Sheldon Richman explains, with lots of big words and references to Plato and whatnot, why the practical case for freedom and the moral case for freedom are inextricably intertwined (See? I can use big words too. So there.):
Success is nice, but the ethical test has priority. Some libertarians often say they would favor freedom even if it did not promote good things like prosperity because people have a right to freedom that is unrelated to its consequences. (Of course, they don’t believe that freedom could have bad consequences. But is that just a happy coincidence?…)
The concern of ethics, according to Aristotle, is to learn how such a being must think and act in order to flourish individually and as a member of society; the objective is “the practical life of man as possessing reason.” That’s why prudence (or practical wisdom) finds a place on his list of virtues. In Rational Man: A Modern Interpretation of Aristotelian Ethics, Henry B. Veatch elaborates on why ethics may be regarded as the art of living, although, to be sure, it is an art unlike all other arts.
So I, for one, don’t accept the division of the case for freedom into “the moral” and “the practical.” It’s a mistake, not to mention harmful to the cause.