Introduction A new disciplinary awareness in astronomy arose in the late sixteenth century. In the centuries before the publication of Nicolaus Copernicus’ (1473-1543) De revolutionibus orbium coelestium in 1543, natural philosophy and mathematics were considered separate university subjects with relatively no overlap. Natural philosophy was the search for either physical or natural causes, whereas mathematics “sought demonstrations based only on the formal properties of magnitudes. The two domains related to radically different kinds of questions about the world.”1 The disciplinary boundaries that existed between the two were so entrenched among scholars that challenges to these boundaries persisted well into the seventeenth century. Moreover, natural philosophy was clearly more prominent and important than mathematics, as the latter was rarely emphasized in the universities. The publication of Copernicus’ De revolutionibus helped create a disciplinary awareness in astronomy. Beginning in this period, the role of the astronomer became much less “fixed” and “static,” and became more of a “dynamic, evolving, ‘negotiated’ process. .”2 Astronomy steadily became a study to be pursued independently and with a renewed vigor that was unparalleled in previous centuries. The emergence of this disciplinary consciousness was furthered by printers who published astronomical treatises by individuals from different parts of Europe and even from different confessions.3 In order to comprehend this new awareness in disciplinary astronomy in its fullest context, it is first necessary to briefly describe the relations between natural philosophy and astronomy and the views of three key figures in this period – 1 Peter Dear, Discipline & Experience: The Mathematical Way in the Scientific Revolution (Chicago: The University of Chicago Press, 1995), 167. Dear provides a detailed explanation of the boundaries and relations between natural philosophy and mathematics in Chapter 6, “Art, Nature, Metaphor: The Growth of Physico- Mathematics” (Ibid., 151-179). 2 Robert S. Westman, “The Astronomer’s Role in the Sixteenth Century,” History of Science 18 (1980): 106. 3 Westman, “The Astronomer’s Role,” 105. 1 Tycho Brahe (1546-1601), Johannes Kepler (1571-1630), and Galileo Galilei (1564-1642) – towards that relationship. The Emergence of Astronomy as a Discipline from the Late Sixteenth to Early Seventeenth Centuries Copernicus was perhaps the first individual to make a contribution to disciplinary changes in astronomy. He managed to open new doors in the field with the publication of a single work. However, it took nearly a century for Copernicus’ heliocentric system as proposed in his De revolutionibus to become widely accepted. In fact, by 1600, when Copernicanism was about sixty years old, only a handful of individuals accepted it.4 Aristotelian cosmology coupled with Ptolemaic astronomy remained the dominant and accepted system of the heavens. In the late sixteenth and early seventeenth centuries, the most noteworthy system was the Tychonic system that excluded both the redundancy and awkwardness of Ptolemy’s system while at the same time avoiding Copernicus’ heliocentrism. There were also other acceptable systems among astronomical practitioners and mathematicians such as the system found in Thomas Lydiat’s (1572-1646) Praelectio Astronomica, De Natura Coeli (1605) in which he proposed a system that was neither Tychonic nor Copernican. Lydiat’s model even resembled Girolamo Fracastoro’s (c. 1478-1553) system of homocentric spheres found in his Homocentrica (1538).5 Tycho’s “compromise” between the two systems of Ptolemy and Copernicus rivaled Copernicus’ own system until the middle of the seventeenth century when the Copernican system became dominant as indicated by the large number of heliocentric treatises produced at the time.6 The victory of the Copernican system over all others was eventually “achieved by infiltration,”7 largely facilitated by the handful of Copernicans in the fifty or so years after the publication of De revolutionibus. These included George Joachim Rheticus (1514-1574), Thomas Digges (c. 1543-1595), Michael Maestlin (1550-1631) and even Erasmus Reinhold (1511-1553), who although not a declared Copernican, published his own work using 4 See Westman, “The Astronomer’s Role,” 136 n. 6, for a list of known Copernicans in this period. 5 Francis R. Johnson, Astronomical Thought in Renaissance England: A Study of the English Scientific Writings from 1500 to 1645 (New York: Octagon Books, Inc., 1968), 321. 6 Johnson, Astronomical Thought in Renaissance England, 249. 