The long period from the Renaissance to the nineteenth century supplied numerous sources for Kierkegaard's thought in any number of different fields. The present, rather heterogeneous volume covers the long period from the birth of Savonarola in 1452 through the beginning of the nineteenth century and into Kierkegaard's own time. The Danish thinker read authors representing vastly different traditions and time periods. Moreover, he also read a diverse range of genres. His interests concerned not just philosophy, theology and literature but also drama and music. The present volume consists of three tomes that are intended to cover Kierkegaard's sources in these different fields of thought. Tome I is dedicated to the philosophers of the early modern period and the Enlightenment who played a role in shaping Kierkegaard's intellectual development. He was widely read in German and French philosophy of the sixteenth, seventeenth and eighteenth centuries, making reference to the leading rationalist philosophers Descartes, Spinoza and Leibniz in his journals and published works. Further, connections have also been pointed out between his thought and the writings of the French thinkers Montaigne, Pascal and Rousseau, who share with Kierkegaard a form of philosophy that is more interested in life and existence than purely conceptual analysis. Through the works of the authors explored here Kierkegaard became acquainted with some of the major philosophical discussions of the modern era such as the beginning of philosophy, the role of doubt, the status of autonomy in ethics and religion, human freedom, the problem of the theodicy found in thinkers such as Bayle and Leibniz, and the problem of the relation of philosophy to religion as it appears in the German writers Jacobi and Lessing.