How did Jean-Jacques Rousseau try to harmonize individual liberty with the authority of the state?

He laid out a plan for government in his Social Contract. He wanted natural liberty to be civic liberty

Explanation:

Jean-Jacques Rousseau stated that the government role within the country should be limited (minimum). He believed that ensuring the rights of the citizens is a part of that minimum role.

According to him, individual liberty cannot be achieved if it left to the whim of the citizens alone since human had egoistical tendencies to abandon other people's needs as long as we can fulfill our own needs. Because of this, government authority is needed in order to harmonize individual liberty.