Joseph Priestley: materialism and the science of the mind. Foundations, controversies, reception

This special issue deals with key aspects of the philosophy of Joseph Priestley (1733–1804). Priestley is known to the general public primarily for his discovery of oxygen, and he is mostly acknowledged within the history of science, and more broadly as a prominent Unitarian theologian. His main occupation and education was indeed that of a theologian and a minister. Much less attention has been devoted to Priestley's distinctly philosophical writings, most of which came out during the 1770s while he was working for Lord Shelburne (William Petty, 1737–1805) between 1772 and 1780.¹ This is striking because he elaborated and defended an ambitious materialist and determinist philosophy during this period that was based on an equally elaborate theory of matter. The papers presented in this special issue are intended to contribute to a more detailed understanding of Priestley's philosophy itself, and its impact.

In spite of its thematic breadth and contemporary influence also on the Continent, Priestley's philosophy, and his materialism in particular, are mostly treated in survey works or in otherwise summary texts. For instance, a recent volume covering Priestley's accomplishments in general includes just one contribution out of seven dealing with his metaphysics.² Similarly, older scholarship tends to give broad overviews.³ There are a few notable exceptions: Yolton devotes a chapter to Priestley's materialism in particular, Tapper to the development of his materialism; Harris discusses Priestley's determinism in detail, Garret and Tapper his engagement with common sense philosophy, and Mudroch his views on causality.⁴ Also, Sakkas discusses Priestley within the context of Jonathan Israel's conception of Radical Enlightenment, and McEvoy and Eshet deal with philosophical issues in relation to Priestley's scientific work.⁵ The most detailed treatment of Priestley's philosophy available is part of the unfortunately unpublished dissertation by Mills.⁶ There is, furthermore, no modern edition of Priestley's works except for a few political writings.⁷ Similarly, the field of early modern materialism has undergone something of a renaissance in recent Anglophone scholarship,⁸ but, despite the singular way in which Priestley proclaims his materialism – almost alone in the English-speaking world, and in ways quite different from those of La Mettrie or d’Holbach (or Hobbes, who did not use the term) – he is also quite absent therein.

The dimension of Priestley's philosophical project is forcefully expressed on the final pages of the Disquisitions relating to Matter and Spirit, arguably his most important work in philosophy, in which he summarizes it as follows:

In short, it is my persuasion, that the three doctrines of materialism, of that which is commonly called Socinianism, and of philosophical necessity, are equally parts of one system, being equally founded on just observations of nature, and fair deductions from the scriptures.⁹

Thus, Priestley aims at establishing a philosophical “system” that entails three interrelated aspects – materialism, Socinianism, and determinism – and has two equal but quite different sources: observation of nature and the Holy Scriptures. Materialism, to name one example of their interrelation, also serves as a foundation of Socinianism: denying the doctrine of trinity and the pre-existence of Jesus Christ belongs to the core of Socinian teachings, and, along these lines, Priestley argues that materialism “is conclusive against the doctrine of a soul, and consequently against the whole system of pre-existence,”¹⁰ i.e. the pre-existence of Christ. If Jesus Christ is a human being, and human beings do not have a soul distinct from the body, it is difficult to see in which way he would have pre-existed.

Priestley’s more narrowly philosophical writings can be grouped into four sets. (1) Hartley's Theory of the Human Mind (in particular the “Introductory Essays” Priestley added) and the Disquisitions relating to Matter and Spirit are the chief works for his materialism, including his views on the brain, on association psychology, and on the theory of matter. (2) An Examination of Dr. Reid's Inquiry into the Human Mind is Priestley's discussion of Scottish common sense philosophy, partly in relation to association psychology. (3) Priestley elaborated a compatibilist theory of freedom in The Doctrine of Philosophical Necessity and published works in defense of this doctrine (and also his materialism): A Free Discussion of the Doctrines of Materialism, and Philosophical Necessity, A Letter to the Rev. Mr. John Palmer, in Defence of the Illustrations of Philosophical Necessity, A Second Letter to the Rev. Mr. John Palmer and A Letter to Jacob Bryant Esq. in Defence of Philosophical Necessity. (4) At the intersection to his more specifically theological writings, Priestley defends religion, in particular the argument from design, against other philosophers such as David Hume and Baron d’Holbach in a series of books: Letters to a Philosophical Unbeliever (1780–1795) and Additional Letters to a Philosophical Unbeliever. There are several works elaborating on Socinian/Unitarian themes, such as the Institutes of natural and revealed religion, A History of the Corruptions of Christianity, and An History of Early Opinions concerning Jesus Christ.

