St. Thomas Aquinas, Capitalist

In today’s New York Times review of Rodney Stark’s book Victory of Reason, which asserts that historical Christianity helped the development of capitalism far more than it hindered the same, William Grimes (the reviewer) offers this tasty example:

Christian theology, which Mr. Stark praises as constantly evolving, kept pace with economic developments. Thinkers like Augustine and Thomas Aquinas gave their sanction to private property, profit and interest. In the 13th century, Albertus Magnus wrote that a just price was simply what “goods are worth according to the estimation of the market at the time of sale.”

Aquinas imagined the case of a grain merchant arriving in a country beset by famine, who knows that a convoy of other grain merchants will shortly arrive. Is he morally obliged to reveal that fact, and thereby put downward pressure on the price of his own grain? In a conclusion worthy of Adam Smith, Aquinas decided that he was not.