What was the effect of Montesquieu?

Charles-Louis de Secondat, Baron de La Brède et de Montesquieu was known as Montesquieu. He designed a new social class hierarchy that included the monarchy, aristocracy and the commons, completely eliminating the First, Second and Third estates. He reasoned the powers of the nobles to monitor the King had been greatly eroded, this theory was also championed by Robespierre during the French Revolution.