Thomas Paine (1737-1809):

Men did not make the earth... It is the value of the improvements only, and not the earth itself, that is individual property... Every proprietor owes to the community a ground rent for the land which he holds.

Pope Gregory the Great (540-604 AD)

"Cura Pastoralis": Those who make private property of the gift of God pretend in vain to be innocent. For, in thus retaining the subsistence of the poor, they are the murderers of those who die every day for the want of it.