During the eighteenth century the French political philosopher Montesquieu proposed an analysis of governmental poker which came to be one of the most influential ideas in Western thought. In every political society, he said, there are three kinds of power; legislative power, executive power and judicial power. This theoretical analysis was accompanied by a corollary of profound practical importance. It was that the liberty of the citizens in any community varies with the degree to which those three governmental powers are held in separate hands. A free society is one in which legislative, executive and judicial powers are, or tend to be, kept separate. At the other extreme, concentration of legislative, executive and judicial powers in one person, or one group of people, is the essence of tyranny.