Ludwig Lachmann (1906–1990) was a German-born member of the Austrian School of economics. He studied at the London School of Economics in the 1930s, taught at the University of Wiwatersrand in South Africa, and wrote seminal material on Austrian capital theory.
Ludwig von Mises: ". The use of money in a market economy is a praxeologically necessary fact. That gold, and not something else, is used as money is merely a historical fact and as such cannot be conceived by catallactics." - Human Action