Smith argued against government interference like tariffs or subsidies, believing that open competition and the voluntary exchange of goods lead to a self-regulating, thriving economy.
He proposed that the real measure of a commodity's value is the amount of labor required to produce it, though this idea has since been heavily refined by later economists. The Five Books of the Treatise
Smith opens with the famous example of a pin factory to show that breaking down production into specialized tasks dramatically increases efficiency and total output.