The natural rights philosophy has its roots in the ancient Greek and Roman philosophy. Aristotle argued that all humans have a rational nature and that certain fundamental rights and freedoms are essential for the realization of this nature. The Stoic philosophers developed the idea of *jus gentium* or "law of nations" which asserts that certain principles of justice are common to all humankind and that these principles provide a foundation for international law.
In the medieval period, the natural rights philosophy was further developed by Christian theologians such as Thomas Aquinas. Aquinas argued that natural law is based on the rational nature of human beings and that it is knowable through reason. He also argued that the natural law provides a basis for the legitimacy of political authority and that rulers who violate the natural law can be justly overthrown.
The natural rights philosophy had a profound influence on the development of political and legal thought in the West. It was a key inspiration for the English Bill of Rights (1689), the French Declaration of the Rights of Man and of the Citizen (1789), and the United States Declaration of Independence (1776). The natural rights philosophy continues to play an important role in contemporary debates about human rights, justice, and the legitimacy of political power.