THIS BOOK began as an attempt to understand how it could be that the person who wrote the Mysterium cosmographicum could also be the same who wrote the Astronomia nova. John Thorp and William Harper pointed me in the direction of this problem, which became the primary theme of my doctoral dissertation at the University of Western Ontario. William Harper, my dissertation supervisor, guided my efforts with grace and seemingly infinite patience. William's constructive criticisms, emotional support, and generosity with his time, were the sine qua non of this book, and I am lucky to have worked with him. I am grateful to John Thorp for his tutelage in matters of ancient Greek music theory and Latin, and his support of my project. Howard Plotkin offered an excellent critique of my dissertation, and chapter 4 in particular benefited enormously from his efforts. Owen Gingerich was the external examiner for my dissertation, and I am thankful for his support and direction.
I addressed the business of turning my thesis into a book while on an Postdoctoral Fellowship at the University of Chicago. I owe a tremendous debt of gratitude to Noel Swerdlow, whose patronage and advice have been invaluable. Noel was extremely giving not only of his expertise in the history of astronomy, but also his time and marvelous sense of humour. Writing a book taxes both time and spirit, and Noel's support made the latter a renewable resource. Noel also generously offered the wonderful diagrams shown in figures 1.2–1.9, 2.1, 3.1, 3.2, 4.1–4.3, 4.5, 4.7–4.10, 7.1–7.3.
Various sections of this book were read at conferences and colloquia and discussed with friends, and I have received valuable feedback. In particular, I thank Nicholas Jardine, Howard Stein, Dan Garber, David Millar, Elaine Landry, Eric Schliesser, Erik Curiel, Steven Secker, Tim Kenyon, Bryce Bennett, William Vanderburgh, and Fransisco Flores. James Voelkel has been very generous with the results of his excellent study of the Kepler-Fabricius correspondence.
Last, but definitely not least, I owe much to Jason Holt. Not only has he been extremely supportive of this project from start to finish, but he spent countless hours poring over various drafts of this book and copyediting the penultimate version. Any elegant turns of phrase are his doing, and the final product has been improved immeasurably by his efforts. I dedicate this book to him and to my parents, John and Hedy Martens.