Joseph Priestley 1733 – 1804

Joseph Priestley was an English natural philosopher, theologian, and political theorist, and one of the founding figures of English Unitarianism. Best known to the history of science as the discoverer of oxygen and several other gases, he was equally significant as a defender of civil and religious liberty in support of the American and French Revolutions. His Birmingham house and laboratory were destroyed by a Church-and-King mob in 1791, and he emigrated three years later to Pennsylvania, where he lived out his last decade. His Institutes of Natural and Revealed Religion and Essay on the First Principles of Government shaped early liberal political thought.

Joseph Priestley was born at Birstall Fieldhead in Yorkshire in March 1733 into a family of Calvinist Dissenters. Refused an English university because of his nonconformity, he was educated at the Daventry Academy and ministered successively at Needham Market and Nantwich before joining the Warrington Academy in 1761 as tutor in languages and belles lettres. He served as minister at Mill Hill Chapel in Leeds (1767–1773), as librarian and companion to Lord Shelburne (1773–1780), and as minister of New Meeting in Birmingham (1780–1791), where he joined the Lunar Society of Erasmus Darwin, James Watt, Matthew Boulton, and Josiah Wedgwood.

His scientific writings include The History and Present State of Electricity (1767), Experiments and Observations on Different Kinds of Air (1774–1786), and the announcement of the gas later named oxygen (1774); his religious and political works include An Essay on the First Principles of Government (1768), Institutes of Natural and Revealed Religion (1772–1774), the Disquisitions Relating to Matter and Spirit and The Doctrine of Philosophical Necessity (both 1777), and the History of the Corruptions of Christianity (1782).

Priestley defended a materialist necessitarianism, a unitarian Christology stripped of the 'corruptions' of the early councils, and a utilitarian liberalism that took 'the good and happiness of the members, that is, the majority' as the criterion of government. The Birmingham riots of 1791, incited by his sympathy for the French Revolution, destroyed his house and laboratory; he emigrated to Pennsylvania in 1794 and died at Northumberland in February 1804.