Matteo Valleriani

The Transformation of Aristotle's Mechanical Questions: A Bridge Between the Italian Renaissance Architects and Galileo's First New Science

Summary The reception process of Aristotles Mechanical Questions during the early modern period began with the publication of the corpus aristotelicum between 1495 and 1498. Between 1581 and 1627, two of the thirty-five arguments discussed in the text, namely Question XIV concerning the resistance to fracture and Question XVI concerning the deformation of objects such as timbers, became central to the work of the commentators. The commentaries of Bernardino Baldi (1581–1582), Giovanni de Benedetti (1585), Giuseppe Biancani (1615) and Giovanni di Guevara (1627) gradually approached the doctrine of proportions of the Renaissance architects, some aspects of which deal with the strength of materials according to the Vitruvian conception of scalar building. These aspects of the doctrine of proportions were integrated into the Aristotelian arguments so that a theory of linear proportionality concerned with the strength of materials could be formulated. This very first theory of strength of materials is the theory to which Galileo critically referred in his Discorsi where he published his own theory of strength of materials. Economic and military constraints are determined as the fundamental reasons for the commentators’ commitment to developing a theory of strength of materials that later linked Galileos work to the practical knowledge of the architects and machine-builders of his time.

Ancient Pneumatics Transformed during the Early Modern Period

The paper aims to show how sixteenth century hydraulic and pneumatic engineers appropriated ancient science and technology - codified in the text of Hero of Alexandria?s Pneumatics - to enter into scientific discourse, for instance, with natural philosophers. They drew on the logical structure, content and narrative style passed down from antiquity to generate and codify their own theoretical approach and to document their new technological achievements. They did so by using the form of commented and enlarged editions, just as Aristotelian natural philosophers had been doing for centuries. The argument aims to detail the exact role of ancient science and the process of transformation it underwent during the early modern period. In particular, it aims to show how pneumatic engineers first tested the ancient technology codified by Hero while carrying out their own practical activities. Once these tests were successfully concluded, in the spirit of early modern humanism they finally presented these activities as being associated with the work of their disciplines most authoritative author, Hero of Alexandria, whose technology was tested during the construction of the hydraulic and pneumatic system of the garden of Pratolino.

CorpusTracer : a CIDOC database for tracing knowledge networks

In our research, we study mechanisms of knowledge dissemination based on the structural and social networks surrounding the edition history of a single text: the Tractatus de sphaera by Johannes de Sacrobosco. By applying methods from network analysis, we investigate how specific commentaries on the text circulated, which actors were responsible for them and what factors supported or hindered the spread of specific kinds of knowledge. The basis of this investigation is represented by CorpusTracer, a database that stores the required data in a suitable format and with the required level of expressivity. In this article, we present the design of our database and our data model based on CIDOC-CRM and FRBRoo. We discuss the implementation and suitability of the conceptual and technical realization for our research question. We conclude that FRBRoo fits well to the task at hand. We found that the comparatively complex data structure it requires can be sufficiently abstracted through current implementation methods. As the research continues, our data model will have to grow and we expect that the presented methods will be sufficient to accommodate our future requirements. .................................................................................................................................................................................

The epistemology of practical knowledge

The relation between practical and theoretical knowledge, which is usually perceived as one of the motors of scientific development in the early modern period, is redefined here as the relation between different structures of knowledge, where the qualitative difference between the different structures is specified according to the degree of abstraction and the range of connections between the different fields of knowledge. The investigation begins by identifying practical knowledge and the continuous process of its reorganization into new structures. In this way, the research aims to understand how the transfer of practical activities transitioned to a circulation of practical literature and, finally, how codified practical knowledge became part of the theoretical and conceptual structures that were being established during the early modern period. As an introduction to the entire volume, a heuristic diversification of knowledge production mechanisms is defined on three levels: (1) the knowledge structure of practical activities; (2) the social structuring of practical knowledge; and (3) the conceptual structures of knowledge. The subsequent chapters are discussed and introduced according to these definitions.

The tracts on the 'Sphere' : knowledge restructured over a network

The essay focuses on the early modern tradition of commentaries on the late Medieval work of Johannes de Sacrobosco, Tractatus de sphaera. Arguing that a new knowledge system founded on the geocentric worldview emerged during the thirteenth century, the work analyzes how and why such a knowledge system changed during the early modern period in correlation with the development of practical knowledge, which emerged in the framework of the phenomenon of journeys of exploration. It is shown that new subjects were added to the original texts and finally codified and printed in the early modern editions of the text, thus creating new structures of knowledge. By applying methods derived from social network analysis, the essay finally examines how a single new subject, namely a mathematical demonstration concerning the division of the Earth’s surface into climate zones, entered the history of commentary treatises on the Sphere and how it spread over time and space by being adopted into further editions published in other places and by different printers. By means of this case study, this work concludes with the analysis of the process that leads from one abstract structure of knowledge to the next.

