  The impossibility of an indeterministic evolution for standard relativistic
quantum field theories, that is, theories in which all fields satisfy the
condition that the generators of spacetime translation have spectrum in the
forward light-cone, is demonstrated. The demonstration proceeds by arguing that
a relativistically invariant theory must have a stable vacuum, and then showing
that stability of the vacuum, together with the requirements imposed by
relativistic causality, entails deterministic evolution, if all degrees of
freedom are standard degrees of freedom.
