The Wealth of Nations expected to fetch £50,000 at auction in Edinburgh A rare first edition of one of the Scottish Enlightenment's most influential books is expected to fetch up to £50,000 when it goes under the hammer next week. Adam Smith's The Wealth of Nations, published in 1776, is widely considered to be the founding work of modern economics and revolutionised the understanding of world trade. Edinburgh-based auctioneers Lyon & Turnbull estimate the first edition will go for between £30,000 and £50,000 when it goes up for sale on September 4. Smith spent ten years writing his magnum opus at his home in Kirkcaldy, drawing on his extensive knowledge of politics, economics and moral philosophy. He enrolled at Glasgow University as a 14-year-old and made his name delivering public lectures at Edinburgh University on the subject of "the progress of opulence." In 1750 he met fellow Scottish philosopher David Hume and the two became close friends, sharing ideas across a range of subjects including history, politics and religion. The following year Smith took a professorship at Glasgow University, a position that enabled him to travel widely across Europe. After publishing The Theory of Moral Sentiments in 1759, he dedicated himself to The Wealth of Nations, in which he argued that free trade enriched both sides and established the principle of measuring nations" wealth in terms of their output rather than their possessions. Simon Vickers, book specialist at auctioneers Lyon & Turnbull, said: "Smith challenged the prevailing mercantilist economic philosophy, in which people saw national wealth in terms of a country's stock of gold and silver and imports as a danger to a nation's wealth, arguing that in a free exchange both sides became better off. Quite simply, nobody would trade if they expected to lose from it. The buyer profits, he argued, just as the seller does. Imports are just as valuable to us as our exports are to others. Because trade benefits both sides, Smith argued, it increases our prosperity just as surely as do agriculture or manufacture. A nation's wealth is not the quantity of gold and silver in its vaults, but the total of its production and commerce - what today we would call gross national product. Other lots in the sale include a signed third edition of Harry Potter and the Philosopher's Stone, estimated at between £200 and £250, and a first edition of Robert Louis Stevenson's Dr Jekyll and Mr Hyde, valued at £300 to £400.