=Connection with Wealth.=—“Wealth consists of useful things.” “Wealth consists of valuable things.” Both statements reflect current views, and both are true, the one suggesting an Inventory, the other a Calculation of the same things. =The Problem stated.=—Twenty goods, different in substance, size, shape, quality, use, are equal in this, that a twenty-first good, say a shilling, will purchase any of them. What is it that puts them in a balance, and pronounces all the twenty-one goods equal in value? =An Indication.=—It has been suggested that Value is the order of our Preferences. But can one thing, strictly speaking, be “preferred” to another unless the two are at equal price? At any rate, it cannot be said _simpliciter_ that the ordinary man “prefers” diamonds to his dinner. The suggestion, however, reminds us that we never value anything by itself; we always value it by reference to something else. Thus, in the last resort, Value expresses an order—a more or less. =Comparison with other Measures.=—Measures do not hang in the air; they are based on something—a unit proclaimed by Governments, either quite arbitrarily or as corresponding to some presumably fixed natural phenomenon, _e.g._, the yard and the metre. So, in ancient times, the gold talent _weighed_ 120 to 140 food-grains, and was equated, by convention, to the ox, which was the primitive unit of value. But this throws no light on the _value_ measurement which equated the ox to the talent. (It is submitted, in passing, that the equation was only an ideal one—a convenient point of departure; that the ox generally exchanged for the talent with a plus or a minus, just as the point of departure for a lawyer’s fee is “six and eightpence,” or as the 30 acres presumed necessary for the support of a manorial family was the point of departure for a “virgate.”) The grain basis of the gold talent, however, suggests that the value measurement also has a natural basis;—that Value is the comparison and expression of things in a Common Third. What is this Common Third?