How can we benefit from the promise of government while avoiding the threat to freedom? Two broad principles embodied in our Constitution give an answer that has preserved our freedom so far, though they have been violated repeatedly in practice while proclaimed as precept.
First, the scope of government must be limited. Its major function must be to protect our freedom both from the enemies outside our gates and from our fellow-citizens: to preserve law and order, to enforce private contracts, to foster competitive markets. Beyond this major function, government may enable us at times to accomplish jointly what we would find it more difficult or expensive to accomplish severally. However, any such use of government is fraught with danger. We should not and cannot avoid using government in this way. But there should be a clear and large balance of advantages before we do. By relying primarily on voluntary co-operation and private enterprise, in both economic and other activities, we can insure that the private sector is a check on the powers of the governmental sector and an effective protection of freedom of speech, of religion, and of thought.
The second broad principle is that government power must be dispersed. If government is to exercise power, better in the county than in the state, better in the state than in Washington. If I do not like what my local community does, be it in sewage disposal, or zoning, or schools, I can move to another local community, and though few may take this step, the mere possibility acts as a check. If I do not like what my state does, I can move to another. If I do not like what Washington imposes, I have few alternatives in this world of jealous nations.
From the introduction to Capitalism and Freedom by Milton Friedman