This brings us to _Price_. Price is Value reckoned in money; and this is the only difference in the meaning of the two terms. When one valuable is sold against another, even when one of the two is money, each is the _Value_ of the other: Value is the general and universal term in Economics. When any other valuable is sold against money, the amount of money it buys is called its _Price_: Price is a specific and restricted term in Economics. Since we shall study Money thoroughly in a later chapter, and there explain the origin and extent of its functions throughout, it is only in order to remark here, that it is for convenience' sake, that is, to make easy the comparison of valuables one with another, that Value in commerce is commonly reduced to Price. Money becomes a sort of measure, by means of which to compare all other valuables with each other. In order to ascertain the Price of a Valuable, it only needs to be sold once against money; but in order to ascertain the Value of a Valuable, it would need to be sold once against all other valuables whatsoever. This last is clearly impracticable; and so Value for practical purposes is reduced to Price. The General is made Particular for convenience. Hence we have "Prices current," but never Values current. Now it will be plain to all, how there may easily be and often is a general rise or fall of Prices while a rise or fall of Values is impossible. Price is a relative word as much as Value is, but it does not relate to so many things. Price is specific, and Value universal. Both equally involve buying and selling, but one sale of a single valuable against money leads to Price, while ten thousand sales of the same valuable against other than money would not conduct to complete Value. That would require a sale of this valuable against all other valuables in the world, and a complete statement of the comparative results.