Baron de Montesquieu
In his book, Montesquieu advocated a Separation of Powers in government — Executive, Legislative and Judicial. He believed it was essential to have the three parts of government controlled by different powers. Additionally, he further suggested that a government must have a system of checks and balances between the branches of government. In this system, each branch had a check against the powers of the other two branches, creating a balance of governmental power.