Fundamental forces and their dynamics

 We would like to pronounce a general principle that the dynamics or
 the equation of motion of a fundamental force must not be prescribed but instead
 be governed by the geometry of the corresponding spacetime manifold and it follows
 from the purely geometric property -- the celebrated Bianchi differential identity
 without appeal to the action principle. Following this dictum we shall derive the
 equations of motion of all the four fundamental forces. We would also discuss some
 new insights that may ensue from it.