The plebeians, on the contrary, were entitled to the enjoyment of only a little pasture-land left to them in common: an utterly unjust state of things, since, in consequence of it, taxation--_census_--weighed more heavily upon the poor than upon the rich.

The patrician, in fact, always exempted himself from the tithe which he owed as the price and as the acknowledgment of the concession of domain; and, on the other hand, paid no taxes on his POSSESSIONS, if, as there is good reason to believe, only citizens' property was taxed."-- Laboulaye: History of Property.
In order thoroughly to understand the preceding quotation, we must know that the estates of CITIZENS--that is, estates independent of the public domain, whether they were obtained in the division of Numa, or had since been sold by the questors--were alone regarded as PROPERTY; upon these a tax, or _cense_, was imposed.

On the contrary, the estates obtained by concessions of the public domain, of the ager publicus (for which a light rent was paid), were called POSSESSIONS.

Thus, among the Romans, there was a RIGHT OF PROPERTY and a RIGHT OF POSSESSION regulating the administration of all estates.

Now, what did the proletaires wish?
That the jus possessionis--the simple right of possession--should be extended to them at the expense, as is evident, not of private property, but of the public domain,--agri publici.