AP European History

## Learning Outcomes

- Understand how Enlightenment thinkers applied reason to religion in the **eighteenth century**
- Identify the differences between **deism**, **skepticism**, and **atheism**
- Explain how these ideas contributed to **secularization** without making Europe simply irreligious
- Recall key thinkers including **Voltaire**, **David Hume**, **Denis Diderot**, **Pierre Bayle**, and **Baron d'Holbach**
- Analyse how criticism of religion connected to wider challenges to Old Regime authority
- Use this topic in AP European History answers focused on causation, comparison, and continuity and change

## AP European History Syllabus

For the AP European History, you are expected to understand how Enlightenment thought challenged traditional religion and helped spread new religious outlooks, with a focus on the following syllabus points:

- Know that the Enlightenment applied **reason**, **empiricism**, and **skepticism** to religion
- Identify the difference between **deism** and **atheism**
- Explain how **skepticism** questioned miracles, revelation, and church authority without always rejecting God
- Understand that **Voltaire** is best used as an example of deism, anti-clericalism, and toleration rather than atheism
- Understand that **David Hume** is best used as a skeptical critic of miracles and revealed religion
- Know that **atheism** was a more radical and less common position than deism or skepticism
- Explain how these trends encouraged **secularization** and weakened the monopoly of established churches over knowledge
- Recognise that not all Enlightenment thinkers rejected Christianity, since some pursued a **Christian Enlightenment** that tried to reconcile faith and reason

## Test Your Knowledge

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, look more closely at that area during your revision._

1. What is the difference between deism and atheism?
2. Why is David Hume usually classified as a skeptic rather than simply an atheist?
3. How did Enlightenment criticism of religion contribute to secularization?
4. Why is Voltaire not best described as an atheist?
5. How could the Enlightenment challenge church authority while still leaving room for religious belief?

## Introduction

In **AP European History Unit 4**, the Enlightenment is not just about politics and science. It is also about religion. Eighteenth-century thinkers began asking whether religious truth should be accepted because of tradition and church authority, or tested by **reason**, evidence, and observation. That shift produced several different responses: some thinkers kept belief in God but rejected miracles and church dogma; some doubted whether religious claims could ever be proved; a smaller number moved toward outright unbelief.

This matters for the exam because students often flatten the topic into a simple claim that “the Enlightenment was anti-religious.” That is too crude. The more accurate AP argument is that Enlightenment thought created a **spectrum** of belief, from moderate religious reform to deism, skepticism, and in a more radical minority, atheism and materialism.

> **Key Term: secularization**
> The growing tendency to discuss intellectual, social, and political questions in less explicitly religious terms.

### Why religion came under Enlightenment criticism

The Enlightenment grew out of earlier changes in European thought, especially the **Scientific Revolution** of the seventeenth century. Once thinkers saw that nature could be studied through observation, testing, and logical explanation, many began asking whether religion should also face rational examination. If scientists could question old ideas about the cosmos, philosophes could question old ideas about miracles, revelation, and church authority.

This was also tied to AP themes such as **Objective Knowledge and Subjective Visions** and **States and Other Institutions of Power**. Churches in the Old Regime were not only spiritual bodies. They were powerful institutions with wealth, censorship powers, legal privileges, and political influence. So criticism of religion was often also criticism of authority.

> **Key Term: philosophes**
> Enlightenment thinkers, especially associated with France, who used reason and criticism to examine society, politics, and religion.

The spread of these ideas depended on new forms of communication. Print culture made it easier to circulate pamphlets and books. Salons gave thinkers a place to discuss ideas outside direct church control. Diderot’s **Encyclopédie**, whose first volume appeared in **1751**, helped present knowledge as something to be organised by human inquiry rather than guarded by clerical authority.

Students should also link this to a cause-and-effect chain:

- Scientific success increased confidence in reason
- Reason was applied to religion
- Traditional doctrines were questioned
- Church authority weakened in intellectual life
- Secularization advanced

That does not mean religion disappeared. It means religion no longer held unquestioned control over every major issue.

