page_title: Joseph Priestley and Dissent
section_title: Materialist philosopher and theologian
hierarchical_section_title: Joseph Priestley and Dissent / Materialist philosopher and theologian
caption_attribution_description: Title page to Disquisitions on Matter and Spirit by Joseph Priestley
context_page_description: Joseph Priestley was a British natural philosopher, political theorist, clergyman, theologian, and educator. He was one of the most influential Dissenters of the late 18th-century.
  A member of marginalized religious groups throughout his life and a proponent of what was called "rational Dissent", Priestley advocated religious toleration, helped Theophilus Lindsey found the Unitarian church and promoted the repeal of the Test and Corporation Acts in the 1780s. As the foremost British expounder of providentialism, he argued for extensive civil rights, believing that individuals could bring about progress and eventually the Millennium. Priestley's religious beliefs were integral to his metaphysics as well as his politics and he was the first philosopher to "attempt to combine theism, materialism, and determinism," a project that has been called "audacious and original."
context_section_description: In a series of five major metaphysical works, all written between 1774 and 1778, Priestley laid out his materialist view of the world and tried "to defend Christianity by making its metaphysical framework more intelligible," even though such a position "entailed denial of free will and the soul." The first major work to address these issues was The Examination of Dr. Reid's Inquiry ... Dr. Beattie's Essay ... and Dr. Oswald's Appeal (1774). He challenged Scottish common-sense philosophy, which claimed that "common sense" trumped reason in matters of religion. Relying on Locke and Hartley's associationism, he argued strenuously against Reid's theory of mind and maintained that ideas did not have to resemble their referents in the world; ideas for Priestley were not pictures in the mind but rather causal associations. From these arguments, Priestley concluded that "ideas and objects must be of the same substance," a radically materialist view at the time. The book was popular and readers of all persuasions read it. Charles Lamb wrote to Samuel Taylor Coleridge, recommending "that clear, strong, humorous, most entertaining piece of reasoning" and Priestley heard rumors that even Hume had read the work and "declared that the manner of the work was proper, as the argument was unanswerable."
  When arguing for materialism in his Examination Priestley strongly suggested that there was no mind-body duality. Such opinions shocked and angered many of his readers and reviewers who believed that for the soul to exist, there had to be a mind-body duality. In order to clarify his position he wrote Disquisitions relating to Matter and Spirit (1777), which claimed that both "matter" and "force" are active, and therefore that objects in the world and the mind must be made of the same substance. Priestley also argued that discussing the soul was impossible because it is made of a divine substance and humanity cannot gain access to the divine. He therefore denied the materialism of the soul while simultaneously claiming its existence. Although he buttressed his arguments with familiar scholarship and ancient authorities, including scripture, he was labeled an atheist. At least a dozen hostile refutations of the work were published by 1782.
  Priestley continued this series of arguments in The Doctrine of Philosophical Necessity Illustrated (1777); the text was designed as an "appendix" to the Disquisitions and "suggests that materialism and determinism are mutually supporting." Priestley explicitly stated that humans had no free will: "all things, past, present, and to come, are precisely what the Author of nature really intended them to be, and has made provision for." His notion of "philosophical necessity," which he was the first to claim was consonant with Christianity, at times resembles absolute determinism; it is based on his understanding of the natural world and theology: like the rest of nature, man's mind is subject to the laws of causation, but because a benevolent God has created these laws, Priestley argued, the world as a whole will eventually be perfected. He argued that the associations made in a person's mind were a necessary product of their lived experience because Hartley's theory of associationism was analogous to natural laws such as gravity. Priestley  contends that his necessarianism can be distinguished from fatalism and predestination because it relies on natural law. Isaac Kramnick points out the paradox of Priestley's positions: as a reformer, he argued that political change was essential to human happiness and urged his readers to participate, but he also claimed in works such as Philosophical Necessity that humans have no free will. Philosophical Necessity influenced the 19th-century utilitarians John Stuart Mill and Herbert Spencer, who were drawn to its determinism. Immanuel Kant, entranced by Priestley's determinism but repelled by his reliance on observed reality, created a transcendental version of determinism that he claimed allowed liberty to the mind and soul.
  In the last of his important books on metaphy
caption: Title page from the first edition of Disquisitions relating to Matter and Spirit (1777)
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