Was Galileo an Engineer

The most accepted view on Galileo portrays him as the great theoretician, the genius, the lone thinker who founded the modern science that changed the world dramatically through the scientific revolution. But Galileo was also an engineer, even a craftsman, who spent his life working with engineers, masters, and mathematicians. He was neither a genius nor a lonely thinker: His science is rooted in the practical knowledge of his time, and the paths of his speculations can be understood perfectly if the context of his work and of the problems considered urgently in need of a solution are taken into account.

Mental Models as Cognitive Instruments in the Transformation of Knowledge

The chapter is concerned with the epistemic structures of mechanical knowledge in its historical transformations. It describes these structures using the concept of mental models as cognitive instruments, which function as mediators between the realm of practice and experience on the one hand, and conceptual systems on the other. With the help of the concept of mental model, the chapter discusses how mechanical knowledge has emerged from experience in practical contexts and how it was transformed into theoretical and mathematically formalized knowledge systems. Focusing on one particular mental model, which describes the cognitive structure conceptualizing motion as being caused by forces, the chapter then follows its transformations in the long-term history of mechanical thinking. This so-called “motion-implies-force” model is rooted in intuitive, non-written mechanical knowledge. Over the course of history, the model was recruited, complemented, and transformed in the context of the use of mechanical tools and articulated in the work of practitioners dealing with machines, arms, ships, buildings, fortifications, and the like. Eventually, under specific cultural circumstances, this and other mental models were elaborated and integrated into mathematically formalized systems that were used, for example, in the explanation of terrestrial and celestial motions in early modern natural philosophy and the mathematical disciplines of European universities.

The Organ of the Villa d’Este in Tivoli and the Standards of Pneumatic Engineering in the Renaissance

The Villa d’Este in Tivoli near Rome was the last building project of Cardinal Ippolito II d’Este and the one that secured him lasting fame. One of its main attractions is the hydraulic organ integrated into a fountain system, called the Fountain of the Organ. This paper points to a source describing the organ’s mechanism that has been ignored until now: Oreste Vannocci Biringucci’s translation of Hero’s Pneumatics, which was commissioned in the course of building pneumatic devices in another famous villa garden, the Medici garden in Pratolino. Hero’s text is followed by a description of the technical apparatus and functioning of Tivoli’s organ, which is published and translated here for the first time. The research is based on two different descriptions of the organ of Tivoli and on a virtual reconstruction of the hydraulic organ built within the scenic reproduction of the legendary Mount Parnassus at the garden of Pratolino. By means of a comparative analysis, it will be shown that the practical experience of Renaissance pneumatic engineers is superior to the knowledge codified in the ancient texts. As a consequence, this work also shows how Renaissance gardens represented the knowledge platform for theoretical and practical knowledge.

Pneumatics, the Thermoscope and the New Atomistic Conception of Heat

In Galileo’s day, once important scientific questions had been formulated, they often found wide circulation by means of letters or notes sent to friends and acquaintances. Today’s name for one such scientific problem is “Bardi’s problem,” for the question had been presented to Galileo by Count Bardi di Vernio (1534–1612).1. The problem, and even more so its solution, represent a paradigmatic logical model for the period before instruments had been invented to measure temperature. The problem suggests investigating why a person feels cold when he goes into a body of water like a river during the summer, and even colder when he comes out, but, going back into the water, finally feels comfortable. There were several variations of this problem after his first formulation. For example, the condition was often added that, before the person goes bathing, he spends time in the shade where he feels neither cold nor hot and, when he comes out of the water, he returns to this shady location.2.

Instruments and Machines

Galileo’s apprenticeship allowed him to build bridges to mathematicians, philosophers and several kinds of artist-engineers and craftsmen, including mirror makers, military engineers, and machine builders. In the context of such a network, Galileo cultivated and practiced all of these activities himself. He opened his own workshop in Padova, which produced mathematical instruments for military officers; starting in 1610, upon his move to Florence in the service of the Grand Duke, he made optical instruments destined primarily for military use; and over the course of his life he became a recognized expert on machines, especially on those devices useful for living and fighting within fortresses.