entire period as proto-scientific, characterised by the initial formation of theories being largely disconnected from observational constraints, and their subsequent evolution being advanced primarily by their empirical falsification, and not necessarily associated with the introduction of an alternative. The few exceptional instances of purely data-driven discovery were essentially due to an improved signal-to-noise ratio. (shrink)

This article provides a strategic history of the role assigned by modern historians to visual representation in early modern science, an aspect of historiography that is largely ignored in the scholarly literature. Despite the current undervaluation of images and visual reasoning, historians in the 1940s and 1950s who established the 20th century concept of the Scientific Revolution, also assigned a conspicuous role to images, claiming 15th century art as a chapter in the history of science and identifying the first modern (...) scientists in artists such as Brunelleschi and Leonardo. My analysis of the writings that shaped the discourse on visual representation---by giants such as George Sarton, Herbert Butterfield, and Alexandre Koyré---shows that the handful of concepts introduced in these early discussions formed the foundations of the subsequent scholarly approach to early modern scientific images. However, close scrutiny during the 1970s defined these concepts as interesting but not as key elements for the emergence of modern science proposed earlier. The wave of social studies of science in the 1980s further diminished the importance of images, to the point that recent surveys of early modern science neither consider the role of visual representation nor include figures in their narratives. Several recent publications with suggestive titles such as The Power of Images in Early Modern Science promise to recover a significant role for images in the Scientific Revolution. The present inquiry into the earlier discourse seeks to clarify the historiographic framework into which these new efforts fit. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Ideas 62.1 (2001) 99-119 [Access article in PDF] Animism and Empiricism: Copernican Physics and the Origins of William Gilbert's Experimental Method John Henry In the second year of this journal's run, way back in 1941, appeared Edgar Zilsel's classic and still widely cited paper on The Origins of William Gilbert's Experimental Method. 1 Focusing on Gilbert's De magnete of 1600, undoubtedly a seminal text (...) in the history of the experimental method, 2 Zilsel argued that Gilbert borrowed his methodology from elite craftsmen, artisans, and other manual workers involved in mining, smelting, smithing, compass making, navigation, sailing, and other activities which involved working with iron or with magnets. 3 On its appearance the paper contributed to a growing and still continuing debate in the history of science about the relative importance of scholars and craftsmen in the origins of modern science. Although Zilsel's general thesis has been critically evaluated in terms of that wider debate, 4 his very specific claims about the [End Page 99] role of elite craftsmen in providing Gilbert with a ready-made experimental method, have never been properly considered. This paper attempts to reassess Zilsel's claims about the origin of Gilbert's experimental method and, in so doing, to arrive at a richer understanding of what Gilbert was trying to do in De magnete and to suggest an alternative source for his experimentalism.The first thing to note about Zilsel's argument is that it had two strands. 5 One of these pointed to actual experimental techniques used by Gilbert and showed that they can all be found in earlier writings on magnets. To be more specific, the techniques in question are to be found either in the thirteenth-century "Letter on the Magnet" written by Petrus Pergrinus or Pierre de Maricourt, first published in 1558, or in The Newe Attractive, a work on the magnetic compass written by a retired mariner, Robert Norman, first published in 1581 but reprinted three times before 1600. 6 The second strand did not involve experiments at all, with one notable exception, but simply implied or suggested that Gilbert's experimental techniques must have been inspired by miners and foundrymen, or navigators and instrument makers. The problem here, as others have objected, 7 is that it is by no means clear that elite craftsmen were engaged in performing experiments in anything like the sense of the word required for the argument to cut any ice. For Zilsel, however, "we cannot doubt that many of [the miners and foundrymen of the period], stimulated to improvements by economic competition, were wont to try new techniques and to observe natural processes." 8 A few sentences later we are told that it is "obvious" that "among such manual labourers there were experimentalists, though experimentalists with practical aims only and without theoretical knowledge." 9 [End Page 100]The philosopher of science at this point might legitimately want to suggest that an experiment is not an experiment unless it is testing a theory, but we do not have to enter into such arguable niceties. 10 We can see that there is something profoundly tendentious in Zilsel's claims simply by reading on. At this point Zilsel mentioned the only experiment specifically referred to in this strand of his argumentation. Quoting Gilbert, Zilsel showed that Gilbert himself must have descended into a mine in order, as Zilsel says, "to verify the hypothesis" that the polarity of a magnet derives from the polarity of the earth: We had a twenty pounds' heavy loadstone dug and hauled out after having first observed and marked its ends in its vein. Then we put the stone in a wooden tub on water, so that it could turn freely. Immediately the surface which had looked to the North in the mine turned itself to the North on the water. 11Zilsel did not make the absurd claim that Gilbert must have seen miners doing this kind of experiment, but he did all he could to... (shrink)

Despite recent work on scientific instruments by historians of science, the meeting ground between historians and curators of collections has been disappointingly narrow. This study offers, first, a characterization of sixteenth-century mathematical instruments, drawing on the work of curators, as represented by the online database Epact. An examination of the relationship between these instruments and the natural world suggests that the ‘theoric’, familiar from studies of the history of astronomy, has a wider relevance to the domain of practical mathematics. This (...) outcome from a study of collections is then used in re-examining an established question in the history of science, the position of William Gilbert on the motion of the Earth. (shrink)