The ancient Greek example has already shown the Lib Dems how to enact the Mansion Tax. Now the Romans must step in to explain how to bring about the full-blown wealth tax they so ardently covet.
The historian Livy says that an early king, Servius Tullius (traditional dates 578-534 BC), invented the idea of raising money through a wealth tax, i.e. a tax on property. Its purpose was to compensate soldiers for loss of income during long campaigns. The problem was the vast disparity of the property that anyone owned. So Servius came up with the idea of ensuring that the wealthiest paid the most. He did this by creating seven bands of citizens, from the wealthiest to the poorest, defined by their capacity to provide military resources.
The top band consisted of the sort of people who could run a stable of horses (rather like owning a stable of racing cars today) — they were the ‘cavalry’ (equites) for military purposes — the next five bands of those who could provide a decreasing level of military equipment, down to the last band, those who had nothing to offer but children. These proletarii (proles, ‘offspring’), were also known as capite censi, lit. ‘counted by head’ (cf. ‘head-count’, ‘per head’), caput also meaning ‘person, individual’. The higher your ‘band’, the more you paid.
But in the absence of a civil service or Sunday Times ‘rich list’, how did the Romans identify anyone’s ‘band’? Every four or five years, before a body of ‘censors’, each citizen had to give his name, age, family details and full account of his property and its value, often quite detailed (jewellery, carriages, etc). Death, imprisonment or slavery were the available penalties for those who failed to appear without due cause. Further, this census took place in public. The presence of neighbours would presumably act as a strong incentive to tell something like the truth.
Problem solved. Lib Dems could then make the censors overseers of public morality, as Romans did, ushering in the closest approximation possible to a Lib Dem heaven-on-earth.