Newton published his deduction of universal gravity in Principia (first ed., 1687). To establish the universality (the particle-to-particle nature) of gravity, Newton must establish the additivity of mass. I call ‘additivity’ the property a body's quantity of matter has just in case, if gravitational force is proportional to that quantity, the force can be taken to be the sum of forces proportional to each particle's quantity of matter. Newton's argument for additivity is obscure. I analyze and assess manuscript versions of (...) Newton's initial argument within his initial deduction, dating from early 1685. Newton's strategy depends on distinguishing two quantities of matter, which I call ‘active’ and ‘passive’, by how they are measured. These measurement procedures frame conditions on the additivity of each quantity so measured. While Newton has direct evidence for the additivity of passive quantity of matter, he does not for that of the active quantity. Instead, he tries to infer the latter from the former via conceptual analyses of the third law of motion grounded largely on analogies to magnetic attractions. The conditions needed to establish passive additivity frustrate Newton's attempted inference to active additivity. (shrink)

Summary Based on Clausius’ phrasing of a “transformational content” and the resulting 2nd law of thermodynamics, I demonstrated that Gilbert Simondon’s On the Mode of Existence of Technical Objects is historically situated at the threshold of understanding open systems thermodynamics and the related concepts of balance. Furthermore, I showed that Gestalt theory, as represented by Wolfgang Köhler, at least reproduced, if not partially anticipated or even prepared this development of 20th century thinking. Finally, I gave some short examples of how (...) Simondon applied the figure/ground distinction to human perception, memory, and a general theory of becoming and I introduced his proposal to analyse “the grounds” just as thoroughly as the laws of figuration. (shrink)

Abstract During the Copernican revolution the supporters of the Ptolemaic theory argued that the tower experiment refuted the Copernican hypothesis of the (diurnal) motion of the earth, but was in agreement with the Ptolemaic theory. In his defence of the Copernican theory Galileo argued that the experiment was in agreement both with Copernican and Ptolemaic theory. The reason for these different views of the same experiment was not that the two theories were incommensurable, as Paul Feyerabend argues, but that Galileo (...) introduced a new theory of motion which he used as an auxiliary hypothesis in his discussion of the tower experiment, while those defending the Ptolemaic theory used the old Aristotelian theory of motion. Already before the Copernican revolution the Aristotelian theory of motion was criticized by philosophers in Paris, who suggested the impetus theory of motion. The later versions of this theory had the consequence that the tower experiment no longer refuted the hypothesis of the (diurnal) motion of the earth. Thus the impetus theory removed an old and important objection to the heliocentric theory. Galileo's inertial dynamics had the same function in the discussion of the tower experiment. (shrink)

: The work of Boris Hessen and Henryk Grossman on the emergence of early modern science is an attempt at a historical sociology of science and a historical epistemology of scientific knowledge. One of their theses is elaborated here, namely that early modern mechanics developed in the study of contemporary technology. In particular I discuss the thesis that the replacement of the Aristotelian concept of motion by the modern general and mathematical concept developed in the study of transmission machines. In (...) addition to a discussion of the thesis and its implications, I also present a case study to substantiate the thesis. I show that Benedetti's famous refutation of Aristotle and his introduction of a new concept of motion depended on empirical knowledge of the newly invented treadle mechanism. I argue that although the historiography of science since the 1930s has explored many of the individual issues first raised by the Marxist historians of science, this perspective remains unique in that it establishes direct and informative connections between the grand narrative of the transition from agrarian-feudal society to industrial production in early capitalism and the development of science and technology down to specific cognitive issues such as shared assumptions concerning the natural order. (shrink)