A common misconception that the focus of a libertarian is 'a conservative with socially liberal stances'. While the social concerns are debatable in the libertarian community, there is one fundamental philosophy that libertarians abide by: Maximized freedom. The libertarian philosophy is that, for the most part, people are capable of governing themselves. That no "authority" should attempt to inflict a particular mindset, nor should they attempt to define and dictate the individual. Libertarians advocate individualism, and oppose collectivism. Because to a libertarian, the greatest blessing is a free mind.
So is it a sound philosophy? To an individual who can realistically address economic concerns, and to an individual who identifies with free, individualized thought, libertarianism is quite stable.
Libertarianism is a sound political philosophy. It strives for freedom both economically and socially, and it has actually gained many followers. The Triple Nine Society, which is more exclusive than Mensa, is composed mainly of libertarians and anarchists. While many from the left are drawn towards libertarianism because of their beliefs on social issues such as recreational drugs and gay marriage, many are also drawn from the right for their views on economic freedom and growth. Libertarianism is perhaps the toughest viewpoint to argue against.
If one needs an example for this, search Being Classically Liberal on Facebook, read through some of their studies and content, and then challenge the admins or the followers to debates on economics and social issues.
Yes, Libertarianism is a sound political philosophy. While I don't necessarily agree with all the libertarian ideas, it is a sound political philosophy. And really, even if it isn't, it doesn't really matter. it challenges the two main political parties, keeps them honest, makes them think about what they are saying and doing and right now, the Republican party, rightfully, is moving more towards the libertarian ideal, mostly because of the Tea Parties, which practice very libertarian ideas of their own.
No, libertarianism is not a sound political philosophy as it assumes too much about the nature of agency and will. Libertarianism assumes that when given agency, an individual will most often act in good will, however, this is not always the case. There are many who would abuse such a political system.
Go on facebook and search for all the Libertarian pages that are available. Almost all of them are filled with confused conservatives. They talk about the same things the Republican pages do. They want liberty and free markets and they hate Obama and they post stupid pictures of snakes that say don't tread on me.
Look at a picture of a group of Libertarians meeting up and you will notice that it is a giant crowd of younger conservatively dressed white people. The only difference I see is that Libertarians want drugs to be legalized, everything else is garbage sloganeering.
Clinton freed up some regulations in the 90's and big businesses exploited it until they were caught and the economy collapsed. This idea of free markets and other sloganeering based around freedom makes people feel all heroic and noble inside, but it is not realistic and has no logical basis in reality as a system that could work.