Astrology is a science which has had an uncertain status throughout its history, from its beginnings in Greco-Roman Antiquity to the medieval Islamic world and Christian Europe which led to frequent debates about its validity and what kind of a place it should have, if any, in various cultures. Written in the second century A.D., Ptolemy’s Tetrabiblos is not the earliest surviving text on astrology. However, the complex defense given in the Tetrabiblos will be treated as an important starting point because it changed the way astrology would be justified in Christian and Muslim works and the influence Ptolemy’s presentation had on later works represents a continuation of the method introduced in the Tetrabiblos. Abū Ma‘shar’s Kitāb al-Madkhal al-kabīr ilā ‘ilm akām al-nujūm, written in the ninth century, was the most thorough surviving defense from the Islamic world. Roger Bacon’s Opus maius, although not focused solely on advocating astrology, nevertheless, does contain a significant defense which has definite links to the works of both Abū Ma‘shar and Ptolemy. As such, he demonstrates another stage in the development of astrology. These three works together reveal the threads of a trend of a rationalized astrology separated from its mythical origins which began with Ptolemy and survived through both medieval Islam and medieval Europe. In the two examples of defending astrology I have used, Abū Ma‘shar and Roger Bacon, Ptolemy’s influence can be seen to have persisted from the second century through to the thirteenth, and the nature of the differences in their defenses illustrates the continuation and evolution of the tradition of defending astrology.

Following Merton (1942) science studies has moved from the philosophy of science to a more sociologically minded analysis of scientific activity. This largely involves a shift away from questions that bear on the context of justification – a question of rationality and philosophy, to those that deal with the context of discovery. This thesis investigates changes in science studies in three papers: sociocultural evolutionary theories of scientific change; general trends in science studies - especially concerning the sociology of science; and a principle component analysis (PCA) that details the development and interaction between research programmes in science studies. This thesis describes the proliferation of research programmes in science studies and uses evolutionary theory to make sense of the pattern of change.

Master of Arts / Department of Economics / Lance J. Bachmeier / This thesis examines the properties of two short-term interest rates: the federal funds rate and the rate of return on 90-day Treasury securities (T-Bills). Findings indicate strong evidence of cointegration among the two series. This result leads us to consider whether future movements in T-bill returns are predictable using the same methods used to predict the target federal funds rate. The “Taylor Rule,” introduced by Taylor (1993), assumes the Federal Reserve considers inflation and the output gap in their deliberation of how to adjust the federal funds target rate. We do an in-sample analysis followed by an out-of-sample forecasting comparison. Findings show that, in addition to inflation and the output gap, the unemployment rate and stock market contain valuable information for forecasting future T-bill rates.

Through the development of physical chemistry and chemical physics over the late-nineteenth and early-twentieth centuries, the relationship between physics and chemistry changed to create a broad interdisciplinary framework in which chemists and physicists could make contributions to problems of common value. It is here argued that evolving disciplinary factors such as physical and chemical responses to the atomic hypothesis, the nature of disciplinary formation in Germany and the United States, the reception of quantum mechanics within physics and chemistry, and the application of quantum mechanics to the problem of chemical bonding by physicists and chemists, formed the chemical bond into a physico-chemical theory. In the late nineteenth-century context of early physical chemistry, the chemical bond was known as a physical link between atoms, which could not be studied by chemical means because of the lack of an adequate atomistic framework. Both chemists and physicists broadly accepted the atomistic hypothesis following the discovery of the electron at the turn of the twentieth century, which afforded theoretical study of chemical bonding. Between 1916 and 1919, Gilbert N. Lewis and Irving Langmuir proposed the valence bond to be a pair of electrons shared between two atoms, within the context of a cubic model of the atom. However, the lack of a physical mechanism for the shared electron pair prevented the formation of a fully physico-chemical view of bonding. In 1927, physicists Walter Heitler and Fritz London showed the stability of the valence bond was caused by the wave mechanical phenomenon of resonance. Chemist Linus Pauling extended their treatment of the valence bond to a theory of structural chemistry in The Nature of the Chemical Bond. His synthesis of the physical and chemical views, his value as a physico-chemical researcher during the 1930s, and the research of his contemporaries John Slater and Robert Mulliken show that a true physico-chemical blend was only realized within the amorphous discipline of chemical physics. Finally, it is seen that this interdisciplinarity of chemical bonding and its supporting framework force a reevaluation of the reductionist criteria, and a re-definition of the chemical bond as a physico-chemical work.

