22. Cultivation by slaves cannot exist in great societies.
Thus when men are formed into great societies, the recruits
of slaves are not sufficiently numerous to support the
consumption which the cultivation requires. And although they
supply the labour of men by that of beasts, a time will come,
when the lands can no longer be worked by slaves. The practice is
then continued only for the interior work of the house, and in
the end it is totally abolished; because in proportion as nations
become polished, they form conventions for the exchange of
prisoners of war. These conventions are the more readily made, as
every individual is very much interested to be free from the
danger of falling into a state of slavery.
