Kant's Pre-Critical Thought Experiments and the Vis Viva Controversy

This article investigates the role played by thought experiments in Kant's evaluation of the vis viva controversy. The vis viva debate revolved around differing conceptions of force, with the Cartesian tradition interpreting force quantitatively as momentum, while Leibnizians viewed it qualitatively as kinetic energy. Kant’s pre-critical writings, particularly his essay "Thoughts on the True Estimation of Living Forces," are examined to elucidate his methodological approach to this historical scientific dispute. The paper reconstructs Kant's strategy of employing thought experiments to mediate between the opposing Cartesian and Leibnizian camps, thereby addressing fundamental questions regarding the nature of force and movement. Through this reconstruction, the study clarifies how Kant leveraged imaginative reasoning to challenge existing theories and propose a cohesive methodological stance. The article adopts a rational reconstruction approach, systematically analyzing Kant’s pre-critical arguments as thought experiments. By employing comparative analysis, Kant’s reasoning is contextualized within both historical scientific discourse and contemporary philosophical interpretations of thought experimentation, particularly engaging with secondary literature on Kantian epistemology and philosophy of science. The novelty of this research lies in its explicit treatment of Kant's early arguments as genuine thought experiments, which has been overlooked in prior scholarship. The analysis demonstrates that Kant intentionally constructed his proofs as "experiments" – despite their hypothetical and counterfactual character—and considered them decisive even in the absence of empirical testing. The flexibility inherent in Kant’s imaginative approach enabled him to simultaneously critique and reconcile Leibniz's dynamic and Descartes's kinematic frameworks from a unified methodological perspective. Key conclusions include the recognition that Kant’s employment of thought experiments involving infinite variations, idealized experimental setups, and counterfactual conditions was crucial in shaping his methodological stance. Consequently, the article contributes significantly to understanding the continuity in Kant’s philosophical development from the pre-critical to the critical periods, emphasizing the methodological coherence underpinning his epistemological evolution.

living force, thought experiment, Kant, Leibniz, Descartes, kinetic energy, functional a priori, incongruent counterpart, momentum, imagination