  For a real nonlinear Klein-Gordon Lagrangian density with a special solitary
wave solution (SSWS), which is essentially unstable, it is shown how adding a
proper additional massless term could guarantee the energetically stability of
the SSWS, without changing its dominant dynamical equation and other
properties. In other words, it is a stability catalyzer. The additional term
contains a parameter $B$, which brings about more stability for the SSWS at
larger values. Hence, if one considers $B$ to be an extremely large value, then
any other solution which is not very close to the free far apart SSWSs and the
trivial vacuum state, require an infinite amount of energy to be created. In
other words, the possible non-trivial stable configurations of the fields with
the finite total energies are any number of the far apart SSWSs, similar to any
number of identical particles.
