It is impossible to be productive in any discussion when you are on the defense. When you become defensive you start spewing out negative energy. This negative energy can manifest in two ways; it can project outwards (Total Denial) or it can leak inwards (Total acceptance.) Either way, defensiveness is an all-or-nothing concept, and it places a great brick wall in communication.
Defensiveness is not a productive use of your energy. You spend all your energy trying to preserve your sense of self, that you end up giving away more energy in your reaction, when you could keep it within you and use it to restore your sense of calm, balance and security. Once you find your sense of calm, balance and security, you could then use the left over energy to start implementing changes in your life.
These are the two faces of defensiveness: