All of modern physics is based on the principles of classical mechanics. For example, the conservation of energy and the conservation of momentum are principles which occur all over physics, including quantum mechanics.

There is one set of general rules which govern how nature evolves - the same set of rules that govern the motion of particles.

Physical systems are described by a space of states (or configurations), which, in classical mechanics, is a mathematical set. Also required are rules for updating the system, allowing it to go from one configuration to another.