Gaslight, an Industrial Revolution technology, developed in the period 1780–1820. The foundations for the technology are partly found in the pneumatic chemistry of the eighteenth century, both in terms of the knowledge of gases and their properties, and the instruments used to manipulate them, such as the gasometer, making gaslight one of the earliest instances of a technology heavily based on science. Although many people experimented with lighting with gases in the late eighteenth century, the move to a commercial technology began with Philippe Lebon and William Murdock who had a clear commercial purpose in mind. The technology in its early phases was found everywhere in Europe, but it was at Boulton & Watt in Birmingham that it was first successfully applied. As Boulton & Watt developed the technology they identified many and solved some of the problems associated with scaling up the technology. They were not, however, very interested in gaslight and only sporadically gave attention to it, before effectively abandoning it around 1812. They nevertheless had an important role to play in its development not only because if their technical work, but also because they demonstrated the technology’s viability to the broad public, and by giving people experience in gas engineering. The technology's final form as a network utility was partly as a result of a battle fought between Boulton & Watt and Frederick Winsor's Gas Light and Coke Company in London during 1807–1810. Boutlon & Watt did not want a large limited-liability corporation as a competitor, and the contest in Parliament between the two groups resulted in a negotiated compromise where the Gas Light and Coke Company gave up all rights to manufacture apparatus, and focused exclusively on gas provision, effectively making it a utility. The years from 1812–1820 saw the technology mature into a large network which included not only technical development, such as the pressure balancing with valves and regulators, but also political and social elements, such as the control of user expectations through education and usage enforcement through inspectors. By 1820, the technology was sufficiently developed to be transferred to the Continent.

Through the development of physical chemistry and chemical physics over the late-nineteenth and early-twentieth centuries, the relationship between physics and chemistry changed to create a broad interdisciplinary framework in which chemists and physicists could make contributions to problems of common value. It is here argued that evolving disciplinary factors such as physical and chemical responses to the atomic hypothesis, the nature of disciplinary formation in Germany and the United States, the reception of quantum mechanics within physics and chemistry, and the application of quantum mechanics to the problem of chemical bonding by physicists and chemists, formed the chemical bond into a physico-chemical theory. In the late nineteenth-century context of early physical chemistry, the chemical bond was known as a physical link between atoms, which could not be studied by chemical means because of the lack of an adequate atomistic framework. Both chemists and physicists broadly accepted the atomistic hypothesis following the discovery of the electron at the turn of the twentieth century, which afforded theoretical study of chemical bonding. Between 1916 and 1919, Gilbert N. Lewis and Irving Langmuir proposed the valence bond to be a pair of electrons shared between two atoms, within the context of a cubic model of the atom. However, the lack of a physical mechanism for the shared electron pair prevented the formation of a fully physico-chemical view of bonding. In 1927, physicists Walter Heitler and Fritz London showed the stability of the valence bond was caused by the wave mechanical phenomenon of resonance. Chemist Linus Pauling extended their treatment of the valence bond to a theory of structural chemistry in The Nature of the Chemical Bond. His synthesis of the physical and chemical views, his value as a physico-chemical researcher during the 1930s, and the research of his contemporaries John Slater and Robert Mulliken show that a true physico-chemical blend was only realized within the amorphous discipline of chemical physics. Finally, it is seen that this interdisciplinarity of chemical bonding and its supporting framework force a reevaluation of the reductionist criteria, and a re-definition of the chemical bond as a physico-chemical work.

