Some persons are of their own right; some are subject to the right of another.

Explanation

This maxim distinguishes those who hold full legal autonomy (sui juris) from those under another's authority (alieni juris), such as minors under a parent or wards under a guardian — the distinction determines who may bind himself by contract or appear in his own name.

Where this applies

• A seventeen-year-old tries to sign a binding lease, but the landlord requires a parent's co-signature because minors are not yet sui juris and cannot bind themselves alone.
• A court appoints a guardian ad litem for a mentally incapacitated adult, recognizing that he is no longer of his own right and needs someone to act on his behalf.
• A parent signs a medical consent form for her child, because the child is subject to the parent's authority and lacks the legal autonomy to consent independently.