Self-force of a classical charged particle

An analysis of the motion of a classical charged particle in its self-field is carried out. The original study of Dirac in 1938 [Proc. R. Soc. London, Ser. A 167, 148 (1938)] made use of the energy-momentum tensor to conclude that the retarded minus the advanced fields must be used in the limit onto the source. In this paper, a criterion based on the vanishing of the total force on an uncharged system is used to arrive, in quite a different way, at the same formula. Some insights are provided by this method. It is shown that there is a basic inconsistency in this construction for the case of a two-body system with zero net charge if the two masses are not equal. Application of Diracs formula to the unequal-mass case results in the same inconsistency. The case of the massless charged particle is also considered.