Thomas Jefferson - That government is best which governs the least,...
That government is best which governs the least, because its people discipline themselves.
This quote is actually from Henry David Thoreau's essay entitled "Civil Disobedience." The entire passage reads:
I heartily accept the motto,—“That government is best which governs least;” and I should like to see it acted up to more rapidly and systematically. Carried out, it finally amounts to this, which I also believe,—“That government is best which governs not at all;” and when men are prepared for it, that will be the kind of government which they will have. Government is at best but an expedient; but most governments are usually, and all governments are sometimes, inexpedient.
—Thoreau, Civil Disobedience