  A certain non-linear non-local substitution is shown to transform the action
of the self-interacting quantum field to the free one. The functional integrals
in both theories are equal to each other. However, the integrations are
performed over different functional spaces. The classical action and the
classical limit of the corresponding quantum theory turn out to be different.
And the symmetry originally broken in the classical theory is restored in the
classical limit of the quantum theory.
