Conservation laws in the Dirac theory

It is well known that the Dirac equations determine three conservation laws, for current, for energy momentum, and for angular momentum. Dividing the Dirac equations in two parts, one, D/sub I/, which does not contain the density rho, the other, D/sub II/, which contains rho, it is shown that D/sub I/ together with the three conservation equations, determine D/sub II/. From this result, a model of formulation of the Dirac theory is proposed, following a scheme similar to that of classical mechanics, in which principles regarding the motion of one particle are associated with conservation theorems concerning statistical ensembles of particles