> **Key Term: anti-clericalism**
> Opposition to the power, privileges, or influence of clergy and established churches.

A key distinction students miss is that anti-clericalism is not the same as atheism. A person could believe in God and still attack priests, bishops, and church corruption. In fact, many Enlightenment thinkers did exactly that.

> **Test Tip:** In SAQs and LEQs, avoid saying “Enlightenment thinkers were atheists.” A safer and stronger claim is that many criticized organized religion and clerical privilege, while only a minority embraced outright atheism.

### The spectrum from deism to skepticism to atheism

The safest way to organise this subtopic is as a spectrum.

At the moderate end stood **deists**. They believed in a rational creator God, but not in constant divine intervention through miracles or revelation. In the middle stood **skeptics**, who doubted whether claims about miracles or revealed religion could be proved with certainty. At the radical end stood a smaller group of **atheists** and **materialists**, who denied divine action or even denied God’s existence entirely.

> **Key Term: deism**
> The belief in a rational creator God knowable through reason and nature rather than through miracles, revelation, or church authority.

Deism tried to make religion fit the intellectual climate shaped by science. If the universe seemed to operate according to natural laws, then perhaps God designed those laws and then did not interfere with them. This is why the textbook identifies **Voltaire (1694–1778)** as a deist. He attacked intolerance, superstition, and the Catholic Church’s abuses, but he did not simply reject God.

Voltaire is especially useful for exam writing because he shows the moderate religious criticism of the Enlightenment. His famous slogan, _Écrasez l'infame!_ attacked what he saw as oppression and fanaticism in organized religion. But he still believed in a creator. So if a multiple-choice question asks who best represents deism, Voltaire is usually the safest choice.

The **Jean Calas** affair is a strong example of how Enlightenment religious criticism worked in practice. Calas, a French Protestant, was executed in **1762** after being falsely accused of murdering his son. Voltaire used the case to attack judicial cruelty and religious intolerance. His **Treatise on Toleration** turned a single injustice into a broader argument: if religious dogma drives persecution, then a more tolerant and rational society is needed.

> **Key Term: religious toleration**
> The principle that people of different faiths should be allowed to worship without persecution by the state.

Deism often supported toleration because deists argued that true religion was simple, rational, and moral. If that was the case, then coercion by churches or states made little sense. Belief should be guided by conscience and reason, not force.

But skepticism went further than deism in one important way. Skeptics often questioned whether humans could prove religious truth claims at all.

> **Key Term: skepticism**
> The habit of doubting inherited claims and demanding rational or empirical justification for them.

**Pierre Bayle** was an early important figure here. He argued that a moral society did not require religious uniformity. That was a major challenge to the older assumption that one faith, enforced by the state, was necessary for public order. Bayle did not simply preach unbelief. Instead, he used doubt to weaken claims of absolute certainty. That is a very Enlightenment move.

The strongest AP example of skepticism is **David Hume (1711–1776)**. The Scottish Enlightenment made Scotland a major center of new thought, and Hume became one of its leading figures. In **An Enquiry concerning Human Understanding (1748)**, especially the section “Of Miracles,” Hume argued that miracle claims rely on testimony, and testimony is weaker than consistent experience of natural law. In simple terms: if a miracle claim contradicts everything we normally know about how nature works, then reason tells us to doubt the claim before accepting it.

This is why Hume is best classified for AP as a skeptic, not simply a deist or atheist. His real importance lies in method. He asked what counts as evidence. He treated religion like any other claim that should be tested.

That mattered because Christianity relied heavily on revealed truths and miracles. Hume did not just insult religion. He challenged the standards by which religious truth was defended.

> **Test Tip:** If an essay asks how Enlightenment thought challenged religion, pair **Voltaire** with **Hume**. Voltaire shows anti-clerical deism and toleration; Hume shows skeptical criticism of miracles and revealed religion.

