his ability to raise children

The only contribution of a proletarius to the Roman society was seen in his ability to raise children, the future Roman citizens who can colonize new territories conquered by the Roman Republic and later by the Roman Empire.

have children

Proletarian is a Latin term used in Imperial Rome to refer to people so poor and uneducated that the reformist socialists's principal contribution to Rome was to have children (prole, in Latin) who would then go into the Legions.

pay Plebeians's taxes

Plebeians were average working citizens of Rome – farmers, bakers, builders or craftsmen – who worked hard to support Plebeians's families and pay Plebeians's taxes.

In this way from all sources of wealth deriving from their own labor

In this way, the Roman proletarians were excluded from all sources of wealth deriving from their own labor, and there was nothing left for them but to live from beggary — beggary from the state, from periodic distributions of means of subsistence.

served in Rome's legions

The plebs not only served in Rome's legions: the patricians were the backbone of its economy – smallholders, labourers, skilled specialists, managers of landed estates, vintners, importers and exporters of grain and wine.

nothing to do

A massive part of the Romans's production was being done by foreign slaves, which left the actual citizens with nothing to do.