LEIBNIZ ON FORCE, CAUSE AND SUBJECT OF MOTION: FROM DE CORPORUM CONCURSU (1678) TO THE BREVIS DEMONSTRATIO (1686)

Abstract In the present paper we study the relationship between the notions of force, cause and subject of motion in Leibniz’s early dynamics. First, we specify the role that the problem of the subject and cause of motion played in the development of his dynamics. Second, we analyze the distinction between force and quantity of motion and the validity and limits of his proof. Third, we study and evaluate the limits of the arguments for establishing that forces are inherent to bodies. Our main goal is to show that between 1678 and 1686 Leibniz dissociates the problem of the subject from the problem of the cause of motion and, furthermore, that even though the problem of establishing that force is inherent to particular bodies played a major role in the discovery of his dynamics, it has no place in its justification.