Richard Cantillon, acknowledged by many historians as the first great economic "theorist", is an obscure character. This much is known: he was an Irishman with a Spanish name who lived in France and reputedly made a fortune of some twenty million livres under John Law's schemes before moving to England. He died in a fire in his London home - allegedly set by his discharged cook.
Cantillon's entire reputation rests on his one remarkable treatise, Essai Sur la Nature du Commerce en Général was written in French circa 1732 and published anonymously in England some twenty years after his death (some claim it was only a French translation of a lost English original). Although his work was well-known to the Physiocrats and the French school, Cantillon fell into obscurity in the English-speaking world until resurrected and popularized by William Stanley Jevons in the 1880s.
Cantillon was perhaps the first to define long-run equilibrium as the balance of flows of income, thus setting the foundations both for Physiocracy as well as Classical Political Economy. Cantillon's system was is clear and simple and absolutely path-breaking. He developed a two-sector general equilibrium system from which he obtained a theory of price (determined by costs of production) and a theory of output (determined by factor inputs and technology). He followed up on Petty's conjecture about the par of labor and land, thereby enabling him to reduce labor to the amount of necessities needed to sustain it and thus making both labor supply and output a function of the land absorption necessary to produce the necessities to feed labor and the luxuries to feed landlords. By demonstrating that relative prices are reducible to land-absorption rates, Cantillon can be said to have derived a fully-working "land theory of value". [click here for a review of Cantillon's system.]
Cantillon's careful description of a supply-and-demand mechanism for the determination of short-run market price (albeit not long-run natural price) also stand him as a progenitor of the Marginalist Revolution. In particular, his insightful notes on entrepreneurship (as a type of arbitrage) have made him a darling of the modern Austrian School. Cantillon was also one of the first (and among the clearest) articulators of the Quantity Theory of Money and attempted to provide much of the reasoning behind it.
Finally, one of the consequences of his theory was that he arrived at a quasi-Mercantilist policy conclusion for a favorable balance of trade but with a twist: Cantillon recommended the importation of "land-based products" and the exporting of "non-land-based" products as a way of increasing national wealth.
Major Works of Richard Cantillon
Resources on Cantillon