Thus e. g., Adam Smith says: “Equal quantities of labour, at all times and places, may be said to be of equal value to the labourer. In his ordinary state of health, strength and spirits, in the ordinary degree of his skill and dexterity, he must always lay down the same portion of his ease, his liberty, and his happiness. The price which he pays must always be the same, whatever may be the quantity of goods which he receives in return for it. Of these, indeed, it may sometimes purchase a greater and sometimes a smaller quantity; but it is their value which varies, not that of the labour which purchases them.... Labour alone, therefore, never varying in its own value ... is their [commodities’] real price, etc. Adam Smith (Book I., ch. V., p. 34, Oxford, 1869. Translator.)

David Ricardo, “On the Principles of Political Economy and Taxation,” 3rd edition, London, 1821, p. 3.

Sismondi, “Etudes sur l’Economie Politique,” t. II., Bruxelles, 1837. “C’est l’opposition entre la valeur usuelle ... et la valeur échangeable à laquelle le commerce a reduit toute chose,” p. 161. [Paris edition, p. 229, Transl.]

Sismondi l. c., p. 163-166 seq. [Paris edition, 230 etf. Transl.]

Perhaps the silliest to be found are the annotations of J. B. Say to the French translation of Ricardo, made by Constancio, and the most pedantically arrogant are the remarks of Mr. MacLeod in his newly published “Theory of Exchange,” London, 1858.