  In order for Dirac theory to be gauge invariant it can be shown that the
Schwinger term must be zero. However, it can also be shown that for the vacuum
state to be the lowest energy state the Schwinger term must be nonzero.
Therefore there is an inconsistency in Dirac theory involving the evaluation of
the Schwinger term. This inconsistency is discussed along with a possible way
to resolve it.
