Chapter 5: Simple requital is not identical with what is just, but proportionate requital is what is just in exchange; and this is effected by means of money. We can now give a general definition of justice (2).

Some people, indeed, go so far as to think that simple requital is just. And so the Pythagoreans used to teach; for their definition of what is just was simply that what a man has done to another should be done to him.

But this simple requital does not correspond either with that which is just in distribution or with that which is just in the way of redress (though they try to make out that this is the meaning of the Rhadamanthine rule—

for in many cases it is quite different. For instance, if an officer strike a man, he ought not to be struck in return; and if a man strike an officer, he ought not merely to be struck, but to be punished.

Further, it makes a great difference whether what was done to the other was done with his consent or against it.

But it is true that, in the interchange of services, this is the rule of justice that holds society together, viz. requital—but proportionate requital, and not simple repayment of equals for equals. For the very existence of a state depends upon proportionate return. If men have suffered evil, they seek to return it; if not, if they cannot requite an injury, we count their condition slavish. And again, if men have received good, they seek to repay it: for otherwise there is no exchange of services; but it is by this exchange that we are bound together in society.

This is the reason why we set up a temple of the graces [charities, χάριτες] in sight of all men, to remind them to repay that which they receive; for this is the special characteristic of charity or grace. We ought to return the good offices of those who have been gracious to us, and then again to take the lead in good offices towards them.

But proportionate interchange is brought about by “cross conjunction.”

For instance, let A stand for a builder, B for a shoemaker, C for a house, D for shoes.

The builder then must take some of the shoemaker’s work, and give him his own work in exchange.

Now, the desired result will be brought about if requital take place after proportionate equality has first been established.*

If this be not done, there is no equality, and intercourse becomes impossible; for there is no reason why the work of the one should not be worth more than the work of the other. Their work, then, must be brought to an equality [or appraised by a common standard of value].

This is no less true of the other arts and professions [than of building and shoemaking]; for they could not exist if that which the patient [client or consumer] receives did not correspond in quantity and quality with that which the agent [artist or producer] does or produces.

For it is not between two physicians that exchange of services takes place, but between a physician and a husbandman, and generally between persons of different professions and of unequal worth; these unequal persons, then, have to be reduced to equality [or measured by a common standard].

All things or services, then, which are to be exchanged must be in some way reducible to a common measure.

For this purpose money was invented, and serves as a medium of exchange; for by it we can measure everything, and so can measure the superiority and inferiority of different kinds of work—the number of shoes, for instance, that is equivalent to a house or to a certain quantity of food.

What is needed then is that so many shoes shall bear to a house (or a measure of corn) the same ratio that a builder [or a husbandman] bears to a shoemaker.† For unless this adjustment be effected, no dealing or exchange of services can take place; and it cannot be effected unless the things to be exchanged can be in some way made equal.

We want, therefore, some one common measure of value, as we said before.

This measure is, in fact, the need for each other’s services which holds the members of a society together; for if men had no needs, or no common needs, there would either be no exchange, or a different sort of exchange from that which we know.

But money has been introduced by convention as a kind of substitute for need or demand; and this is why we call it νόμισμα, because its value is derived, not from nature, but from law (νόμος), and can be altered or abolished at will.

Requital then will take place after the wares have been so equated [by the adjustment of prices] that the quantity of shoemaker’s work bears to the quantity of husbandman’s work [which exchanges for it] the same ratio that husbandman bears to shoemaker. But this adjustment must be made, not at the time of exchange (for then one of the two parties would get both the advantages), but while they are still in possession of their own wares; if this be done, they are put on an equal footing and can make an exchange, because this kind of equality can be established between them.

If A stand for a husbandman and C for a certain quantity of his work (or corn), B will stand for a shoemaker, and D for that quantity of shoemaker’s work that is valued as equal to C.

If they could not requite each other in this way, interchange of services would be impossible.

That it is our need which forms, as it were, a common bond to hold society together, is seen from the fact that people do not exchange unless they are in need of one another’s services (each party of the services of the other, or at least one party of the service of the other), as when that which one has, e.g.wine, is needed by other people who offer to export corn in return. This article, then [the corn to be exported], must be made equal [to the wine that is imported].*

But even if we happen to want nothing at the moment, money is a sort of guarantee that we shall be able to make an exchange at any future time when we happen to be in need; for the man who brings money must always be able to take goods in exchange.

Money is, indeed, subject to the same conditions as other things: its value is not always the same; but still it tends to be more constant than the value of anything else.

Everything, then, must be assessed in money; for this enables men always to exchange their services, and so makes society possible.

Money, then, as a standard, serves to reduce things to a common measure, so that equal amounts of each may be taken; for there would be no society if there were no exchange, and no exchange if there were no equality, and no equality if it were not possible to reduce things to a common measure.

In strictness, indeed, it is impossible to find any common measure for things so extremely diverse; but our needs give a standard which is sufficiently accurate for practical purposes.

There must, then, be some one common symbol for this, and that a conventional symbol; so we call it money (νόμισμα, νόμος). Money makes all things commensurable, for all things are valued in money. For instance, let A stand for a house, B for ten minæ, C for a bed; and let A = B/2, taking a house to be worth or equal to five minæ, and let C (the bed) = B/10. We see at once, then, how many beds are equal to one house, viz. five.

It is evident that, before money came into use, all exchange must have been of this kind: it makes no difference whether you give five beds for a house, or the value of five beds.

Thus we have described that which is unjust and that which is just. And now that these are determined, we can see that doing justice is a mean between doing and suffering injustice; for the one is having too much, or more, and the other too little, or less than one’s due.

We see also that the virtue justice is a kind of moderation or observance of the mean, but not quite in the same way as the virtues hitherto spoken of. It does indeed choose a mean, but both the extremes fall under the single vice injustice.

We see also that justice is that habit in respect of which the just man is said to be apt to do deliberately that which is just; that is to say, in dealings between himself and another (or between two other parties), to apportion things, not so that he shall get more or too much, and his neighbour less or too little, of what is desirable, and conversely with what is disadvantageous, but so that each shall get his fair, that is, his proportionate share, and similarly in dealings between two other parties.

Injustice, on the contrary, is the character which chooses what is unjust, which is a disproportionate amount, that is, too much and too little of what is advantageous and disadvantageous respectively.

Thus injustice, as we say, is both an excess and a deficiency, in that it chooses both an excess and a deficiency—in one’s own affairs choosing excess of what is, as a general rule, advantageous, and deficiency of what is disadvantageous; in the affairs of others making a similarly disproportionate assignment, though in which way the proportion is violated will depend upon circumstances.

But of the two sides of the act of injustice, suffering is a lesser wrong than doing the injustice.

Let this, then, be accepted as our account, in general terms, of the nature of justice and injustice respectively, and of that which is just and that which is unjust.