ABSTRACT
The discipline of mechanics has traditionally been thought of as comprising three areas: statics deals with bodies in a state of equilibrium, kinematics with moving bodies, and dynamics deals with the forces responsible for motion. The ultimate prize of seventeenth-century physical theory was the last. Statics dealt with forces but not with motion; kinematics, on the other hand, dealt with motion but not with forces. Dynamics had to deal with both. Broadly speaking, this suggests two routes to dynamics. The first route is via statics. Since statics does not deal with moving bodies, but does deal with forces, the aim is to extrapolate the treatment of forces used to describe stationary bodies into the realm of moving bodies, e.g. by asking how these forces are modified or supplemented when the stationary body begins to move in a particular way. The advantage of this approach was that statics had been pursued since Archimedes in a precise, quantitative, geometrical fashion, which was exactly how seventeenth-century natural philosophers wished to pursue dynamics. The second route is via kinematics. Kinematics does not deal with forces but, at least from Galileo’s Two New Sciences (1638) onwards, it does provide a precise, quantitative, geometrical account of motion, and for those who pursued this route to dynamics, the thought was that the kinematic analysis and classification of motions into various categories might yield the fundamental kinds of motion and rest, so that one could then associate different forces with these different fundamental states, and thereby explain what made them different.
