Materialism in Eighteenth-Century European Thought

Eighteenth-century materialism in a sense is an extension of the seventeenth-century mechanical philosophy that was the hallmark of the scientific revolution. The mechanical philosophy offered a worldview in which matter and the natural laws of motions were supposed to explain all phenomena. In the seventeenth century, only Thomas Hobbes (1588–1679), in Leviathan (1651) and other works, and (in a much more problematic way) Baruch Spinoza (1632–1677) went so far as to argue that the mechanical philosophy could explain all the aspects of mental life. Later in the century, such monistic views, as well as trends that were inherent in the philosophy of René Descartes (1596–1650), such as the reduction of nonhuman forms of life to automata, developed the form of materialism that was characteristic of the eighteenth century.

Despite the coherence of Hobbes's materialism, the authors who were most fundamental to the passage from seventeenth-century mechanical philosophy to eighteenth-century materialism were Isaac Newton (1642–1727) and John Locke (1632–1704). Isaac Newton was a multifaceted, iconoclastic figure. He can hardly be called a materialist in any metaphysical sense. However, the impressive results he achieved in physics gave an impulse to methodological materialism in science and well beyond. John Locke's Essay concerning Human Understanding (1690; 4th edition published in 1700) developed a sensationalist psychology, based on the idea that sense perception and mental mechanisms of reason, usually in the form of calculation and association, explain all mental life without the need to postulate any nonmaterial substance. Locke famously debated whether material things (such as rocks) could think. He concluded that God could have created thinking matter and was opposed by Bishop Edward Stillingfleet (1635–1699). Locke's position was later then taken up by Anthony Collins (1676–1729) against Samuel Clarke (1675–1729). A follower of Newton, Clarke is well known because of his controversy with Gottfried Wilhelm von Leibniz (1646–1716).

Another relevant source of ideas came from the French-based seventeenth-century movement of the libertines, or freethinkers (not meant as a compliment), who opposed religious oppression, and who, often in anonymous publications, defended the free use of reason against the suffocating Catholic Counter-Reformation. Libertines challenged religious authority in morals and politics, using ideas inspired mainly by the materialism of the ancient atomistic, Epicurean, and skeptical traditions. To this movement belong authors as different as Pierre Gassendi (1592–1655) and Cyrano de Bergerac (1619–1655). The anonymous Theophrastus redivivus, published around 1660, espoused the most radical theses of libertinism, such as atheism, materialism, and a form of ethical Epicurean hedonism.