If you insist. 
I wasn’t putting forward a theory.
You do have the legal right to protect yourself. Even in Italy. Even with a firearm.
Key word: yourself. You are not your property, and your property is not you. I.e., having the right to protect yourself from the threat of aggression (pericolo d’aggressione) is not the same as having the right to murder someone just because he’s in your home without an invitation.
Your loved ones are not your property either, but they have selves you can also protect.
(No English version available. Disclaimer: this is not an endorsement of Italian law.)