The Complete Aristotle (eng.)

upon this plan they all
govern; just as if shoemakers and carpenters were to exchange their
occupations, and the same persons did not always continue
shoemakers and carpenters. And since it is better that this should
be so in politics as well, it is clear that while there should be
continuance of the same persons in power where this is possible,
yet where this is not possible by reason of the natural equality of
the citizens, and at the same time it is just that an should share
in the government (whether to govern be a good thing or a bad), an
approximation to this is that equals should in turn retire from
office and should, apart from official position, be treated alike.
Thus the one party rule and the others are ruled in turn, as if
they were no longer the same persons. In like manner when they hold
office there is a variety in the offices held. Hence it is evident
that a city is not by nature one in that sense which some persons
affirm; and that what is said to be the greatest good of cities is
in reality their destruction; but surely the good of things must be
that which preserves them. Again, in another point of view, this
extreme unification of the state is clearly not good; for a family
is more self-sufficing than an individual, and a city than a
family, and a city only comes into being when the community is
large enough to be self-sufficing. If then self-sufficiency is to
be desired, the lesser degree of unity is more desirable than the
greater.
III
    But, even supposing that it were best for the community to have
the greatest degree of unity, this unity is by no means proved to
follow from the fact ‘of all men saying “mine” and “not mine” at
the same instant of time,’ which, according to Socrates, is the
sign of perfect unity in a state. For the word ‘all’ is ambiguous.
If the meaning be that every individual says ‘mine’ and ‘not mine’
at the same time, then perhaps the result at which Socrates aims
may be in some degree accomplished; each man will call the same
person his own son and the same person his wife, and so of his
property and of all that falls to his lot. This, however, is not
the way in which people would speak who had their had their wives
and children in common; they would say ‘all’ but not ‘each.’ In
like manner their property would be described as belonging to them,
not severally but collectively. There is an obvious fallacy in the
term ‘all’: like some other words, ‘both,’ ‘odd,’ ‘even,’ it is
ambiguous, and even in abstract argument becomes a source of
logical puzzles. That all persons call the same thing mine in the
sense in which each does so may be a fine thing, but it is
impracticable; or if the words are taken in the other sense, such a
unity in no way conduces to harmony. And there is another objection
to the proposal. For that which is common to the greatest number
has the least care bestowed upon it. Every one thinks chiefly of
his own, hardly at all of the common interest; and only when he is
himself concerned as an individual. For besides other
considerations, everybody is more inclined to neglect the duty
which he expects another to fulfill; as in families many attendants
are often less useful than a few. Each citizen will have a thousand
sons who will not be his sons individually but anybody will be
equally the son of anybody, and will therefore be neglected by all
alike. Further, upon this principle, every one will use the word
‘mine’ of one who is prospering or the reverse, however small a
fraction he may himself be of the whole number; the same boy will
be ‘so and so’s son,’ the son of each of the thousand, or whatever
be the number of the citizens; and even about this he will not be
positive; for it is impossible to know who chanced to have a child,
or whether, if one came into existence, it has survived. But which
is better—for each to say ‘mine’ in this way, making a man the same
relation to two thousand or ten thousand citizens, or to use the
word ‘mine’ in the ordinary and more restricted sense? For usually
the same person is called by one man his own son whom another calls
his own brother or cousin or kinsman—blood relation or connection
by marriage either of himself or of some relation of his, and yet
another his clansman or tribesman; and how much better is it to be
the real cousin of somebody than to be a son after Plato’s fashion!
Nor is there any way of preventing brothers and children