The Complete Aristotle (eng.)

equality also. And since he is assumed to have no
more than his share, if he is just (for he does not assign to
himself more of what is good in itself, unless such a share is
proportional to his merits-so that it is for others that he
labours, and it is for this reason that men, as we stated
previously, say that justice is ‘another’s good’), therefore a
reward must be given him, and this is honour and privilege; but
those for whom such things are not enough become tyrants.
    The justice of a master and that of a father are not the same as
the justice of citizens, though they are like it; for there can be
no injustice in the unqualified sense towards thing that are one’s
own, but a man’s chattel, and his child until it reaches a certain
age and sets up for itself, are as it were part of himself, and no
one chooses to hurt himself (for which reason there can be no
injustice towards oneself). Therefore the justice or injustice of
citizens is not manifested in these relations; for it was as we saw
according to law, and between people naturally subject to law, and
these as we saw’ are people who have an equal share in ruling and
being ruled. Hence justice can more truly be manifested towards a
wife than towards children and chattels, for the former is
household justice; but even this is different from political
justice.
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7
    Of political justice part is natural, part legal, natural, that
which everywhere has the same force and does not exist by people’s
thinking this or that; legal, that which is originally indifferent,
but when it has been laid down is not indifferent, e.g. that a
prisoner’s ransom shall be a mina, or that a goat and not two sheep
shall be sacrificed, and again all the laws that are passed for
particular cases, e.g. that sacrifice shall be made in honour of
Brasidas, and the provisions of decrees. Now some think that all
justice is of this sort, because that which is by nature is
unchangeable and has everywhere the same force (as fire burns both
here and in Persia), while they see change in the things recognized
as just. This, however, is not true in this unqualified way, but is
true in a sense; or rather, with the gods it is perhaps not true at
all, while with us there is something that is just even by nature,
yet all of it is changeable; but still some is by nature, some not
by nature. It is evident which sort of thing, among things capable
of being otherwise, is by nature, and which is not but is legal and
conventional, assuming that both are equally changeable. And in all
other things the same distinction will apply; by nature the right
hand is stronger, yet it is possible that all men should come to be
ambidextrous. The things which are just by virtue of convention and
expediency are like measures; for wine and corn measures are not
everywhere equal, but larger in wholesale and smaller in retail
markets. Similarly, the things which are just not by nature but by
human enactment are not everywhere the same, since constitutions
also are not the same, though there is but one which is everywhere
by nature the best. Of things just and lawful each is related as
the universal to its particulars; for the things that are done are
many, but of them each is one, since it is universal.
    There is a difference between the act of injustice and what is
unjust, and between the act of justice and what is just; for a
thing is unjust by nature or by enactment; and this very thing,
when it has been done, is an act of injustice, but before it is
done is not yet that but is unjust. So, too, with an act of justice
(though the general term is rather ‘just action’, and ‘act of
justice’ is applied to the correction of the act of injustice).
    Each of these must later be examined separately with regard to
the nature and number of its species and the nature of the things
with which it is concerned.
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8
    Acts just and unjust being as we have described them, a man acts
unjustly or justly whenever he does such acts voluntarily; when
involuntarily, he acts neither unjustly nor justly except in an
incidental way; for he does things which happen to be just or
unjust. Whether an act is or is not one of injustice (or of
justice) is determined by its voluntariness or involuntariness; for
when it is voluntary it is blamed, and at the same time is then an
act of injustice; so that there will be things that are unjust but
not yet acts of injustice, if