The Enlightenment was greatly influenced by various philosophical ideas that challenged traditional beliefs and paved the way for a new era of rationality and progress.

John Locke was a key figure whose ideas laid the groundwork for the Enlightenment. In his work Two Treatises of Government, Locke emphasized the concept of natural rights – the idea that every individual has inherent rights to life, liberty, and property.

Another influential philosopher was René Descartes, who is known for his statement 'Cogito, ergo sum' (I think, therefore I am). Descartes emphasized the importance of reason and individual autonomy in understanding the world.

Montesquieu further contributed to the philosophical foundations of the Enlightenment with his book The Spirit of the Laws. Montesquieu advocated for the separation of powers within a government, which served as a check against tyranny and promoted the balance of authority.

These philosophical ideas formed the basis for many key Enlightenment concepts and principles, including the notion of a social contract, which suggests that individuals have an implicit agreement with the government in exchange for protection of their natural rights. The thinkers of the Enlightenment believed that this social contract was necessary to maintain order and protect individual freedoms.

The concepts put forth by Locke, Descartes, and Montesquieu were instrumental in shaping the intellectual foundation of the Enlightenment, influencing subsequent generations of thinkers and revolutionaries.