1. To keep people from coming into our space.
2. To keep us from going into the space of others.
3. To give each of us a way to embody our sense of "who we are".
Boundary systems have two parts. Internal and External.
Our external boundary allows us to choose our distance from other people and enables us to give or refuse permission for them to touch us or our private property. Our external boundary also keep our bodies from offending someone else's body.
Our internal boundary protects our thinking, feelings, and behavior and keeps them functional. When we are using our internal boundary, we can take responsibility for our thinking, feelings, and behavior and keep them separate from that of others, and stop blaming them for what we think, feel, and do. Our internal boundary also allows us to stop taking responsibility for the thoughts, feelings, and behaviors of others, allowing us to stop manipulating and controlling those around us.
With intact, flexible external and internal boundaries, people can have intimacy in their lives when they choose but are protected against being abused physically, sexually, emotionally, intellectually, or spiritually.
Pia Melody, Facing Codependency