Antoine Augustin Cournot (28 August 1801 – 31 March 1877) was a French philosopher and mathematician who also made important contributions to economic theory.

In 1838 he published the book Researches on the Mathematical Principles of the Theory of Wealth in which introduced the ideas of functions and probability into economic analysis. He derived the first formula for the rule of supply and demand as a function of price and in fact was the first to draw supply and demand curves on a graph, anticipating the work of Alfred Marshall by roughly thirty years.

The Cournot duopoly model developed in his book also introduced the concept of a (pure strategy) Nash equilibrium, the reaction function and best-response dynamics, anticipating Nash by more that a century.

Link to History of Economic Thought Website