"Constitutional government and representative institutions are indispensable conditions to political liberty." 

-Mortimer Adler, 
summarizing the political philosophy of J.S. Mill

This quote sums up the modern, Western view of freedom. Because there are different types of people in the world - some strong and some weak, some violent and some docile - real liberty can only last where there is constitutional government.

Constitutional government establishes law which must be followed by the government as well as by the people, and puts all under government by laws rather than the whims of men.

And since nobody is truly free unless they consent to the laws which govern them, representative institutions are essential for the conditions of freedom.

Government is necessary for lasting freedom. 

History has shown that government is also the greatest potential enemy of freedom, so wise and effective constitutions and institutions need limits, separations of powers, checks and balances. Above all, freedom can only last if the people are vigilant in keeping government and institutions within the bounds of good constitutions.