The resolution of objects and nature as awhole into facts stated exclusively in terms of quantities which may be handled in calculation, such as saying that red is such anumber of changes while green is another, seems strange and puzzling only when we fail to appreciate what it signifies. In reality, it is adeclaration that this is the effective way to think things j the effective mode in which to frame ideas of them, to formu- late their meanings. The procedure does not vary in principle from that by which it is stated that an article is worth so many dollars and cents. The latter statement does not say that the article is literally or in its ultimate "reality" so many dollars and cents jit says that for purpose of exchange that is the way to think of it, to judge it. It has many other mean- ings and these others are usually more important inherently. But with respect to trade, it is what it is worth, what it will sell for, and the price value put upon it expresses the relation it bears to other things in exchange. The advantage in stating its worth in terms of an abstract measure of exchange such as money, instead of in terms of the amount of corn, potatoes or some other special thing it will exchange for, is that the latter method is restricted and the former generalized.