Final answer:
The best example illustrating that Utopians value more practical items over money is their preference for iron over gold or silver. This reflects the concept of commodity money where intrinsic value is key, and contrasts with fiat money's symbolic value. The paradox of value also highlights the difference between essential items and luxury goods.
Step-by-step explanation:
The detail that best illustrates the central idea that the Utopians value money less than other, more useful things is "they must prefer iron either to gold or silver, for men can no more live without iron than without fire or water." This example directly links the usefulness of iron to essential aspects of life, like fire and water, emphasizing its practical importance over gold or silver. On the other hand, gold and silver do not have such essential uses and therefore do not hold as much value in this society. This perspective is a reflection of commodity money, where the barter system and the concept of intrinsic value in items like iron become more prominent than the symbolic value represented by money.
As coined by Ambrose Bierce, money is mainly a medium to facilitate exchange, and this utility is what gives money its value. Without money, as in barter systems, there's the issue of the double coincidence of wants, which makes trading cumbersome when you must find someone who has exactly what you want and who wants exactly what you have. Fiat money and commodity money differ in that fiat money, like the dollar bills we use today, has no intrinsic value beyond its function as legal tender, while commodity money, like gold or iron, has intrinsic value separate from its use as currency.
The paradox of value also comes into play here, where items of great utility like water may have low monetary value, while those with less practical use, such as diamonds, can be highly valued. This paradox underscores the distinction between survival needs and luxury desires, aligning with the Utopians' practical approach to value.