According to Montesqieu, what is the advantage of the seperation of powers

He felt that the best way to secure liberty and limit corruption in a government was to divide the powers into separate factions that would have the ability to check on one another. No faction would have complete power and all the other factions would have the power to vote down or change things thus never allowing one group to become too powerful. The US Constitution was based on Montesquieu's ideas