“This book fills an important gap in our understanding of early modern causation and occasionalism. Henkel’s clear and authoritative work will serve as an essential guide to those interested in the tradition of occasionalism as it evolved in the important era from Leibniz to Kant.”
Jeffrey K. McDonough, Harvard University, USA
“For a long time, early modern Germany remained a foggy land. Only a few towering peaks—Leibniz, Wolff, Kant—could be discerned. Today, new light is lifting the fog and we are discovering a much more complex and diverse landscape. By drawing attention to the vibrancy of early modern German debates about causation and the spread of occasionalism, Henkel's book contributes to this change of perspective. It is an exciting story that has been waiting to be told.”
Andrea Sangiacomo, Groningen University, The Netherlands
"In presenting a nuanced picture of German occasionalism and discussing authors who are often neglected, Henkel does not only make an important contribution to the study of theories of causation. He also sheds new light on the development of German philosophy in the early modern period. There is no straight path that leads from Leibniz to Wolff and Baumgarten and finally to Kant, as is often suggested in handbooks. It is important to take a close look at Leibniz’s opponents (as well as his reaction to them, of course) to understand how and why causation became a hotly debated topic in early modern Germany. Henkel’s study, which combines careful historical work with sharp philosophical analysis, is an excellent starting point" (Journal of the History of Philosophy, 63.3 (2025): 489).
Dominik Perler, Humboldt Universität zu Berlin, Germany
Dominik Perler’s complete review of my book in the Journal of the History of Philosophy, 63.3 (2025), pp. 488-489 can be found here.
Occasionalism ad the Debate about Causation in Early Modern Germany
(Routledge, 2024)
This is the first book to focus on occasionalism in early modern German philosophy. It demonstrates that occasionalism provided a strong foundation for the thought of four important yet underexamined German philosophers: Erhard Weigel, Johann Christoph Sturm, Christian Wolff, and Gottfried Ploucquet.
Occasionalism is most often associated with Cartesian early modern Christian philosophers, the most famous of whom is perhaps Nicolas Malebranche. Early modern German occasionalism has received very little scholarly attention, leaving us with an incomplete picture of the German causation debate from Leibniz to Kant. This book combines a chronological investigation of four influential and historically connected cases of occasionalism in early modern Germany with a reconstruction of arguments to address specific problems in metaphysics, natural philosophy, philosophy of language, and philosophy of psychology. Providing a sufficient ground for nature and human beings’ mental and physical existence is a pressing issue for Weigel, Sturm, Wolff, and Ploucquet. In examining the thought of these four understudied German philosophers, this book helps us rethink the relation between metaphysics of nature and science of nature and better understand the development of early modern debates about causation.
Occasionalism and the Debate about Causation in Early Modern Germany is an important resource for scholars and advanced students working on the history of early modern philosophy and the history of metaphysics and causation.
Table of Contents
Introduction
1. Erhard Weigel. Continuous Creation, Discontinuous Time, and Occasionalism
2. Johann Christoph Sturm. Mechanism, Occasionalism, and Final Causes
3. Christian Wolff. Mind-body Interaction, Language, and Occasionalism
4. Gottfried Ploucquet. Occasionalism and the Grounding of Sense-Perception
Conclusion
Appendix: Biographical Sketches
ISBN 9781032710419
202 Pages
My book can be purchased here.
Peer-reviewed Research Articles
(1) “Johann Christoph Sturm’s Opposition to Cartesianism.” Intellectual History Review, 2026. Forthcoming. DOI: 10.1080/17496977.2026.2667700
(2) “Nec contra rationem nec supra rationem. Du Châtelet’s Critical Approach to Faith and to Reading the Bible,” collected volume on Early Modern Women: Religious Innovation and the Development of the European Enlightenment, edited by Katherine O’Donnell and Francesco Quatrini, 203–221. London: Bloomsbury, 2026.
(3) “Krise und Reform der Metaphysik im frühneuzeitlichen Deutschland,” (“Crisis and Reform of Metaphysics in Early Modern Germany”), Bildbruch, vol. 7 (2025), pp. 167–184.
(4) “The Need for Reform in Early Modern German Metaphysics and the Impact of the Scientific Societies.” Perspectives on Science, vol. 33, no. 5 (2025), pp. 579–604.
(5) “Political Theory among Cartesians: Cordemoy and Le Grand.” History of European Ideas, vol. 51, issue 8 (2025), pp. 1795–1813.
(6) “Sturm’s Eclectic Scientific Method and his Indebtedness to Bacon.” The British Journal for the History of Science, vol. 59, no. 1 (2026), pp. 97–113
(7) “Sturm’s Mechanist Account of Plant Life.” Nuncius, 2025. DOI: 10.1163/18253911-bja10142:
(8) “Physical Influx Theory: The Case of Émilie du Châtelet.” The British Journal for the History of Philosophy, Vol. 33.3 (2025), pp. 562–583.
(9) “Mind-to-mind Communication and the Case of Inter-mental Occasionalism.” Res philosophica, Vol. 101.3 (2024), pp. 459–478.
(10) “The Young Leibniz’s Tentative Acceptance of Physical Occasionalism.” The Southern Journal of Philosophy, vol. 62. 4 (2024), pp. 486–500.
(11) “The last of his kind? Gottfried Ploucquet’s occasionalism and the grounding of sense-perception,” British Journal for the History of Philosophy, Vol. 30.6 (2022), pp. 1055–1073.
(12) “Mechanism, Occasionalism and Final Causes in Johann Christoph Sturm’s Physics,” Early Science and Medicine, Vol. 26.4 (2021), pp. 314–340
(13) “Johann Christoph Sturm,” in The Stanford Encyclopedia of Philosophy (online); Andrea Sangiacomo (co-author). https://plato.stanford.edu/entries/johann-sturm/, 2020/2024
(14) Reply to Matteo Favaretti’s CRITICAL NOTICE “Causal Powers in the German Ramifications of Occasionalism,” International Journal of Philosophical Studies, vol. 33, no. 3 (2025): 358–361. DOI: 10.1080/09672559.2025.2580811
Pages from Sturm's physics lectures.
Archival research on Johann Christoph Sturm's natural philosophy in the City Library in Nuremberg.
“Matteo Favaretti Camposampiero, Emanuela Scribano, Mariangela Priarolo (eds.): Occasionalism. From Metaphysics to Science; Society and Politics, Vol. 13, No. 2 (26) (November 2019) (book review), pp. 114–117
“Steven Nadler: The Good Cartesian: Louis de la Forge and the Rise of a Philosophical Paradigm”. The Journal of the History of Philosophy. Forthcoming.
“Jeffrey McDonough and Clara Carus (eds.): Émilie Du Châtelet in Relation to Leibniz and Wolff, The Journal of the History of Philosophy. Forthcoming.