The problem isn't about Principles, but instead about Rights and formulaic solutions to human society. It comes about when your definition and usage of Rights is a metaphysical one.
Thomas Sowell writes about this in A Conflict of Visions where he points out that those who hold the Constrained view of humanity, which generally includes traditional conservatives, think of Rights as use-defined or based on if they are actually present in the culture.
When Rights are metaphysical, many others can be added by metaphysical arguements and they can be balanced between each other by utilitarian principles of the "greater good" and the like.
He explains that this is why for the Unconstrained view holders (like the left) Rights held by the "many", like free speech", end up trumping a property right held by a lone individual.
"Rights" also suffer when held like an Ideology; as a magic formula that mere adherance to will solve all problems.
Sowell points out that Libertarians are a conflicted class and fall partly in with both views and have a problem therefrom. Keep in mind, however, that he uses the term Libertarian to describe himself.
When Rights are metaphysical, many others can be added by metaphysical arguements and they can be balanced between each other by utilitarian principles of the "greater good" and the like. He explains that this is why for the Unconstrained view holders (like the left) Rights held by the "many", like free speech", end up trumping a property right held by a lone individual.
"Rights" also suffer when held like an Ideology; as a magic formula that mere adherance to will solve all problems.
Sowell points out that Libertarians are a conflicted class and fall partly in with both views and have a problem therefrom.