• John Locke – Advocated natural rights (life, liberty, property) and the social contract, arguing that government authority derives from the consent of the governed.
• Voltaire – Championed freedom of speech, religious tolerance, and a critical stance against institutional dogma.
• Jean-Jacques Rousseau – Introduced ideas on the social contract and popular sovereignty, emphasizing that legitimate political authority lies with the people.
• Montesquieu – Developed the concept of the separation of powers, influencing the design of modern democratic institutions.
• Immanuel Kant – Elevated the role of human reason, arguing for autonomy in moral decision-making and exploring the limits of knowledge in his critical philosophy.