There are people who have a notion that Reciprocation is simply just,
as the Pythagoreans said: for they defined the Just simply and without
qualification as “That which reciprocates with another.” But this
simple Reciprocation will not fit on either to the Distributive Just,
or the Corrective (and yet this is the interpretation they put on the
Rhadamanthian rule of Just,
If a man should suffer what he hath done, then there would be
straightforward justice;”)
for in many cases differences arise: as, for instance, suppose one in
authority has struck a man, he is not to be struck in turn; or if a man
has struck one in authority, he must not only be struck but punished
also.[16] And again, the voluntariness or involuntariness of actions
makes a great difference.
But in dealings of exchange such a principle of Justice as this
Reciprocation forms the bond of union, but then it must be
Reciprocation according to proportion and not exact equality, because
by proportionate reciprocity of action the social community is held
together, For either Reciprocation of evil is meant, and if this be not
allowed it is thought to be a servile condition of things: or else
Reciprocation of good, and if this be not effected then there is no
admission to participation which is the very bond of their union.
And this is the moral of placing the Temple of the Graces (χάριτες) in
the public streets; to impress the notion that there may be requital,
this being peculiar to χάρις[17] because a man ought to requite with a
good turn the man who has done him a favour and then to become himself
the originator of another χάρις, by doing him a favour.
Now the acts of mutual giving in due proportion may be represented by
the diameters of a parallelogram, at the four angles of which the
parties and their wares are so placed that the side connecting the
parties be opposite to that connecting the wares, and each party be
connected by one side with his own ware, as in the accompanying
diagram.
[Illustration]
The builder is to receive from the shoemaker of his ware, and to give
him of his own: if then there be first proportionate equality, and
_then_ the Reciprocation takes place, there will be the just result
which we are speaking of: if not, there is not the equal, nor will the
connection stand: for there is no reason why the ware of the one may
not be better than that of the other, and therefore before the exchange
is made they must have been equalised. And this is so also in the other
arts: for they would have been destroyed entirely if there were not a
correspondence in point of quantity and quality between the producer
and the consumer. For, we must remember, no dealing arises between two
of the same kind, two physicians, for instance; but say between a
physician and agriculturist, or, to state it generally, between those
who are different and not equal, but these of course must have been
equalised before the exchange can take place.
It is therefore indispensable that all things which can be exchanged
should be capable of comparison, and for this purpose money has come
in, and comes to be a kind of medium, for it measures all things and so
likewise the excess and defect; for instance, how many shoes are equal
to a house or a given quantity of food. As then the builder to the
shoemaker, so many shoes must be to the house (or food, if instead of a
builder an agriculturist be the exchanging party); for unless there is
this proportion there cannot be exchange or dealing, and this
proportion cannot be unless the terms are in some way equal; hence the
need, as was stated above, of some one measure of all things. Now this
is really and truly the Demand for them, which is the common bond of
all such dealings. For if the parties were not in want at all or not
similarly of one another’s wares, there would either not be any
exchange, or at least not the same.
And money has come to be, by general agreement, a representative of
Demand: and the account of its Greek name νομισμα is this, that it is
what it is not naturally but by custom or law (νόμος), and it rests
with us to change its value, or make it wholly useless.
Very well then, there will be Reciprocation when the terms have been
equalised so as to stand in this proportion; Agriculturist : Shoemaker
: : wares of Shoemaker : wares of Agriculturist; but you must bring
them to this form of proportion when they exchange, otherwise the one
extreme will combine both exceedings of the mean:[18] but when they
have exactly their own then they are equal and have dealings, because
the same equality can come to be in their case. Let A represent an
agriculturist, C food, B a shoemaker, D his wares equalised with A’s.
Then the proportion will be correct, A:B::C:D; _now_ Reciprocation will
be practicable, if it were not, there would have been no dealing.
Now that what connects men in such transactions is Demand, as being
some one thing, is shown by the fact that, when either one does not
want the other or neither want one another, they do not exchange at
all: whereas they do[19] when one wants what the other man has, wine
for instance, giving in return corn for exportation.
And further, money is a kind of security to us in respect of exchange
at some future time (supposing that one wants nothing now that we shall
have it when we do): the theory of money being that whenever one brings
it one can receive commodities in exchange: of course this too is
liable to depreciation, for its purchasing power is not always the
same, but still it is of a more permanent nature than the commodities
it represents. And this is the reason why all things should have a
price set upon them, because thus there may be exchange at any time,
and if exchange then dealing. So money, like a measure, making all
things commensurable equalises them: for if there was not exchange
there would not have been dealing, nor exchange if there were not
equality, nor equality if there were not the capacity of being
commensurate: it is impossible that things so greatly different should
be really commensurate, but we can approximate sufficiently for all
practical purposes in reference to Demand. The common measure must be
some one thing, and also from agreement (for which reason it is called
νόμισμα), for this makes all things commensurable: in fact, all things
are measured by money. Let B represent ten minæ, A a house worth five
minæ, or in other words half B, C a bed worth 1/10th of B: it is clear
then how many beds are equal to one house, namely, five.
It is obvious also that exchange was thus conducted before the
existence of money: for it makes no difference whether you give for a
house five beds or the price of five beds.