Joseph Priestly (1733–1804)
Publisher Summary Joseph Priestley (1733–1804) was a notable theologian, philosopher and chemist of the Enlightenment era. He was a prominent figure in the dissenting circles of provincial England, spending significant phases of his life in Leeds and Birmingham. He entered science with a historical project on electricity, and gained international fame with his work on pneumatic chemistry. He discovered and studied many new gases including what he called dephlogisticated air, later dubbed oxygen by Lavoisier. Priestley's work on pneumatic chemistry was strongly driven by his concern about the goodness of air, and he used the phlogiston theory to help him make sense of a great variety of phenomena that he observed. Today he is often remembered as a dogmatic defender of the phlogiston theory, but on the contrary he was committed to a pluralistic and empiricist scientific method, and attacked Lavoisier's school for their dogmatism. Priestley was driven out of England for his support of the French Revolution, and died in exile in rural Pennsylvania.