1. The economy is very largely monetized.
The use of money is indispensable for commodity exchanges, just as monetary transfers are the norm for subsidies. This convenience is vital, as it overcomes the considerable inefficiency inherent in a system of generalized barter or payment of taxes in kind.
2. This convenience has disadvantages which would disappear only if the currencies in circulation were so good at preserving exchange value that a loss or gain of purchasing power would never result from their use.
Should economic science be built first on the hypothesis of monetary perfection in order to later bring to light, among the monetary organizations observed and conceivable, the most adequate? The negative answer diminishes, or even annihilates, the ability to find the best way.
3. The model of pure and perfect competition and the hypothesis of monetary perfection do not have the same status.
The model of pure and perfect competition reduces the regulation of the freedom to offer by the freedom to choose to what it does not have to be in order to exist, as Schumpeter was one of the first to show. The hypothesis of monetary perfection neutralizes a variable until it is discerned that currencies that are legal tender should disrupt as little as possible.
4. The principle of legal tender is so simple that we tend to lose sight of it.
In the geographical area where a currency is legal tender, no payment may be refused on the grounds that it is made in that currency. In this way, a currency that is legal tender is endowed with an unquestionable discharging power in law.
A currency is forced tender when it is inconvertible into gold or any other metal that can be used to calibrate it. Legal tender and forced tender of a currency are combinable and separable.