Portrait of William Paley (July 1743 - 25 May 1805); stippled engraving published by Joshua Belcher 1810 as frontis to 'The Works of William Paley' Volume I, prepared and with later hand colouring after contemporary 1789 painting by George Romney. Paley is best remembered today for his use of the watchmaker analogy to open his 1802 last book, 'Natural Theology'. In it he claims that complex design requires a designer, and hence animal creation requires a God. In this he followed a long tradition of British thought that can be traced to John Ray and before. This book's lucid and reasoned style of argument greatly impressed Darwin as a student in Cambridge (he occupied the same rooms as Paley once did in Christ's College). Darwin would later find fault in Paley's argument, providing an alternative agent of complex design in natural selection (Richard Dawkins so called 'Blind Watchmaker').