Although Wolff has just spoken in considerable detail about donations, he does note that usually we expect to receive something in return, when we give or do things to another person. Indeed, Wolff continues, if the other person can give or do something in turn, we are entitled to expect that they do. We can even expect that they will give or do something in the same ratio as we have given or done to them.
The phrase “same ratio” already presupposes that we can somehow quantify things we give or do. In other words, we expect them to have a specific value that we can determine. Now, Wolff notes that value of things is at least partially arbitrary - there is nothing in a piece of furniture to suggest that it should be tradable to so and so many bananas. Yet, Wolff at once concedes, we can at least insist that value is at least proportional to certain physical quantity. In other words, if a kilo of potatoes or an hour of work has a definite value, then two kilos of potatoes and two hours of work have double of that value.
In addition, Wolff also notes that the value of things should be determined by their place in economic processes. Thus, a price of land should reflect its possible produce, while the price of an industrial product is to be determined by the prices of the raw materials used for the thing, the price of work required in doing the product and other expenses. Wolff also notes that some ethical rules should govern the prices. For instance, we should take care that the most necessary things would have a smaller price than luxury items.
Determining the value of a thing in comparison to another thing is not an easy task. Hence, Wolff concludes, to simplify transactions we should choose a certain class of corporeal things as a common measure of value, that is, as money. This money, Wolff says should consist of some truly durable matter that will not be corrupted by rust nor won’t spoil. Then again, he also notes that money should consist of matter that is not needed for much else beyond its use as a measure of value. Finally, he concludes, money should consist of rare matter, so that its own value would be stable enough.These criteria suggest, Wolff concludes, that gold and silver are optimal raw materials for money.
Just like with all other countable things, Wolff continues, the price of money should be proportional to its quantity, or more precisely, its weight. To make it easier to know how much money weighs, gold or silver should be cut into small proportions or coins, with the weight of the coin stamped on it. This marking on a coin should be a reliable sign of its weight, thus, Wolff concludes, coins should not be forged e.g. by mixing baser metals with gold and silver.
Existence of money makes it possible to estimate how wealthy a person is - just turn all the property of a person into its monetary price, subtract possible debts and consider what kind of things the person could buy with that quantity of money. Wolff delineates several levels of things one could purchase with money. The lowest level is formed by necessities, which are essential for keeping a human being alive. A step further is the level of commodities, which are not as necessary, but still useful for everyday life. Above commodities is the level of jucundities, that is, things which make life pleasant, and above them, things required by decorum. Whatever remains beyond that level, Wolff concludes, is superfluous luxury.
Now, Wolff defines poverty as a state in which a person can afford at most only the necessities of life, if even those. On the contrary, a rich person is such that can afford even superfluities. Wolff gives some laughably obvious tricks for avoiding poverty, “spend less than you produce” being the most trivial. Still, he does not regard poverty as mere sign of laziness or reckless behaviour. Instead, he insists that poverty is just bad fortune, just like richness is also just good fortune. Wolff also suggests that it is decorate that rich people should try to equalise the gap between the rich and the poor by donating some of their money to the poor.
