Marius Stan

Unity for Kant’s Natural Philosophy

I uncover here a conflict in Kant’s natural philosophy. His matter theory and laws of mechanics are in tension. Kant’s laws are fit for particles but are too narrow to handle continuous bodies, which his doctrine of matter demands. To fix this defect, Kant ultimately must ground the Torque Law; that is, the impressed torque equals the change in angular momentum. But that grounding requires a premise—the symmetry of the stress tensor—that Kant denies himself. I argue that his problem would not arise if he had kept his early theory of matter as made of mass points, or “physical monads.”

Huygens on Inertial Structure and Relativity

I explain and assess here Huygens’s concept of relative motion. I show that it allows him to ground most of the Law of Inertia and also to explain rotation. Thereby his concept obviates the need for Newton’s absolute space. Thus, his account is a powerful foundation for mechanics, although not without some tension.

From General to Special Metaphysics of Nature

In his Metaphysical Foundations of Natural Science, Kant presents the “pure part” of natural science – that is, the a priori principles holding of matter. This special metaphysics of matter is, Kant claims, grounded on the general metaphysics of nature described in the System of Principles of his first Critique. This chapter develops a comprehensive account of Kant’s framework for natural science that touches on interpretive issues that arise in the transition from general to special metaphysics and that outlines his dynamics and its limitations.

Newton's Concepts of Force among the Leibnizians

I argue that the key dynamical concepts and laws of Newtons Principia never gained a solid foothold in Germany before Kant in the 1750s. I explain this absence as due to Leibniz. Thus I make a case for a robust Leibnizian legacy for Enlightenment science, and I solve what Jonathan Israel called “a meaningful historical problem on its own,” viz. the slow and hesitant reception of Newton in pre-Kantian Germany.