When human beings live in small groups, conflicts can be resolved relatively easily as everyone knows each other. But society gets increasingly complex, we have to interact with strangers, yet we cannot trust them. Since then, laws have been made to deal with conflicts and disputes in society. The state was born also to ensure everyone in the society enforced the law. Along with that, each of us must give up some liberty in order to have a safer and more comfortable society. Most of the tradeoffs are reasonable. For example, to make traffic safer for the whole society, you have to give up the freedom to cross the red lights at your will, or to drink and drive. However, this tradeoff also pose a risk: those who are responsible for defending/ protecting and building the law – the government, the parliament and the courts – may abuse the power to their advantage. The Constitution is designed to prevent abuse of power, at least in theory. For example, the Constitution of many countries, including Vietnam, regulates the equality rights before the law men or women, rich or poor, power or not, are equal in the eyes of laws. Or in many countries around the world, the Constitution requires that the state must have separation of power. It is the concept whereby power must be divided, so that power is not focused on an organization that is vulnerable to abuse. The Constitution can be interpreted as a Rule of Laws. If a law, which goes against the Constitution, is not valid. You can also understand the constitution as a contract, the people give some rights to the State, in return, the State provides a number of services and mechanisms to ensure the interests of the people. Like court, defense, police force, infrastructure, etc. the right to freedom of the pursuit of happiness, freedom of speech, demonstration, etc. The two parties must strictly abide by the contract which has supreme value in this society.