Opinions on what constitute liberty can vary widely, but can be generally classified as positive liberty and negative liberty. Positive liberty asserts that freedom is the ability of society to achieve an end. However, in modern time, liberty is generally considered to be the concept of negative liberty. This refers to an individual's liberty from being subjected to the authority of others. In this negative sense, one is considered free to the extent to which no person interferes with his or her activity. The social contract theory, invented by Hobbes, John Locke and Rousseau, were among the first to provide a political classification of rights, in particular through the notion of sovereignty and of natural rights. The thinkers of the Enlightenment reasoned the assertion that law governed both heavenly and human affairs, and that law gave the king his power, rather than the king's power giving force to law.
In the United States, more than 200 towns and counties are called Liberty. In this past historic election year, a new documentary explores the messy business of America's most celebrated value in a number of ways and places.