An equation for describing the motion of a point electric charge, derived by classical electrodynamics. This equation is in accord with special relativity theory and avoids the self-energy problem. However, there are a number of difficulties, which are usually attributed to the fact that classical electrodynamics is not applicable to the point electron. The equation was derived by Paul Dirac in 1938, generalizing work in the late 19th century by H. A. Lorentz.