Integrating social, political, and intellectual history, her dissertation, “Nature, Self, and History in the Works of Andrea Alciati [1492-1550], Guillaume Budé [1467-1540] and Ulrich Zasius [1461-1536]: A Study of the Role of Legal Humanism in Western Natural Law,” explored how the introduction of philological, comparative, and historical methods to the teaching and interpretation of Roman law informed the centrality of ius gentium (universal customary law or the laws of peoples) within natural law and natural rights theories from the sixteenth century onwards. By focusing on lectures, treatises, orations and emblems, she demonstrated how the humanists used the category of ius gentium—which they held was the source of the rights of individuals—to hold civil laws, and those who administered them, accountable to a higher criterion of justice.
Karr is currently in the process of transforming her dissertation into a book tentatively entitled On Justice and Right: The Moral Authority of Jus Gentium, which will expand the project beyond the French, German, and Italian contexts. To do so, she will explore the works of an early sixteenth-century humanist Christopher St. Germain (1440-1540) and expand the manuscript to include the next generation of humanist jurists including Jacques Cujas (1520-1590), Hugo Donellus (1527-1591) and Mathew Wesenbeck (1531-1586). As professors and lawyers, each had a substantial impact on the continuing development of European political thought and practice in the sixteenth century, especially in relation to their interpretations of ius and ius gentium and the limits each imposed on sovereign authorities. Finally, they each, in different ways, directly influenced the so-called fathers of international law: Alberico Gentili (1552-1608) and Hugo Grotius (1583-1645).
Her broader teaching and research interests include: Humanism, the Renaissance, the Reformation, European Legal History, early-modern state formation, and European expansion in comparative perspective. She is also prepared to teach survey courses, such as Western Civilization and/or World History from antiquity through the eighteenth century, and specialized courses on the rights of war and peace, the development of international law, the history and theory of human rights and humanitarianism, and historical methodology.