The Importance and Extent of Free Inquiry in Matters of Religion – Joseph Priestley

Overview

The Importance and Extent of Free Inquiry in Matters of Religion is a sermon by Joseph Priestley (1733–1804), the English Rational Dissenting minister, theologian, educator, political writer, and natural philosopher best known to the wider public for his experimental work on gases, including the isolation of what came to be called oxygen. The work belongs to Priestley’s extensive body of theological and controversial writing rather than to his scientific output. It was delivered and published as a sermon to Protestant Dissenting congregations in Birmingham, where Priestley served as a minister after settling there in 1780 and where he was associated with the circle of natural philosophers and manufacturers known as the Lunar Society.

The sermon was preached on 5 November — the anniversary of the Gunpowder Plot, a date traditionally marked in England with sermons touching on questions of religion, liberty, and the dangers of persecution. This occasion is central to the work’s later notoriety, because in developing his argument Priestley used an image of “laying gunpowder, grain by grain, under the old building of error and superstition,” which he expected reasoned inquiry gradually to undermine and eventually to overthrow. The metaphor, intended to describe the peaceful triumph of truth over religious corruption and superstition, was afterward turned against him by his opponents, and it contributed to his popular nickname “Gunpowder Joe.”

Argument and Themes

The sermon expresses convictions that run throughout Priestley’s theological work. He held that religious truth is best served, not endangered, by unrestricted examination; that no doctrine should be shielded from criticism by authority, tradition, or the power of the state; and that error and superstition survive only because inquiry is suppressed. Free inquiry, on this view, is both a right and a duty of every Christian, and its extent should be unlimited, reaching even doctrines long treated as sacred and untouchable.

Underlying this was Priestley’s characteristic optimism about the progress of knowledge. He believed that open discussion would strip away what he regarded as the accumulated corruptions of Christianity and leave a purified, rational, and (in his terms) primitive faith. This connects the sermon closely to his larger theological project, expressed in works such as his history of the corruptions of Christianity, in which he argued that many established doctrines were later accretions rather than authentic elements of early Christian teaching. Priestley was a leading exponent of Unitarian and materialist positions within Rational Dissent, and his confidence that reason would demolish inherited orthodoxy — including doctrines he rejected — animates the sermon’s insistence that inquiry must be both important and unbounded.

The gunpowder image served this argument: the “explosion” Priestley envisaged was intellectual and religious, the collapse of an “edifice” of error built up over ages, brought down by the slow, cumulative work of free examination rather than by violence. In its original setting the figure was a metaphor for the irresistible advance of truth, not a call to physical destruction.

Context and Reception

Priestley wrote and preached at a time of intense controversy over the position of Protestant Dissenters in England, including the campaign to repeal the Test and Corporation Acts, which excluded non-Anglicans from full civil participation. His polemical confidence, his heterodox theology, and his sympathy with movements for political and religious reform made him a prominent and divisive figure. Conservative churchmen and loyalists regarded his combination of religious heterodoxy and reformist politics as a threat to the established order in both church and state.

In this charged atmosphere the “gunpowder” passage proved damaging. Opponents quoted it to portray Priestley as an enemy bent on destroying the Church of England, and the image fed the hostility that culminated in the Birmingham (Priestley) Riots of 1791, during which mobs attacked and destroyed his house, library, and laboratory, along with Dissenting meeting houses and the property of other reformers. Priestley subsequently left Birmingham and, some years later, emigrated to the United States, where he spent the last part of his life.

Significance

Within Priestley’s writings the sermon is a compact and vivid statement of his lifelong principle that religion has nothing to fear and everything to gain from complete freedom of inquiry. It exemplifies the outlook of eighteenth-century Rational Dissent: the union of Enlightenment confidence in reason and progress with a reforming, anti-authoritarian understanding of Christianity. Its historical importance, however, lies as much in its afterlife as in its arguments. The gunpowder metaphor became one of the most frequently cited phrases associated with Priestley, shaping his public reputation, supplying ammunition to his enemies, and forming part of the background to one of the most notorious episodes of anti-Dissenter violence in Georgian England.