The Founding Fathers of the United States were heavily influenced by prior ideas about government, notably the Enlightenment, which challenged the preceding feudal system.

Feudalism, dominant in Europe from approximately 900s to 1500s, was a hierarchical system with the Monarch at the top, followed by nobility, knights, merchants, farmers, and peasants. This system was justified by the belief that it was God's will. Peasants and serfs were essentially property tied to the land.

The Enlightenment (roughly 1685-1815) was an intellectual movement that increasingly questioned the feudal structure. It proposed that the universe operates according to knowable laws that could be discovered through logic and the scientific method, leading to a better life. Many Enlightenment thinkers were deists, believing God set up the universe with laws and then let it run.

John Locke introduced the concept of natural rights: life, liberty, and property, which are inherent to all individuals regardless of their social standing. Locke emphasized religious freedom, having witnessed the devastating religious wars in Europe. However, his ideas on liberty had limitations, as he argued against atheism.

Locke recognized that despite natural rights, societies face the problem of power, where the strong can prey on the weak. To address this, he proposed the social contract: people give up some personal freedom to the state in exchange for the protection of their natural rights, enforcement of contracts, and defense against threats, both foreign and domestic.

The social contract is based on the 'consent of the governed.' Explicit consent involves a deliberate choice, such as becoming a naturalized citizen. Implicit consent is when individuals are citizens by birth and accept the governing rules simply by living within the society.

If an individual violates the social contract by infringing on others' rights, the response is punishment (e.g., imprisonment, fines). Conversely, if the government violates its part of the contract by failing to protect natural rights, Locke argued for the overthrow of that government, as exemplified by the beheading of Charles I, which Locke experienced.

These Enlightenment ideas, particularly those of John Locke, profoundly influenced the Founding Fathers. The Declaration of Independence directly reflects Locke's philosophy, including the phrase 'consent of the governed' and Jefferson's 'life, liberty, and the pursuit of happiness' as a nod to Locke's 'life, liberty, and property'.