According to Rousseau, man was first living in isolation and was satisfied/happy with little means. With time noble man discovered the utility and usefulness of labor and created a degree of provisional order. Men build shelters for themselves and families, stayed together under patriarchal stage. It brought first fall for man, wrenching him from the happiness to the 'patriarchal stage' and passed from a subsistence economy to an economy of productive development. 

 The emergence of metallergy and agriculture was indeed a great revolution, But iron and corn, which civilised men, ruined humanity. The cultivation of earth led to the enclosure of land, and this necessarily gave rise to the idea of property. Once men began to claim possessions, the inequality of men's talents and skills led to an inequality of fortunes. Wealth enabled some men to enslave other's; the very idea of possession excited men's passions, and provoked competition and conflict. Conflict led in turn to a demand for a system of law for sake of order and tranquility. The rich especially voiced this demand, for while the state of violence threatened everyone's life it was worse for the rich because it threatened their possessions also.  The result, says Rousseau, was the origin of civil society and laws, which gave new fetters to the poor, and new powers to the rich; which destroyed natural liberty for ever.

 It may however be noted here that Rousseau was not depicting the transition from state of nature to 'civil society' as a historical fact. Rather the above account has to be understood as hypothetical reasoning calculated to explain the nature of things, than to ascertain their actual origin.