Little is known of Kant’s actual conversion. Only start and finish—Living Forces and Spin-Cycle—are present. But it does not take much imagination to fill in the blanks. In 1749, Kant promoted his book and waited for a reaction. When keeping track of the relevant journals, it could not have escaped him that Newton was the winner, nor that Leibnizian dynamics was on the wane and that support for Cartesian kinematics had all but collapsed. Force was Newtonian force. Newtonian physics had become the new paradigm of natural philosophy.