Final answer:
Jean-Jacques Rousseau was a philosopher and writer who, along with John Locke, significantly influenced Enlightenment political thought, notably through the development of social contract theory.
Step-by-step explanation:
Along with John Locke, René Descartes, and Voltaire, Jean-Jacques Rousseau was a significant figure during the Enlightenment era. Among the options provided, all four individuals could be described as philosophers and writers, as they contributed extensively to philosophical thought and literature of their time.
Rousseau was particularly known for his works on social contract theory, where he proposed ideas regarding the natural state of man and the importance of a collective agreement, or social contract, as the basis for civil society and governance.
Similarly, Locke's influential notions included the concept of natural rights to "Life, Liberty, and Property," which were revolutionary in setting the stage for subsequent political documents like the United States Declaration of Independence and the French Declaration of the Rights of Man and of the Citizen. Thus, Rousseau, along with Locke, played a pivotal role in shaping sociopolitical ideologies during the 18th century.