The leading English mathematician before Isaac Newton, born in Ashford, Kent, SE England, UK. He studied at Cambridge, and took orders, but in 1649 became professor of geometry at Oxford. His Arithmetica infinitorum (1655, The Arithmetic of Infinitesimals) was a stimulus for Newton's work on calculus and the binomial theorem. He also wrote on proportion, mechanics, grammar, logic, decipherment (he deciphered encrypted messages intercepted from Royalist supporters), theology, and the teaching of the deaf. He was one of the founders of the Royal Society.