When I say that every product is worth the products which it has cost, I mean that every product is a collective unit which, in a new form, groups a certain number of other products consumed in various quantities. Whence it follows that the products of human industry are, in relation to each other, genera and species, and that they form a series from the simple to the composite, according to the number and proportion of the elements, all equivalent to each other, which constitute each product. It matters little, for the present, that this series, as well as the equivalence of its elements, is expressed in practice more or less exactly by the equilibrium of wages and fortunes; our first business is with the relation of things, the economic law. For here, as ever, the idea first and spontaneously generates the fact, which, recognized then by the thought which has given it birth, gradually rectifies itself and conforms to its principle. Commerce, free and competitive, is but a long operation of redressal, whose object is to define more and more clearly the proportionality of values, until the civil law shall recognize it as a guide in matters concerning the condition of persons. I say, then, that Say's principle, EVERY PRODUCT IS WORTH WHAT IT COSTS, indicates a series in human production analogous to the animal and vegetable series, in which the elementary units (day's works) are regarded as equal. So that political economy affirms at its birth, but by a contradiction, what neither Plato, nor Rousseau, nor any ancient or modern publicist has thought possible,-- equality of conditions and fortunes.