: Scientific observation is determined by the human sensory system, which generally relies on instruments that serve as mediators between the world and the senses. Instruments came in the shape of Heron's Dioptra, Levi Ben Gerson's Cross-staff, Egnatio Danti's Torqvetto Astronomico, Tycho's Quadrant, Galileo's Geometric Military Compass, or Kepler's Ecliptic Instrument. At the beginning of the seventeenth century, however, it was unclear how an instrument such as the telescope could be employed to acquire new information and expand knowledge about the (...) world. To exploit the telescope as a device for astronomical observations Galileo had to: 1. establish that telescopic images are not optical defects, imperfections in the eye of the observer, or illusions caused by lenses; 2. develop procedures for systematically handling errors that may occur during observation and measurement and methods of processing data. Galileo made it clear that in order to measure and interpret natural phenomena accurately, a suitable method and instrument would need to be developed. It is intriguing, therefore, to regard the Galilean telescope in this light and to discover the linkage established by Galileo among theory, method, and instrument—the telescope. Although the telescope was not invented through science, it is instructive to see how Galileo used optics to employ a theory-laden instrument for bridging the gulf between picture and scientific language, between drawing and reporting physical facts, and between merely sketching the world and actually describing it. (shrink)

Many prominent arguments for epistemic relativism take their departure from the observation that a certain kind of epistemic symmetry is present in particular empirical cases. In this paper, we seek to attain further clarity about the kind of symmetry at issue, and the sort of relativism to which such symmetry can reasonably be taken to give rise. The need for such an investigation is made apparent, we believe, by the fact that prominent anti-relativist arguments such as that advanced by Boghossian (...) in his influential book Fear of Knowledge (2006) yield distorted pictures of the matter. Following Boghossian, we present our argument through a detailed consideration of the dispute between Bellarmine and Galileo concerning heliocentrism. Contrary to what Boghossian claims, the relevant sort of symmetry does not concern a difference in fundamental epistemic principles between Bellarmine and Galileo, but rather a much more localized difference in procedures for adjudication between shared principles in the novel epistemic circumstances generated by Galileo's telescopic observations. Bellarmine and Galileo advance fundamentally different procedures of adjudication that are nevertheless equally rational. The upshot is not so much the denial that there are absolute epistemic facts as such, as Boghossian thinks, but rather the denial that there is an absolute fact of the matter as to which was the most rational way to proceed: Bellarmine's or Galileo's. What this gives us, is the denial that there is a certain kind of absolute epistemic fact. (shrink)

: To honor Bernard Goldstein, this article highlights in the "Defense of Theon against George of Trebizond" by Regiomontanus (1436-1476) themes that resonate with leading strands of Goldstein's scholarship. I argue that, in this poorly-known work, Regiomontanus's mastery of Ptolemy's mathematical astronomy, his interest in making astronomy physical, and his homocentric ideals stand in unresolved tension. Each of these themes resonates with Gold- stein's fundamental work on the Almagest, the Planetary Hypotheses, and al-Bitruji's Principles of Astronomy. I flesh out these (...) tensions with an intriguing interpretation of the history of astronomy, in which Regiomontanus contrasts the two-dimensional "eccentric astronomy" attributed to the Almagest and the Arabs with the three-dimensional spheres of the "later" astronomers. A similar contrast reappears when Regiomontanus portrays as a "fictitious art" an astronomy that does not go beyond the accommodation of computations to the appearances. To conclude, I use Regiomontanus's expression to reinstate (pace Goldstein and Barker in this journal, 1998) fictionalism as an actor's category in Osiander and sixteenth-century astronomy. (shrink)

ArgumentThe purpose of this paper is to provide an analysis of Giordano Bruno’s conception of mathematics. Specifically, it intends to highlight two aspects of this conception that have been neglected in previous studies. First, Bruno’s conception of mathematics changed over time and in parallel with another concept that was central to his thought: the concept of infinity. Specifically, Bruno undertook a reform of mathematics in order to accommodate the concept of the infinitely small or “minimum,” which was introduced at a (...) later stage. Second, contrary to what Héléne Védrine claimed, Bruno believed that mathematical objects were mind-dependent. To chart the parallel development of the conceptions of mathematics and infinity, a seven-year time span is considered, from the publication of Bruno’s first Italian dialogue (La cena de le ceneri,1584) to the publication of one of his last Latin works (De minimo, 1591). (shrink)

Kepler's Somnium is a fantastical story about the world on the moon. It presents a heliocentric world-picture established through a total conversion of the meaning and place of observation in the hierarchy of knowledge. This epistemological program is construed through a critical adaptation of Lucian's "True Story," and Plutarch's "The Face on the Moon." Utilizing his new optics, embodied in the Camera obscura, Kepler inverts the meaning of these classical texts together with the reader's point of view. Astronomical knowledge is (...) vindicated and scientific observation is the only way out of an obscure and mannerist dream. (shrink)

