«There is this difference between moral and political economy: the first terms ´useful´ only those objects that satisfy those needs explained by reason, while the second grants this name to all objects that man can desire, either in the interest of self-preser-vation, or by virtue of his passions and whims. Therefore bread is useful because they appeal to our sensuality. Water and wine are useful because they quench our thirst, and the most dangerous liquors are useful because men have a taste for them. Wool and cotton are useful because one must be clothed; pearls and diamonds are useful as objects of adornment.»

Auguste Walras: De la nature de la richesse et de l´origine de la valeur (1831), Paris: Librairie Félix Alcan, 1938, p. 82. (Vía HOW ARCHITECTURE LEARNED TO SPECULATE)