Page:Sir William Petty - A Study in English Economic Literature - 1894.djvu/63

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Money is defined as the uniform measure and rule for the value of all commodities (346). This is only a definition, for he expresses a doubt whether there has ever been such a measure (30). The world measures commodities by gold and silver, but these measures do not fulfil the conditions of a real measure of value. In the first place they are not natural measures. The proportion between corn and silver gives an artificial value, because the comparison is between a thing naturally useful, and a thing in itself unnecessary (81). Again, it is not a constant measure, for the value of silver fluctuates. It is worth more at one place than at another, not only from being further from the mines, but from other purely accidental causes (345). It may be worth more at present than a month or other small time hence, or it may be converted into a commodity. Vessels will be made of it if more commodities can be exchanged for it in this way than by employing the same silver by way of trade. Only one of the two precious metals is "a fit matter for money;" the other metal is only a commodity (347). The proportional value of gold and silver fluctuates as the earth and the industry of man produce more of one than of the other. The only way of pitching upon the true proportion between them is by reducing each to the amount of labor required in the mining and refining of each. The man who has the ability to hire the most labor is the richest