Richard Price (23 February 1723 19 April 1791) was a Welsh moral philosopher, Nonconformist minister and mathematician. He was also a political reformer, pamphleteer, active in radical, republican, and liberal causes such as the French and American Revolutions. He was well-connected and fostered communication between many people, including Thomas Jefferson, John Adams, George Washington, Mirabeau and the Marquis de Condorcet. According to the historian John Davies, Price was “the greatest Welsh thinker of all time”.Born in Llangeinor, near Bridgend, Wales, Price spent most of his adult life as minister of Newington Green Unitarian Church, on the then outskirts of London, England. He edited, published and developed the BayesPrice theorem and the field of actuarial science. He also wrote on issues of demography and finance, and was a Fellow of the Royal Society.