Deism vs Atheism: Two Enlightenment Responses to Religion

The Enlightenment produced a wide range of positions on religious questions, from devout Christianity to radical atheism. The two most characteristic Enlightenment positions were deism, which accepted the existence of God but rejected the supernatural claims of organized religion, and atheism, which rejected the existence of God altogether. This article examines the difference between the two positions, the key thinkers associated with each, and the lasting influence of each on modern thought.

The Deist Position

Deism was the most characteristic religious position of the Enlightenment. The deist accepted the existence of God and the existence of a moral order, but rejected the special status of any particular religious revelation, the authority of any particular church, and the credibility of miracles. God, for the deist, was a kind of cosmic designer who had created the universe, set its laws in motion, and then withdrawn to let it run.

The deist position was held by many of the most important figures of the Enlightenment, including Voltaire, Benjamin Franklin, and Thomas Jefferson. The position had the advantage of being compatible with the new natural philosophy — the deist could accept the argument from design and the regular laws of nature — while rejecting the miraculous elements of traditional Christianity.

The deist position was also compatible with a strong commitment to religious toleration. If no particular church had a privileged access to truth, then all churches (and all religions) deserved equal respect. The deist commitment to religious toleration was an important source of the modern principles of religious freedom and pluralism.

The Atheist Position

The atheist position, which rejected the existence of God altogether, was a minority position in the Enlightenment, but it was a real and persistent one. The French materialists, including La Mettrie, Helvétius, and the Baron d’Holbach, developed systematic materialist accounts of human nature and the natural world that left no room for God, the soul, or the afterlife.

The most famous statement of the atheist position was d’Holbach’s System of Nature (1770), which was a comprehensive materialist account of the universe. According to d’Holbach, the natural world is a vast system of matter in motion, governed by natural laws, and there is no need to appeal to any supernatural being to explain its existence or its operations. The belief in God, in d’Holbach’s view, is the result of ignorance, fear, and the machinations of priests who use religion to maintain their power over the people.

The atheist position was controversial in the eighteenth century, and it was widely attacked by religious and political authorities. The materialist books were burned, their authors were persecuted, and the atheist position was widely considered to be a danger to public order and morality.

The Philosophical Differences

The deist and the atheist positions differ in several important philosophical respects.

The first difference concerns the existence of God. The deist accepts the existence of a Creator God, and grounds this belief in the argument from design — the apparent order and complexity of the natural world points to a divine designer. The atheist rejects this argument, and argues that the natural world can be explained in terms of natural causes, without any appeal to a divine designer.

The second difference concerns the basis of morality. The deist grounds morality in the will of God, or in the natural moral order that God has established. The atheist grounds morality in human reason, human sentiment, or the social conventions that have developed in the course of human history. The deist and the atheist can agree on the content of morality — both can be moral persons — but they disagree on the foundation of morality.

The third difference concerns the nature of the universe. The deist sees the universe as a designed system, governed by laws that reflect the wisdom of the Creator. The atheist sees the universe as a natural system, governed by laws that are the result of natural processes, not of any intelligent design. The deist and the atheist can agree on the regularities of nature, but they disagree on the source of these regularities.

The Thinkers

The deist position was held by a wide range of Enlightenment thinkers, including:

Edward Herbert of Cherbury, the founder of English deism, who developed a theory of natural religion based on five common articles.

Voltaire, the most famous representative of the French Enlightenment, who defended a form of deism that was closely connected to his campaign against religious intolerance.

Benjamin Franklin, the American founding father, who described himself as a deist throughout his life.

Thomas Jefferson, the principal author of the American Declaration of Independence, who was a committed deist throughout his life.

The atheist position was held by a smaller number of Enlightenment thinkers, including:

La Mettrie, the author of Man a Machine (1747), which argued that human beings are complex machines and that there is no need to appeal to a soul or to God to explain their operations.

Helvétius, the author of On Mind (1758), which argued that all intellectual differences are the result of education and that there is no need to appeal to innate ideas or to God to explain the human mind.

Baron d’Holbach, the author of the System of Nature (1770), which was the most comprehensive statement of the materialist and atheist position in the Enlightenment.

The Lasting Influence

The deist position has had a profound influence on the development of modern thought, especially in the English-speaking world. The American commitment to the separation of church and state, to religious freedom, and to the importance of reason in matters of religious belief draw on the central arguments of the deist tradition.

The atheist position has had a more limited influence in the immediate aftermath of the Enlightenment, but it has become increasingly important in the modern period. The contemporary defenders of secularism, of atheism, and of a naturalistic understanding of the human condition have all drawn on the work of the eighteenth-century materialists and atheists.

Further Reading

• The Stanford Encyclopedia of Philosophy (plato.stanford.edu), relevant entry
• Mark Goldie & Robert Wokler, eds., The Cambridge History of Eighteenth-Century Political Thought (2006)
• Terence Ball, Reappraising Political Theory (1995)