The papers included in this special issue cover the three aspects of Priestley's philosophical “system”, i.e. Socinianism, materialism, and determinism, as well as his discussion of competing philosophical views and the reception of his philosophy. Sascha Salatowsky, in “Unitarian Materialism. Christoph Stegmann, Joseph Priestley, and their Concepts of Matter and Soul,” examines the affinities between Priestley's materialism and that of the Socinian Christoph Stegmann (in relation to whom Leibniz spoke of a specifically Socinian kind of philosophy). Charles T. Wolfe, in “From the logic of ideas to active-matter materialism: Priestley's Lockean problem and early neurophilosophy,” deals with the empiricist basis of Priestley's materialism and its complex relation to Locke's epistemology, including in the way it integrates a “cerebral” dimension, which Locke sought to avoid. Falk Wunderlich, in “Priestley on materialism and the essence of God,” addresses the different views Priestley addresses concerning whether we are altogether ignorant of the essence of God or whether God might be material in spite of our ignorance of real essences. Alan Tapper, in “Joseph Priestley and the Argument from Design,” deals with Priestley's defense of the argument from design against David Hume, Matthew Turner, and Erasmus Darwin. Sebastiano Gino, in “Scottish Common Sense, Association of Ideas and Free Will,” addresses the version of determinism Priestley proposed and defended against Thomas Reid's libertarianism. Pascal Taranto, in “Joseph Priestley as an Heir of Newton,” examines Priestley's accommodation of Isaac Newton's methodological “rules of philosophizing.” The papers by Paola Rumore (“Priestley in Germany”) and Udo Thiel (“Priestley and Kant on Materialism”) are both devoted to the reception of Priestley's materialism in contemporary German philosophy, affirmatively by German materialists (Rumore) and critically by Kant (Thiel), which proves to be highly influential but has not been studied so far.

We hope that this special issue on Priestley's materialism (in and out of context) contributes to stimulate discussion of Priestley, a major figure in different disciplines who might deserve more philosophical consideration, as well as of issues raised by Priestley and in his wake, such as the relation between materialism and Christianity, the materialist appropriation of empiricism, and, of course, broader, transversal themes like Socinianism, compatibilism, and Newtonianism. We are also grateful to Stephen Gaukroger for his interest in this project, and to the staff of Intellectual History Review and Taylor & Francis, particularly Julie Weston, for their timely and efficient support.

ORCID

Charles T. Wolfe http://orcid.org/0000-0002-7956-9085

Notes on contributors

Charles T. Wolfe is an Assistant Professor (ricercatore) in the Dipartimento di Filosofia e Bene Culturali, Università Ca'Foscari, Venice. He works primarily in history and philosophy of the early modern life sciences, with a particular interest in materialism and vitalism. Recent books: Materialism: A Historico-Philosophical Introduction (Springer, 2016) and La philosophie de la biologie: une histoire du vitalisme (Classiques Garnier, 2019); edited volumes include Monsters and Philosophy (2005), The Body as Object and Instrument of Knowledge (2010, with O. Gal), Vitalism and the scientific image in post-Enlightenment life-science (2013, with S. Normandin), Brain Theory (2014), and Philosophy of Biology before Biology (w. C. Bognon-Küss, 2019). He is co-editor of the book series ‘History, Philosophy and Theory of the Life Sciences’ (Springer). Papers available at [https://unive.academia.edu/CharlesWolfe]

Falk Wunderlich teaches philosophy at Martin-Luther-Universität Halle-Wittenberg. He is is the author of Kant und die Bewußtseinstheorien des 18. Jahrhunderts (2005) and has recently edited the special issue Varieties of Early Modern Materialism of the British Journal for the History of Philosophy (vol. 24.5, 2016, with Patricia Springborg) and Kant and his German Contemporaries (2018, with Corey W. Dyck).

Notes

1 Schofield, The Enlightened Joseph Priestley, 141–3.

2 Dybikowski, “Joseph Priestley, Metaphysician and Philosopher of Religion.”

3 Hiebert, “The Integration of Revealed Religion and Scientific Materialism in the Thought of Joseph Priestley”; Schofield, “Joseph Priestley: Theology, Physics, and Metaphysics”; Schwartz and McEvoy (eds), Motion Toward Perfection.

4 Yolton, Thinking Matter, 107–26; Harris, Of Liberty and Necessity, 167–78; Garrett, “In Defense of Elephants: Priestley on Reid on How to Be a Newtonian of the Mind”; Mudroch, “Joseph Priestley’s Eclectic Epistemology”; Tapper, “The Beginnings of Priestley’s Materialism”; Tapper, “Reid and Priestley on Method and the Mind”; see also Durner, “‘Immateriality of Matter’. Theorien der Materie bei Priestley, Kant und Schopenhauer.”

5 Israel, Democratic Enlightenment, 13; Sakkas, “Joseph Priestley on Metaphysics and Politics: Jonathan Israel’s ‘Radical Enlightenment’ Reconsidered”; McEvoy, “Gases, God and the Balance of Nature: A Commentary on Priestley's (1772) ‘Observations on Different Kinds of Air’”; Eshet, “Rereading Priestley: Science at the Intersection of Theology and Politics.”

6 Mills, “Joseph Priestley and the Intellectual Culture of Rational Dissent, 1752–1796,” 64–216.

7 The almost contemporary edition by John Towill Rutt (Theological and Miscellaneous Works of Dr. Priestley, 25 vols, London 1817–1831) had no successor, with the only exception of a few political works (Priestley, Political Writings).

8 Wolfe,“Materialism”; Wolfe, Materialism. A Historico-Philosophical Introduction; Wunderlich and Springborg, (eds), Varieties of Early Modern Materialism.

9 Disquisitions Relating to Matter and Spirit, 356.

10 History of Early Opinions, 85.