They do not shut people out. We use them to protect ourselves. We use barriers as a means of defence. They allow nothing in and nothing out. Barricaded, we get no nourishment and cannot share our gifts.
Healthy boundaries are like a filter.
They shut out what we don't want and let in what we do. They allow us to give and take. They are flexible and changing. Defensive barriers are tight and rigid. We use them for survival only.