Here is the most fundamental, most important argument in favor of liberty that I’ve ever come across, taken from Chapter 2 of my glorious copy of Hayek’s The Constitution of Liberty: The Definitive Edition (bold text highlighted by me):
“Man learns by the disappointment of expectations. Needless to say, we ought not to increase the unpredictability of events by foolish human institutions. So far as possible, our aim should be to improve human institutions so as to increase the chances of correct foresight. Above all, however, we should provide the maximum of opportunity for unknown individuals to learn of facts that we ourselves are yet unaware of and to make use of this knowledge in their actions. It is through the mutually adjusted efforts of many people that more knowledge is utilized than any one individual possesses or than it is possible to synthesize intellectually; and it is through such utilization of dispersed knowledge that achievements are made possible greater than any single mind can foresee. It is because freedom means the renunciation of direct control of individual efforts that a free society can make use of so much more knowledge than the mind of the wisest ruler could comprehend.
From this foundation of the argument for liberty it follows that we shall not achieve its ends if we confine liberty to the particular instances where we know it will do good. Freedom granted only when it is known beforehand that its effects will be beneficial is not freedom. If we knew how freedom would be used, the case for it would largely disappear. We shall never get the benefits of freedom, never obtain those unforeseeable new developments for which it provides the opportunity, if it is not also granted where the uses made of it by some do not seem desirable. It is therefore no argument against individual freedom that it is frequently abused. Freedom necessarily means that many things will be done which we do not like. Our faith in freedom does not rest on the foreseeable results in particular circumstances but on the belief that it will, on balance, release more forces for the good than for the bad.
It also follows that the importance of our being free to do a particular thing has nothing to do with the question of whether we or the majority are ever likely to make use of that particular possibility. To grant no more freedom than all can exercise would be to misconceive its function completely. The freedom that will be used by only one man in a million may be more important to society and more beneficial to the majority than any freedom that we all use.
It might even be said that the less likely the opportunity to make use of freedom to do a particular thing, the more precious it will be for society as a whole. The less likely the opportunity, the more serious will it be to miss it when it arises, for the experience that it offers will be nearly unique. It is also probably true that the majority are not directly interested in most of the important things that any one person done by the individuals. But majority action is, of necessity, confined to the already tried and ascertained, to issues on which agreement has already been reached in that process of discussion that must be preceded by different experiences and actions on the part of different individuals.
The benefits I derive from freedom are thus largely the result of the uses of freedom by others, and mostly of those uses of freedom that I could never avail myself of. It is therefore not necessarily freedom that I can exercise myself that is most important for me. It is certainly more important that anything can be tried by somebody than that all can do the same things. It is not because we like to be able to do particular things, not because we regard any particular freedom as essential to our happiness, that we have a claim to freedom. The instinct that makes us revolt against any physical restraint, though a helpful ally, is not always a safe guide for justifying or delimiting freedom. What is important is not what freedom I personally would like to exercise but what freedom some person may need in order to do things beneficial to society. This freedom we can assure to the unknown person only by giving it to all.
The benefits of freedom are therefore not confined to the free—or, at least, a man does not benefit mainly from those aspects of freedom which he himself takes advantage of freedom of some therefore applies to the freedom of all. But it is still better for all that some should be free than none and also that many enjoy full freedom than that all have a restricted freedom. The significant point is that the importance of freedom to do a particular thing has nothing to do with the number of people who want to do it: it might almost be in inverse proportion. One consequence of this is that a society may be hamstrung by controls, although the great majority may not be aware that their freedom has been significantly curtailed. If we proceeded on the assumption that only the exercises of freedom that the majority will practice are important, we would be certain to create a stagnant society with all the characteristics of unfreedom.”
That the true benefit of a free society stems from the uses of liberty by other, unknown people, is the most fundamental argument in favor of liberty for all. Internalizing this small block of text from Hayek is worth far more to understanding the importance of a free society than years’ worth of slogging through treatises and dissertations.