The World's Shortest
The web contains numerous resources on the subject of libertarianism, including some very extensive FAQ's that can be pretty daunting for someone who just wants to know the basics. I have therefore created this short FAQ to cover the topics that (in my experience) come up most often when I am talking about libertarianism to the uninitiated:
1. The simple definition. A libertarian is someone who, in general, supports government policies that favor individual liberty in all matters, whether economic, personal, or social.
Libertarians are frequently characterized as "conservative on economic issues and liberal on personal issues." That's not a bad definition, but it's kind of like saying vodka is "half screwdriver and half white Russian." It implies that libertarians are being inconsistent, whereas in fact libertarianism is more consistent than either conservatism or liberalism. I prefer to say, "Conservatives are frequently libertarian on economic issues, and liberals are frequently libertarian on personal issues." (I would also say that conservatives are usually authoritarian on personal issues, and liberals are usually authoritarian on economic issues.)
A list of policies that most libertarians support would include: legalization of drugs, legalization of all consensual sexual acts between consenting adults (including sodomy and prostitution), abolition of government censorship in all its forms (including restrictions on pornography), free trade, noninterventionist foreign policy, abolition of rent control, abolition of the minimum wage, abolition of farm and business subsidies, abolition of arts subsidies, privatization of Social Security, abolition of welfare, and drastic reduction of taxes.
For a decent indicator of whether you are a libertarian according to the simple definition, take the World's Shortest Political Quiz.
2. The more complex, philosophical definition. A libertarian is someone who, as a general rule, supports the non-aggression ethic (or as some people call it, the non-aggression axiom, or NGA). The non-aggression ethic holds, to quote David Boaz's Libertarianism: A Primer, that "No one has the right to initiate aggression against the person or property of anyone else."
Two phrases in this statement bear special emphasis. The first is "initiation of aggression." Libertarians strongly support the right of individuals to respond to aggression against them -- i.e., everyone has the right of self defense. What libertarians oppose is the initiation of force (or aggression) against others.
The second important phrase is "no one." Libertarians believe that no means no. People do not acquire the right to initiate aggression against others simply because they are agents of the state, or because they get the majority of people to agree with them. The key issue is not who uses aggression, but rather the purpose for which it is used. Libertarians believe, for the most part, that aggression is only justified if used to limit the initiation of aggression by others.
3. The crass political definition. A Libertarian (note the capital L) is a member of the Libertarian Party, a national political party in the United States. A libertarian and a Libertarian are not necessarily the same thing, but in general, the LP advocates policies that libertarians (small l) are likely to support.
The LP's official Statement of Principles says, "We hold that all individuals have the right to exercise sole dominion over their own lives, and have the right to live in whatever manner they choose, so long as they do not forcibly interfere with the equal right of others to live in whatever manner they choose." That's a pretty good statement of the motivating ideal behind libertarianism. Nonetheless, many libertarians decline to support the LP for various reasons, most often the perception that the LP is ineffective or dominated by especially dogmatic libertarians.
Minarchists believe that government should be reduced to the smallest size necessary to protect individual rights of person and property. Minarchists are willing to tolerate a low level of taxes and some other forms of government power (such as the power to subpoena witnesses), even though these practices are strictly speaking violations of individual liberty, because they are necessary to prevent even greater violations of individual liberty that would take place otherwise. Minarchists usually support a state-run military, police force, and justice system.
Anarchists (or anarcho-capitalists, a term used to distinguish them from anarchists of the socialist or bomb-throwing variety) oppose the existence of any government, even a small one. Anarcho-capitalists frequently argue that having a government at all necessarily violates the non-aggression ethic (see definition 2 above). They contend that it is a violation of individual liberty to take people's money or property from them, even if the money or property will be used to defend their remaining money and property. Anarcho-capitalists usually envision private enforcement agencies and courts that would compete for the voluntary business of individuals seeking protection against the violation of their rights by others.
In case you're wondering, I consider myself a minarchist.
In the 19th century, the term "liberal" generally meant someone who favored individual liberty and opposed the expansion of state power. In Europe and in much of the rest of the world, it still means that. But in America, the term "liberal" was adopted by people who favored extensive government intervention in the economy -- people who elsewhere in the world would have been called progressives, social democrats, or socialists. Meanwhile, "conservative" continued to refer to people who favored the use of state power for the preservation of certain religious and cultural practices. The original liberals were thus left without a label. People who still cleave to the ideal of individual liberty in all spheres of life, like the 19th century liberals, now usually call themselves either libertarians or classical liberals.
Heroes of Classical Liberal Thought
From the top, left to right: John Locke, David Hume, Adam Smith, Thomas Jefferson, John Stuart Mill, Henry David Thoreau, Friedrich A. Hayek.