Gaslight, an Industrial Revolution technology, developed in the period 1780–1820. The foundations for the technology are partly found in the pneumatic chemistry of the eighteenth century, both in terms of the knowledge of gases and their properties, and the instruments used to manipulate them, such as the gasometer, making gaslight one of the earliest instances of a technology heavily based on science. Although many people experimented with lighting with gases in the late eighteenth century, the move to a commercial technology began with Philippe Lebon and William Murdock who had a clear commercial purpose in mind. The technology in its early phases was found everywhere in Europe, but it was at Boulton & Watt in Birmingham that it was first successfully applied. As Boulton & Watt developed the technology they identified many and solved some of the problems associated with scaling up the technology. They were not, however, very interested in gaslight and only sporadically gave attention to it, before effectively abandoning it around 1812. They nevertheless had an important role to play in its development not only because if their technical work, but also because they demonstrated the technology’s viability to the broad public, and by giving people experience in gas engineering. The technology's final form as a network utility was partly as a result of a battle fought between Boulton & Watt and Frederick Winsor's Gas Light and Coke Company in London during 1807–1810. Boutlon & Watt did not want a large limited-liability corporation as a competitor, and the contest in Parliament between the two groups resulted in a negotiated compromise where the Gas Light and Coke Company gave up all rights to manufacture apparatus, and focused exclusively on gas provision, effectively making it a utility. The years from 1812–1820 saw the technology mature into a large network which included not only technical development, such as the pressure balancing with valves and regulators, but also political and social elements, such as the control of user expectations through education and usage enforcement through inspectors. By 1820, the technology was sufficiently developed to be transferred to the Continent.

In virtue of what do scientific diagrams acquire their epistemic legitimacy? Which factors serve to validate schematic visual representations, rendering them useful and accepted components of scientific practice? This thesis addresses the epistemic legitimacy of scientific diagrams by investigating a variety of diagrams whose referents are “invisible”, that is, whose targets either cannot be seen, lack physical form, or have no material analogue. In focusing on such images, we shall gain insight into the factors that shape the forms that practicing scientists give to their diagrams and shed light on contemporary issues in the philosophy of scientific models and representations. In this work, common factors underscoring the epistemic legitimacy of scientific diagrams are identified through three in-depth historical case studies. First, we consider several diagrammatic approaches to visualizing chemical structure that emerged around the 1860s, especially the competing approaches of August Kekulé and Alexander Crum Brown, and investigate the factors that led to the enduring success of Crum Brown’s visual representations and the corresponding abandonment of Kekulé’s. Second, we examine a spectrum of stereochemical diagrams and material models produced from the 1870s to the early 20th century, particularly those produced by J. H. van ‘t Hoff, and consider the factors that determined the forms given to representations of three-dimensional structures of chemical compounds. Third, we explore the diagrammatic approaches taken by physicist Richard Feynman in his mid-20th century lectures on quantum electrodynamics, paying close attention to his diagrams’ stylistic commonalities and dissimilarities as well as their ability to mediate between various aspects of the practice of physics. Finally, this thesis concludes by considering several common factors regarding the epistemic legitimacy of scientific diagrams that can be identified in these case studies, including the importance of a bijective relationship between scientists’ understanding of their diagrams and of their diagrams’ referents, the utility of diagrams for productively reasoning about their referents, and ability of certain diagrams to reduce scientists’ cognitive burden, especially through visual similarities. These factors serve to unite divergent approaches to the philosophy of scientific models and representation and reorient contemporary debates concerning representation towards an integrated historical-philosophical methodology.

In virtue of what do scientific diagrams acquire their epistemic legitimacy? Which factors serve to validate schematic visual representations, rendering them useful and accepted components of scientific practice? This thesis addresses the epistemic legitimacy of scientific diagrams by investigating a variety of diagrams whose referents are “invisible”, that is, whose targets either cannot be seen, lack physical form, or have no material analogue. In focusing on such images, we shall gain insight into the factors that shape the forms that practicing scientists give to their diagrams and shed light on contemporary issues in the philosophy of scientific models and representations. In this work, common factors underscoring the epistemic legitimacy of scientific diagrams are identified through three in-depth historical case studies. First, we consider several diagrammatic approaches to visualizing chemical structure that emerged around the 1860s, especially the competing approaches of August Kekulé and Alexander Crum Brown, and investigate the factors that led to the enduring success of Crum Brown’s visual representations and the corresponding abandonment of Kekulé’s. Second, we examine a spectrum of stereochemical diagrams and material models produced from the 1870s to the early 20th century, particularly those produced by J. H. van ‘t Hoff, and consider the factors that determined the forms given to representations of three-dimensional structures of chemical compounds. Third, we explore the diagrammatic approaches taken by physicist Richard Feynman in his mid-20th century lectures on quantum electrodynamics, paying close attention to his diagrams’ stylistic commonalities and dissimilarities as well as their ability to mediate between various aspects of the practice of physics. Finally, this thesis concludes by considering several common factors regarding the epistemic legitimacy of scientific diagrams that can be identified in these case studies, including the importance of a bijective relationship between scientists’ understanding of their diagrams and of their diagrams’ referents, the utility of diagrams for productively reasoning about their referents, and ability of certain diagrams to reduce scientists’ cognitive burden, especially through visual similarities. These factors serve to unite divergent approaches to the philosophy of scientific models and representation and reorient contemporary debates concerning representation towards an integrated historical-philosophical methodology.