### Radical Enlightenment and the limits of unbelief

A smaller group moved beyond deism and skepticism into more radical unbelief.

> **Key Term: atheism**
> Disbelief in God.
>
> **Key Term: materialism**
> The view that reality is fundamentally matter governed by natural laws, often linked to radical Enlightenment thought.

The clearest AP example here is **Baron d’Holbach**. In **The System of Nature (1770)**, he presented a universe governed by matter and natural laws rather than divine action. This was much more radical than Voltaire. A deist still believed in God; d’Holbach did not see God as necessary at all.

**Denis Diderot** should be handled more carefully. He is always safe as editor of the **Encyclopédie** and as a major figure in spreading secular inquiry. He can also be associated with more radical criticism of religion, but students should be cautious about turning him into the main AP example of atheism. Diderot is better used to show dissemination of critical and secular thought.

Atheism remained a minority position because openly denying God was dangerous and socially shocking in much of eighteenth-century Europe. That is why AP essays should stress spread in unequal ways:

- **Deism** spread broadly among educated elites
- **Skepticism** became influential in intellectual debate
- **Atheism** existed, but as a more radical minority

This is a classic place to show complexity. The Enlightenment did not simply replace Christianity with atheism. Instead, it loosened the hold of established churches and widened the range of positions people could hold.

### What these ideas changed in Europe

The biggest historical effect was not that Europe stopped being religious. It was that religion lost some of its monopoly over knowledge, morality, and politics.

When thinkers argued that moral life did not require one established church, that weakened confessional states. When they attacked miracles and revelation, they pushed religion into a more private sphere. When they criticized clerical privilege, they also weakened part of the Old Regime.

This helps explain why the textbook says the Enlightenment transformed religion from something highly public and political into something more private and reflective. That is a statement about **secularization**, not complete unbelief.

Students should also remember continuity. Some thinkers pursued a **Christian Enlightenment**, trying to reconcile Christianity with reason rather than reject faith. That is the strongest counterweight to any sweeping claim that the Enlightenment destroyed religion.

> **Key Term: Christian Enlightenment**
> An approach that tried to reconcile Christian belief with reason, science, and moderate reform.

This continuity matters in AP writing because it shows qualification. A top-scoring answer might argue:

- The Enlightenment weakened traditional church authority
- It spread deism and skepticism more than atheism
- Yet religion remained important, and some thinkers sought reform rather than rejection

That structure shows causation, distinction, and complexity all at once.

For comparison questions, students can also note regional differences:

- **England** was strongly linked to deism and debates over natural religion
- **France** was known for philosophes and anti-clerical criticism
- **Scotland** was important for skepticism, especially Hume

These differences can turn a basic answer into a stronger one because they show that the Enlightenment was not identical everywhere.

## Key Point Checklist

_This article has covered the following key knowledge points:_

- The Enlightenment in the **eighteenth century** applied reason and evidence to religion
- **Secularization** meant that intellectual and political life became less dominated by religious authority
- **Deism** accepted a rational creator God but rejected miracles, revelation, and church dogma
- **Voltaire** is best used as an example of deism, anti-clericalism, and religious toleration
- **Skepticism** questioned whether religious claims could be proved with certainty
- **David Hume** attacked miracle claims and revealed religion using standards of evidence
- **Pierre Bayle** argued that moral society did not require religious uniformity
- **Atheism** was a more radical and less common position than deism or skepticism
- **Baron d’Holbach** is the clearest Enlightenment example of atheism and materialism
- **Denis Diderot** helped spread secular and critical inquiry through the Encyclopédie
- Enlightenment criticism often targeted **organized religion and clerical privilege** more than religion itself
- A **Christian Enlightenment** also existed, showing that some thinkers tried to reconcile faith and reason

## Key Terms and Concepts

- secularization
- philosophes
- anti-clericalism
- deism
- religious toleration
- skepticism
- atheism
- materialism
- Christian Enlightenment


The Enlightenment - Deism skepticism and atheism spread