2 Copernicus’ mathematical methods.8 Naturally, the impact of telescopic discoveries in the beginning of the seventeenth century should not be overlooked, as they too contributed to the eventual overthrow of the more traditional systems by confirming the veracity of heliocentrism. Changes in the intellectual and social roles of the astronomer were encouraged by Copernicus’ implicit assertion that an astronomer has the “right” to propose “new kinds of claims about the physical world.” In disciplinary terms: an argument from geometry together with certain privileged observations is taken to be sufficient” for redefining reality, although this was not palatable to natural philosophers who questioned the validity of the senses that had been a part of natural philosophy for centuries.9 Copernicus’ views in his De revolutionibus did not agree with the preface written by Andreas Osiander (1498-1552) in which Osiander claimed that the duty of an astronomer [is] to compose the history of the celestial motions through careful and expert study. Then he must conceive and devise the causes of these motions or hypotheses about them. Since he cannot in any way attain to the true causes, he will adopt whatever suppositions enable the motions to be computed correctly from the principles of geometry for the future as well as for the past. For these hypotheses need not be true nor even probable.10 The astronomer’s role was to study celestial motions through the use of geometry, but because he could never know “true causes,” he had to satisfy himself with suppositions and hypotheses, and make way for the domain of natural philosophers. Osiander’s preface was not enough to stem the impact of Copernicus’ work, however. Copernicus’ innovation, which managed to “bridge disciplines,” led to the negotiation of “the rules governing disciplinary behaviour.”11 At the time that Copernicus’ system was slowly “infiltrating” European astronomy, Jesuit colleges were on the rise throughout Catholic territories. Viewed as among the most important institutions of the early modern period, Jesuit colleges promoted the mathematical disciplines that, by the beginning of the seventeenth century, “had come to hold a comparatively prominent place in the courses of study offered by the Jesuits. .”12 At the Collegio Romano, Christopher Clavius (1537-1612), the professor of mathematics from 1565 to 1612, was instrumental in 7 Thomas S. Kuhn, The Copernican Revolution (Cambridge, MA: Harvard University Press, 1957), 185. 8 Kuhn, The Copernican Revolution, 187. 9 Westman, “The Astronomer’s Role,” 111. 10 Osiander’s “Anonymous” preface in John G. Burke, ed., Science and Culture in the Western Tradition (Scottsdale, Arizona: Gorsuch Scarisbrick, Publishers, 1987), 95. In this translation, the word “hypothesis” appears eight times. 11 Westman, “The Astronomer’s Role,” 134. These “rules” are discussed in later chapters. 3 promoting mathematics in the curriculum and elevating its status by arguing for its certainty in demonstrations. Despite the efforts of individuals such as Clavius, one finds that nowhere in the mid-to- late sixteenth century were there opportunities to obtain an advanced degree in astronomy or mathematics: “no licensing, that is, which recognized that symbol of full disciplinary autonomy.”13 The graduate faculties of law, theology, and medicine dominated the universities of this period. Astronomy was still part of the quadrivium along with geometry, arithmetic, and musical theory. Mathematics, in general, existed as a “service role” for other fields, and any improvements in astronomy, which was practiced for certain consumer groups, usually meant the extent to which astronomy made practical contributions such as better astrological predictions and improved calendars. One does not see the academic as a researcher in problems concerning “cosmology and theoretical astronomy; it was largely a pedagogical position for an undergraduate subject.”14 The lack of professionalization in astronomy may not appear to have been a serious problem, but the lack of a formalized discipline in general is significant. First, the subject is not perceived as important or necessary within the larger framework of university curricula, and is therefore subordinated to other subjects. This makes it challenging to attract students and promote the subject. Also, without formalized instruction, it is difficult to establish a common base with which to link people together into a community that makes it harder to collaborate. For those interested in the pursuit of astronomy, some of these points might have presented themselves as problems for astronomers in the late sixteenth and early seventeenth centuries. Nevertheless, certain individuals were able to rise above these obstacles and find ways of both acquiring an education in mathematical studies and find others who were willing to collaborate with them. The English universities,