Professor Carver, in a recent article in the _Quarterly Journal of Economics_,[22] insists on the conception of value as a quantity. Gabriel Tarde states the matter illuminatingly in a passage in his _Psychologie Economique_:[23]-- Value is a quality which we attribute to things, like color, but which, like color, exists only in ourselves.... This quality is of that peculiar species of qualities which present numerical degrees, and mount or descend a scale without essentially changing their nature, and hence merit the name of quantities. On the other hand, the doctrine of relativity has characterized the teachings of the English School, of the Austrians (except Wieser), and of many of the more eclectic followers of each in this country. It will appear later that this relative conception follows naturally from their individualistic method of approaching the subject. The essence of the relative conception of value, whether defined as "power in exchange," or "ratio of exchange," or, with Professor Fisher,[24] and others, as a quantity of goods to be got in exchange, comes out in the statement, so common in the text-books, that, while there can be a general rise or fall of _prices_, there cannot be a general rise or fall of _values_, since a rise in the value of one good implies a corresponding fall in the value of all other goods. The incompatibility of the two opposing conceptions comes out strikingly here: if value be an absolute magnitude, then there _can_ be a general rise or fall of values without disturbing exchange ratios at all--12:6::6:3. All values might be cut in half, or multiplied by any factor, and, provided all decreased or increased in the same degree, exchange relations would not change. Now this difference is fundamental. Vastly more than terminology and definition is involved. Is value a quantity or a relation? Is value a thing which determines causally exchange relations, or is value determined causally by them? To the writer, the former conception seems a logical necessity. Value as merely relative is a thing hanging in the air. There is a vicious circle in reasoning if, when I ask you what the value of wheat is, you refer me to corn, and then when I ask you the value of corn, you refer me again to wheat. And if you put in intermediate links, even as many links as there are different commodities in the market, the circle still remains: the value of A is its power over, or its ratio with, B; the value of B its relation to C; the value of C ... its relation to Z; and the value of Z, the last in the series, must come back to its relation to one of those named before. This circle is noted and sharply criticized by Wieser:[25]--