In classical mechanics, the Least Action Principle states that the motion of a particle along some path always minimize the difference between its kinetic energy and its potential energy. Mathematically, the motion of a particle always minimizes the Lagragian action functional. | In classical mechanics, the Least Action Principle states that the motion of a particle along some path always minimize the difference between its kinetic energy and its potential energy. Mathematically, the motion of a particle always minimizes the Lagragian action functional. |