… is from page 543 of Douglas Irwin’s essay “Adam Smith and Free Trade,” which is chapter 32 in the 2016 volume, edited by Ryan Patrick Hanley, Adam Smith: His Life, Thought, and Legacy:
As notes from his lectures at Glasgow University in the early 1760s attest, Smith was a convinced advocate of free trade from the very start of his career. Smith held that trade between nations was similar to trade between individuals. Human beings, he noted, have a natural propensity to truck, barter, and exchange goods with one other [sic]. If the exchange was voluntary, trade would not take place unless both parties were better off. And just as individuals were better off with trade, so were countries.


As notes from his lectures at Glasgow University in the early 1760s attest, Smith was a convinced advocate of free trade from the very start of his career. Smith held that trade between nations was similar to trade between individuals. Human beings, he noted, have a natural propensity to truck, barter, and exchange goods with one other [sic]. If the exchange was voluntary, trade would not take place unless both parties were better off. And just as individuals were better off with trade, so were countries.
