I have learned to define Internal Boundaries for myself as follows:
Internal Boundaries: What you allow or do not allow to bother you inside.
- What gets you upset?
- What causes you to react?
The key to being autonomous and free is to trust your own self, to know your own self and to act in accordance with your own best interests at all times from a place of centeredness. The key to abandoning yourself is to allow yourself to be swept away by the whims of others, or to be manipulated and to have your own will usurped by the desires of others. Good internal boundaries help you to hold onto yourself and not be swept away in the chaos, drama and needs of others.
You can improve your internal boundaries by getting to know yourself and learning how you're feeling at any given moment and to assert your own boundaries within prior to setting limits without of yourself. Internal boundaries can become and often are automatic, but can also require you to heed your intuition. Trusting your gut and acting in accordance with your gut no matter who is demanding you to do otherwise is a good example of having a strong internal boundary.
Related:
Internal Locus of Control