This essay deals with Girolamo Fracastoro’s ensouled cosmology. His Homocentrica sive de stellis (1538), an astronomy of concentric spheres, was discussed by the Padua School of Aristotelians. Since the polemics over the immortality of the human soul, which had famously opposed Pomponazzi to Nifo, psychological discussions—including those about heavenly spheres’ souls—raised heated controversies. Fracastoro discussed the foundations of his homocentric planetary theory in a dialogue titled Fracastorius, sive de anima (1555). In a 1531 exchange with Gasparo Contarini, Fracastoro discussed celestial (...) physics, including problems linked to mathematical analysis of physical causation. Contarini expressed his doubts over Fracastoro’s lack of consideration of Aristotelian viewpoints on heavenly souls and intelligences. Fracastoro offered an account of cosmic animation in his later dialogue “On the Soul,” taking a different path than his Paduan teachers. He picked up the Platonic idea of the “world soul,” freely connecting it with Aristotelian views about the ensouled cosmos of concentric spheres, resulting in an eclectic composition of Platonic, Aristotelian, and Averroistic elements. Fracastoro grounded his renewed mathematical astronomy on an understanding of the cosmos as a living whole. His animated homocentric cosmos represented a development of Aristotelian premises and a step beyond this legacy. (shrink)

The early dissemination of Copernicus' work and theories is an intricate and multilayered history. The reception of De revolutionibus orbium coelestium, which was the first early modern work in mathematical astronomy introducing a heliocentric planetary theory, was not purely technical. Rather, the cultural debates surrounding it were affected by physical, philosophical, ethical, and theological concerns from its inception. Georg Joachim Rheticus, who authored the first report on Copernicus' achievement, deemed it appropriate to put a call for independence of spirit on (...) the title page of the Narratio... (shrink)

The aim of this paper is to take Galileo's mathematization of nature as a springboard for contrasting the time-honoured empiricist conception of phenomena, exemplified by Pierre Duhem's analysis in To Save the Phenomena , with Immanuel Kant's. Hence the purpose of this paper is twofold. I) On the philosophical side, I want to draw attention to Kant's more robust conception of phenomena compared to the one we have inherited from Duhem and contemporary empiricism. II) On the historical side, I want (...) to show what particular aspects of Galileo's mathematization of nature find a counterpart in Kant's conception of phenomena.------------------------------------------------------------------------------------------ ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- --------------------------------------------------. (shrink)

How does Newton approach the challenge of mechanizing gravity and, more broadly, natural philosophy? By adopting the simple machine tradition’s mathematical approach to a system’s co-varying parameters of change, he retains natural philosophy’s traditional goal while specifying it in a novel way as the search for impressed forces. He accordingly understands the physical world as a divinely created machine possessing intrinsically mathematical features, and mathematical methods as capable of identifying its real features. The gravitational force’s physical cause remains an outstanding (...) problem, however, as evidenced by Newton’s onetime reference to active principles as the “genuine principles of the mechanical philosophy”. (shrink)

When we examine the history of astronomy up to the end of the seventeenth century by considering the relation between mathematical astronomy and natural philosophy, it has been argued that there were two groups of philosophers and astronomers: instrumentalists and realists. However, this classification is deficient when we consider attitudes toward the explanatory power of mathematics in determining astronomical theories. I offer the solution of dividing realists into two subcategories—mathematical realists and physical realists. Mathematical realists include those who thought mathematics (...) could provide the real motions of celestial bodies. The physical realists, who include Ibn Rushd (Averroës), believed mathematics could not provide us with the real structure of the heavens. To avoid contradictions between the physical and mathematical models, the physical realists held that a mathematical model of the heavens should be designed by considering physics. I argue, in this article, that Francis Bacon can be considered a physical realist. (shrink)

This aim of this paper is two-fold: it critically analyses and rejects accounts blending active inference as theory of mind and enactivism; and it advances an enactivist-dynamic understanding of social cognition that is compatible with active inference. While some social cognition theories seemingly take an enactive perspective on social cognition, they explain it as the attribution of mental states to other people, by assuming representational structures, in line with the classic Theory of Mind. Holding both enactivism and ToM, we argue, (...) entails contradiction and confusion due to two ToM assumptions widely known to be rejected by enactivism: that social cognition reduces to mental representation and social cognition is a hardwired contentful ‘toolkit’ or ‘starter pack’ that fuels the model-like theorising supposed in. The paper offers a positive alternative, one that avoids contradictions or confusion. After rejecting ToM-inspired theories of social cognition and clarifying the profile of social cognition under enactivism, that is without assumptions and, the last section advances an enactivist-dynamic model of cognition as dynamic, real-time, fluid, contextual social action, where we use the formalisms of dynamical systems theory to explain the origins of socio-cognitive novelty in developmental change and active inference as a tool to demonstrate social understanding as generalised synchronisation. (shrink)

