which philosopher developed the concept of the social contract
Thomas Hobbes was an English philosopher who influenced nearly all-western political philosophy. He is best known for his contribution to the social contract theory of origin of state. Hobbes was greatly influenced in his ideas by the English civil war that broke out in 1642.
The largest difference between Rousseau's social contract and Hobbes' is the state of nature. For, as previously stated, Hobbes' state of nature between men was that of war and diffidence. Additionally, Hobbes believes that social order is a state of nature.