sented as the scientific formula of a single side of that contradiction of exchange-value. But let us put posterity altogether on one side and confront M. Proudhon with his predecessor Ricardo. Here are some passages from that author which sum up his theory of value.
"It is not utility which is the measure of exchange-value although that quality is absolutely necessary." (Vol. I., p. 3, "Principles of Political Economy.")
"Things, once they are recognised as useful in themselves, draw their exchange-value from two sources: from their scarcity and from the quantity of labor necessary to acquire them. There are some things the value of which depends only on their scarcity. No amount of labor being capable of increasing their quantity, their value cannot fall through their too great abundance. Such are rare statues, pictures, &c. This value depends solely on the faculties, the tastes and the caprice of those desirous of possessing such objects." (Vol. I., pp. 4 and 5.) "These, however, form but a very small part of the commodities which are constantly exchanged. The greater number of desirable objects being the fruit of industry, they can be multiplied, not only in one country, but in many, to an extent to which it is almost impossible to fix any limits, every time that one is willing to employ the industry necessary to create them." (Vol. I., p. 5.) "When, then, we speak of commodities, of their exchange-value, and of the principles which regulate their relative price, we have in view only those commodities the quantity of which can be increased by the industry of man, the production of which is encouraged by competition, and is not prevented by any obstacle." (Vol. I., p. 5)
Ricardo quotes Adam Smith, who, according to him, "has defined with great precision the primitive source
