ideal scale of equal parts. If it be demanded what ought to be the standard value of one part? I answer by putting another question: What is the standard length of a degree, a minute, a second? It has none ... but so soon as one part becomes determined by the nature of a scale, all the rest must follow in proportion. Of this kind of money ... we have two examples. The bank of Amsterdam presents us with the one, the coast of Angola with the other.”53
Steuart speaks here simply of the part money plays in circulation as the standard of price and money of account. If different commodities are marked in the price-list at 15s., 20s., 36s., respectively, then I care, in fact, neither for the silver substance, nor for the name of the shilling when comparing the magnitudes of their values. The ratios between the numbers 15, 20, 36, tell everything, and the number 1 has become the only unit of measure. Only the abstract proportion of numbers can at all serve as a purely abstract expression of proportion. In order to be consistent, Steuart should have dropped not only gold and silver, but their legal baptismal names as well. Since he does not understand the nature of the transformation of the measure of value into a standard of price, he naturally believes that the definite quantity of gold which serves as a unit of measure relates as a measure not to other quantities of gold, but to values as such. Since commodities appear as quantities of the same denomination through the conversion of their exchange values into prices, he denies that property of the measure which reduces them to one denomination; and since in this comparison of different quantities of gold the quantity of gold which serves as a unit of measure is conventional, he does not see the necessity of fixing it at all. Instead of calling 1-360 part of a circle degree, he might give that name to 1-180th part; the right angle would then be measured by 45 degrees instead of 90, and acute and obtuse angles would be measured accordingly. Nevertheless, the measure of the angle would remain, then, as before, first a qualitatively definite mathematical figure, the circle, and