It has been long remarked, and justly, that commerce, properly so called, i.e. the transportation of raw materials or finished products, from one market to another, by adding to the worth of the objects transported, creates value or wealth in just the same way as the labour of the miner who extracts metals from the bowels of the earth, or the workman who adapts them to our needs. What ought to have been added, and what we shall have occasion to develop, is that commerce may also be a cause of destruction of values, even while making profits for the merchants who carry it on, and even when in every one's eyes it is a benefit to the countries which it connects in commercial intercourse.
A fashion, a whim, or a chance occurrence may cause a creation or annihilation of values without notable influence on what is regarded as public utility or the general welfare; it can even come about that a destruction of wealth may be salutary, and an increase detrimental. If chemists should solve the problem of making diamonds, jewellers and the ladies who own sets of jewellery would suffer heavy losses; the general mass of wealth capable of circulation would experience a notable decrease, and yet I can hardly think than any sensible man would be tempted to consider it a public calamity, even though he might regret the individual losses involved. On the contrary, if the taste for diamonds should decline, if wealthy people should stop devoting an important part of their fortunes to this idle vanity, and if, in consequence, the value of diamonds in commerce should decrease, wise men would gladly commend this new departure of fashion.