This paper offers a caution that emphasis upon the importance of mathematics in recent historiography is in danger of obscuring the historical fact that, for the most part, mathematics was not seen as important in the pre-modern period. The paper proceeds by following a single case study, and in so doing offers the first account of the mathematical writings of Jean Fernel (1497–1558), better known as a leading medical innovator of the 16th century. After establishing Fernel's early commitment to mathematics, (...) and attempt to forge a career as a cosmographer, it goes on to explain his abandonment of mathematics for a career in medicine. The ‘mathematization of the world picture’ is usually explained in terms of the perceived usefulness of mathematics, but Fernel's case shows that for many pre-modern thinkers mathematics was not regarded as a useful pursuit. The paper should serve as a reminder, therefore, that the take-up of mathematics by natural philosophers was by no means inevitable, but had to be carefully managed by early modern mathematical practitioners. The case of Fernel indicates that perhaps he was not the only would-be mathematical practitioner to abandon mathematics in favour of a calling that was more appreciated by contemporaries. (shrink)

: This study of the concept of orbit is intended to throw light on the nature of revolutionary concepts in science. We observe that Kepler transformed theoretical astronomy that was understood in terms of orbs [Latin: orbes] (spherical shells to which the planets were attached) and models (called hypotheses at the time), by introducing a single term, orbit [Latin: orbita], that is, the path of a planet in space resulting from the action of physical causes expressed in laws of nature. (...) To demonstrate the claim that orbit is a revolutionary concept we pursue three lines of argument. First we trace the origin of the term; second, we document its development and specify the meaning of the novel term as it was introduced into astronomy by Kepler in his Astronomia nova (1609). Finally, in order to establish in what sense the concept is revolutionary, we pay attention to the enduring impact that the concept has had on the relevant sciences, in this case astronomy and indeed physics. We claim that orbit is an instance of a revolutionary concept whose provenance and use can provide the insights we are seeking. (shrink)

This study of the concept of orbit is intended to throw light on the nature of revolutionary concepts in science. We observe that Kepler transformed theoretical astronomy that was understood in terms of orbs [Latin: orbes] and models , by introducing a single term, orbit [Latin: orbita], that is, the path of a planet in space resulting from the action of physical causes expressed in laws of nature. To demonstrate the claim that orbit is a revolutionary concept we pursue three (...) lines of argument. First we trace the origin of the term; second, we document its development and specify the meaning of the novel term as it was introduced into astronomy by Kepler in his Astronomia nova . Finally, in order to establish in what sense the concept is revolutionary, we pay attention to the enduring impact that the concept has had on the relevant sciences, in this case astronomy and indeed physics. We claim that orbit is an instance of a revolutionary concept whose provenance and use can provide the insights we are seeking. (shrink)

ABSTRACT Throughout the early modern period, the most widely read astronomical textbooks were Johannes de Sacrobosco's De sphaera and the Theorica planetarum, ultimately in the new form introduced by Georg Peurbach. This essay argues that the images in these texts were intended to develop an “intelligent eye.” Students were trained to transform representations of specific heavenly phenomena into moving mental images of the structure of the cosmos. Only by learning the techniques of mental visualization and manipulation could the student “see” (...) in the mind's eye the structure and motions of the cosmos. While anyone could look up at the heavens, only those who had acquired the intelligent eye could comprehend the divinely created order of the universe. Further, the essay demonstrates that the visual program of the Sphaera and Theorica texts played a significant and hitherto unrecognized role in later scientific work. Copernicus, Galileo, and Kepler all utilized the same types of images in their own texts to explicate their ideas about the cosmos. (shrink)

ABSTRACT Throughout the early modern period, the most widely read astronomical textbooks were Johannes de Sacrobosco's De sphaera and the Theorica planetarum, ultimately in the new form introduced by Georg Peurbach. This essay argues that the images in these texts were intended to develop an “intelligent eye.” Students were trained to transform representations of specific heavenly phenomena into moving mental images of the structure of the cosmos. Only by learning the techniques of mental visualization and manipulation could the student “see” (...) in the mind's eye the structure and motions of the cosmos. While anyone could look up at the heavens, only those who had acquired the intelligent eye could comprehend the divinely created order of the universe. Further, the essay demonstrates that the visual program of the Sphaera and Theorica texts played a significant and hitherto unrecognized role in later scientific work. Copernicus, Galileo, and Kepler all utilized the same types of images in their own texts to explicate their ideas about the cosmos. (shrink)

