Maybe you can have a look on John Locke's Second Treatise, where he 
claims that civil society </wiki/Civil_society> (vs the state of nature) 
was created by men by an agreement pactum unionis for the protection of  
</wiki/Property> "life, liberty, and estate" he considers inalienable 
rights (in disagrement with Hobbes who defined just life the only 
inalienable right) .

Giandomenica Becchio