Politician and economist. Born in Edinburgh, the older brother of Leonard Horner (1785 - 1864), Horner was educated at the High School and University in the city. Horner attended lectures given by Dugald Stewart (1753 - 1828) on political economy and this catalysed his interest in this subject. He was admitted to the Scottish Bar in 1800 and as a Barrister in England in 1802, where he practised for some years. He served as Member of Parliament for two Cornwall constituencies; elected in St. Ives in 1806, and thereafter for St. Mawes. He was involved in shaping monetary policy and strongly opposed to the Corn Laws.
In 1802, Horner established the Edinburgh Review, a quarterly magazine, along with Henry Brougham (1778 - 1868), who had been his school contemporary, Francis Jeffrey (1773 - 1850) and Sydney Smith (1771 - 1845). It was immediately popular, setting the standard for other literary magazines which followed and its circulation grew to a remarkable 13,500 by 1818. The Review continued until 1929.
Horner was a close friend of architect William Henry Playfair (1789 - 1857).
He died in Pisa (Italy).
