Who wrote the famous political philosophy book "The Social Contract"?

Introduction / Context:
"The Social Contract" is one of the most important works in political philosophy, frequently cited in discussions about democracy, sovereignty, and the relationship between citizens and the state. General knowledge and political science exams routinely ask who wrote it. The question checks whether learners can correctly identify Jean Jacques Rousseau as the author among several other famous philosophers of the same era.

Given Data / Assumptions:

• The book title given is "The Social Contract".
• The options list major European thinkers associated with political ideas.
• The question refers to the original eighteenth century treatise.
• Only one of the philosophers listed is historically correct as the author.

Concept / Approach:
The key concept is the recognition of classic political philosophy texts and their authors. Jean Jacques Rousseau wrote "The Social Contract", which develops the idea that legitimate political authority arises from an agreement between free individuals. While Kant, Locke, Voltaire, and Montesquieu all wrote significant works on politics and reason, their major titles are different. The approach is therefore to recall which thinker is directly linked with this specific title and to avoid confusing related but separate works.

Step-by-Step Solution:
Step 1: Remember that "The Social Contract" argues that legitimate government is based on a contract or agreement among citizens. Step 2: Recall that this idea and this book are most closely associated with Jean Jacques Rousseau. Step 3: Consider Immanuel Kant. His major texts include "Critique of Pure Reason" and "Critique of Practical Reason". Step 4: Consider John Locke. He wrote "Two Treatises of Government" which also discusses contract ideas, but his book title is not "The Social Contract". Step 5: Consider Voltaire, a writer and philosopher known more for essays and letters criticising intolerance and fanaticism. Step 6: Consider Montesquieu, whose main work is "The Spirit of the Laws", not this title. Step 7: Since only Rousseau wrote a book actually titled "The Social Contract", he is the correct author.

Verification / Alternative Check:
Any reliable history of political thought or introductory political science text will list "The Social Contract – Jean Jacques Rousseau". School and college level notes often summarise the main ideas of this book under Rousseau's name. None of the other philosophers are associated with a primary work bearing this exact title. This repeated confirmation in multiple sources verifies that Rousseau must be chosen as the correct answer.

Why Other Options Are Wrong:
Immanuel Kant is central to moral and epistemological philosophy, but his main works do not include "The Social Contract". John Locke helped shape social contract theory but expressed it in "Two Treatises of Government" and other writings, not in a book with this title. Voltaire was a famous critic of religious intolerance and absolutism, yet he did not author "The Social Contract". Montesquieu wrote about separation of powers in "The Spirit of the Laws" and is not the author of this work.

Common Pitfalls:
Because Locke is also linked with social contract ideas, some students mistakenly select him just by associating theory rather than remembering the exact title. Another pitfall is to confuse "The Social Contract" with "The Spirit of the Laws" or other famous eighteenth century works. To avoid such errors, it is helpful to memorise a one line mapping for each, such as "The Social Contract – Rousseau", "Two Treatises of Government – Locke", and "The Spirit of the Laws – Montesquieu".

Final Answer:
The book "The Social Contract" was written by Jean Jacques Rousseau.