he desires to benefit his fellow-men. The money which he receives (as we do not propose to consider here any questions regarding the currency) we may regard as simply a certificate that he has done a certain amount of work for the world, the measure of which is the number of dollars he receives; and on presentation of that certificate, he can obtain other articles which he desires.
We have next to consider the fact that there is a great variation in the amount which a man can take out from this common stock. One man is able to provide himself from the common stock with a host of luxuries, while another may only take out a scant supply of the barest necessaries of life. If this distribution operated with perfect equity, a man would be permitted to take out of this common stock exactly in proportion to the benefit which the world at large received from that which he put in. No human judgment, however, is competent to fix, with even an approach to precision, the relative actual benefit which each member of society renders to his fellow-men as a whole. But our social system effects that for us better than it could be fixed by any arbitrary human judgment. This it does by a law known as the law of supply and demand. Instead of the actual benefit, this law takes what people choose to consider as benefit, which is the granting of their desires, whether they desire things hurtful or beneficial. It is these desires for things which others can produce which constitute demand. It is to be borne in mind that this is a broad term, and includes not only desires for food, clothing, and actual things, but for service of every sort, in short, demand is the desire for any thing whatever for which people are willing to pay money. But when there is this demand—this willingness to pay money for any article—people begin at once to supply it, because the money they receive allows them to take goods which they wish from the common stock. Evidently, if there is an unlimited supply of any thing, people will not pay money for it. People will not pay money for fresh air to breathe when they are out-of-doors, and the supply is unlimited; but when indoors, the supply may be limited, and they will spend money to have ventilators and air-pipes