I propose a new perspective on the study of scientific revolutions. This is a transformation from an object-only perspective to an ontological perspective that properly treats objects and processes as distinct kinds. I begin my analysis by identifying an object bias in the study of scientific revolutions, where it takes the form of representing scientific revolutions as changes in classification of physical objects. I further explore the origins of this object bias. Findings from developmental psychology indicate that children cannot distinguish (...) processes from objects until the age of 7, but they have already developed a core system of object knowledge as early as 4 months of age. The persistence of this core system is responsible for the object bias among mature adults, i.e., the tendency to apply knowledge of physical objects to temporal processes. In light of the distinction between physical objects and temporal processes, I redraw the picture of the Copernican revolution. Rather than seeing it as a taxonomic shift from a geocentric to a heliocentric cosmology, we should understand it as a transformation from a conceptual system that was built around an object concept to one that was built around a process concept. (shrink)

I propose a new perspective with which to understand scientific revolutions. This is a conversion from an object-only perspective to one that properly treats object and process concepts as distinct kinds. I begin with a re-examination of the Copernican revolution. Recent findings from the history of astronomy suggest that the Copernican revolution was a move from a conceptual framework built around an object concept to one built around a process concept. Drawing from studies in the cognitive sciences, I then show (...) that process concepts are independent of object concepts, grounded in specific regions of the brain and involving unique representational mechanisms. There are cognitive obstacles to the transformation from object to process concepts, and an object bias—a tendency to treat processes as objects—makes this kind of conceptual change difficult. Consequently, transformation from object to process concepts is disruptive and revolutionary. Finally, I explore the implications of this new perspective on scientific revolutions for both the history and philosophy of science.Keywords: Scientific revolutions; Process concepts; Object concepts; Object bias; Copernican revolution. (shrink)

Una manera de integrar historia y filosofía de la ciencia consiste en usar estudios históricos de caso como evidencia de conclusiones filosóficas sobre la ciencia. A pesar de tener ejemplos representativos en la actualidad, varios autores han puesto esta metodología en tela de juicio con un argumento escéptico de circularidad epistémica. En este artículo reivindico el estatus epistémico de esta metodología mediante una estrategia que muestra que este argumento no funciona o que el escéptico estaría finalmente en desventaja dialéctica. Sobre (...) esta base, señalo cómo esta controvers. (shrink)

Empiricists claim that in accepting a scientific theory one should not commit oneself to claims about things that are not observable in the sense of registering on human perceptual systems (according to Van Fraassen’s constructive empiricism) or experimental equipment (according to what I call liberal empiricism ). They also claim scientific theories should be accepted or rejected on the basis of how well they save the phenomena in the sense delivering unified descriptions of natural regularities among things that meet their (...) conditions for observability. I argue that empiricism is both unfaithful to real world scientific practice, and epistemically imprudent, if not incoherent. To illuminate scientific practice and save regularity phenomena one must commit oneself to claims about causal mechanisms that can be detected from data, but do not register directly on human perceptual systems or experimental equipment. I conclude by suggesting that empiricists should relax their standards for acceptable beliefs. (shrink)

: This paper continues my application of theories of concepts developed in cognitive psychology to clarify issues in Kuhn's mature account of scientific change. I argue that incommensurability is typically neither global nor total, and that the corresponding form of scientific change occurs incrementally. Incommensurability can now be seen as a local phenomenon restricted to particular points in a conceptual framework represented by a set of nodes. The unaffected parts in the framework constitute the basis for continued communication between the (...) communities supporting alternative structures. The importance of a node is a measure of the severity of incommensurability introduced by replacing it. Such replacements occur incrementally so that changes like that from the conceptual structure of Aristotelian celestial physics to the conceptual structure of Newtonian celestial physics occur in small stages over time, and for each change it is in principle possible to identify the arguments and evidence that led historical actors to make the revisions. Thus the process of scientific change is a rational one, even when its beginning and end points are incommensurable conceptual structures. It is also apparent, from a detailed examination of the conceptual structure of astronomy at the time of Copernicus, thatthe kind of conceptual difficulty identified as incommensurability may occur within a single scientific tradition as well as between two rival traditions. (shrink)

: This paper offers my current view of a joint research project, with Bernard R. Goldstein, that examines Kepler's unification of physics and astronomy. As an organizing theme, I describe the extent to which the work of Kepler led to the appearance of the form of Copernicanism that we accept today. In the half century before Kepler's career began, the understanding of Copernicus and his work was significantly different from the modern one. In successive sections I consider the modern conception (...) of Kepler's contribution to Copernicanism, the most influential sixteenth century view of Copernicus's work and its sequel, Kepler's work from the viewpoint of this tradition, and finally the historical origins of the modern view of Copernicanism. (shrink)