This is proved over and over by the constant relapse into "nerves" which comes to those who have simply been healed over.

Even with those who appear to have been well for some time, if they have not acquired the habit of dropping their mental and physical tension you can always detect an overcare for themselves which means dormant fear--or even active fear in the background.
There are some wounds which the surgeons keep open, even though the process is most painful, because they know that to heal really they must heal from the inside.

Healing over on the outside only means decay underneath, and eventual death.

This is in most cases exactly synonymous with the healing of broken-down nerves.

They must be healed in causes to be permanently cured.