When anything that is desirable is to be had by labour, and is not to be had without labour, of course we find men labouring to obtain it; and things that are of very great value, will usually be found to have cost very great labour. This has led some persons to suppose that it is the labour which has been bestowed on anything that gives it value. But this is quite a mistake. It is not the labour which anything has cost that causes it to sell for a high price; but on the contrary, it is its selling for a high price that causes men to labour in procuring it. For instance, fishermen go out to sea, and toil hard in the wet and cold to fish, because they can get a good price for them; but if a fisherman should work hard all night, and catch but one small fish, while another had, perhaps, caught a thousand, by falling in with a shoal, the first would not be able to sell his one fish for the same price as the other man’s thousand. It has now and then happened that a salmon or a sturgeon has leaped into a boat by chance; but though this has cost no labour, it is not for that reason the less valuable. And if a man, in eating an oyster, should chance to meet with a fine pearl, it would sell for no less than if he had been diving for it all day.