The classical theory of international trade was formulated by Robert Torrens, David Ricardo, and John Stuart Mill. Their theory relates to comparative advantage. Ricardo's theory states that countries will export commodities where they have a comparative advantage and import commodities where they have a comparative disadvantage. Ricardo used a numerical example to illustrate how trade benefits both Portugal and England even when Portugal has an absolute advantage in both goods - by specializing in their comparative advantages, both countries can consume beyond their production possibilities.