Les débats économiques au 19e siècle, loin d’être l’apanage du monde universitaire, étaient aux États-Unis un des principaux objets de contentieux entre les partis politiques et ceux-ci trouvaient écho dans la sphère publique. Les journaux étaient alors le principal moyen de communiquer les opinions des différents partis. La présente étude vise à mettre en contexte et cerner la position des écrits du plus important économiste américain de son époque, Henry Charles Carey (1793-1879), reconnu comme tel par J.S. Mill et Karl Marx en leur temps, lors de la décennie de 1850 dans le journal le plus influent de cette période, le New York Tribune. Pour ce faire, il a fallu au préalable identifier les articles non signés de Carey dans le journal, ce qui n’avait auparavant jamais été fait. Au moment d’écrire dans le principal organe américain qui défendait la protection aux États-Unis afin d’industrialiser le pays, Carey était alors le représentant le plus prééminent du système américain d’économie. Ce dernier, fondé sur les écrits d’Alexander Hamilton, prônait l’industrialisation des États-Unis et l’intervention de l’État pour défendre le bien commun, s’opposant ainsi à l’école libérale anglaise basée sur les écrits d’Adam Smith. Conceptuellement, la pensée économique de Carey se situe dans la tradition des Autres Canon, basée sur la production et l’innovation. Ceci le mena à s’opposer avec vigueur tant au malthusianisme qu’à la division internationale du travail, justifiée théoriquement par la thèse de l’avantage comparatif de Ricardo. En effet, dans son analyse, la volonté exprimée au milieu du 19e siècle par l’Angleterre de devenir l’atelier du monde et de faire du reste des nations des producteurs de matières premières sous un régime de libre-échange n’était rien d’autre que la continuation de la politique coloniale par d’autres moyens. Pour Carey, la spécialisation dans l’exportation de matières premières, notamment défendue par les planteurs du Sud des États-Unis, loin d’être bénéfique au pays, était le sûr gage de la pauvreté comme les cas de l’Irlande et de l’Inde le démontraient. / During the19th century in the United States, economic debates, far from being limited to the academic world, were one of the main subjects of dispute among political parties, finding echo in the public sphere. At the time, newspapers were the primary way of circulating the opinions of the different political parties. The aim of the present study is to contextualize and understand the writings of Henry Charles Carey (1793-1879), the most important American economist of his age, recognized as such by J.S. Mill and Karl Marx, during the 1850s in the most influential newspaper of that period, the New York Tribune. To do so, it was first necessary to locate the unsigned articles written by Carey in this newspaper; something which to date had never been done. At the time that Carey wrote in this paper, the main American organ defending protection so as to industrialize the country, he was the most eminent representative of the American System of economy. Founded on the writings of Alexander Hamilton, it advocated industrialization and defend the role of the state to promote the general welfare and was thus opposed to the English liberal school based on Adam Smith’s writings. Conceptually, Carey’s economic thought followed the tradition of the Other Canon, based on production and innovation. This led him to vigorously oppose Malthusianism and the international division of labor, theoretically justified by Ricardo’s thesis of comparative advantage. Indeed, in his analysis, England’s desire to become the workshop of the world in the mid-19th century and to transform the rest of the world into producers of raw materials under a free-trade regime, was nothing more than the continuation of colonial policy by other means. For Carey, specialization in raw materials exports, notably supported by the southern planters in the United States, far from been beneficial to the country, was the surest path to poverty as demonstrated by the Irish and Indian cases.