It cannot be that man has to be immoral. It must be that a (self) blameless life can be lived.
An average man needs an acre of reasonable land to live self-sufficiently by his own efforts of about 20 hours a week.
If a man is not to be born a slave to others, it must be expected that even with impoverished parents, when he comes off age he can live by his own efforts without the indulgence of others (even his impoverished parents who have nothing to spare for him).
Clearly he requires an acre of land to set his life account balance to zero - so he may (if he chooses) live his life without having call or being a burden on others, nor they on him.
With technology it is clear that one man farming an acre (or more realistically) an independent family of five farming five acres may not be the most efficient method of farming, it may be that the land could be more productive if farmed on a larger scale.
However, it is for the current owners to decide if they would allow this - and it would be stupid to allow someone else to farm their land unless they receive at least as much produce as had they farmed it themselves, and shelter. The price of a perpetual supply of food cannot be less than the supply of perpetual food. And if land ownership is transferable, the price must reflect that it is for ever, not just the life time of the current occupants.
Each free Englishman should receive a non transferable life time lease on one (notional) acre of English soil. Which, if circumstances permit he may choose, instead, to receive the rent from - assured that this will feed and house him. His land generating his citizens income - no favours asked our received.
Who will give him this acre? The free people of England shall. As pointed out right at the start to deprive someone of this is to enslave them, and to jealously guard the tools of an others slavery can have no moral foundation. 80,000,000 people, 80,000,000 (notional) acres - one is yours for life, more than that you must rent from others...
(Note the possibility of one acre per person is a fortunate outcome of the size and population of the UK - and while many acres are not farm-able, other revenues have not been included, nor the seas and their sticks of fish).
In practice each free Englishman receives an equal share of the gross national rent - this would be a citizens income, meaning no centralised benefits would be required.
Existing 'land owners' would need to consider whether they will pay the rent for what they currently control or relinquish that control to others who may want to rent it and are prepared to pay more to do so.
It may be that little changes in practice, other than a rational, practical and moral basis for the citizens income being established..