As reported by the huffingtonpost.com, "… 32 million adults in the U.S. can’t read." This in a country that not only has the best university system in the world, by far, but is also the richest nation in the world, by far, and somehow is able to pride itself on being egalitarian in its governance. The importance of literacy is to know well how to read and write, as well as being able to know well basic mathematical skills, which are absolutely mandatory unless such a person actually desires to be dependent upon others, because of these handicaps, forever. Additionally, literacy and learning, has historically been so important to civilizations and nations, that learning, and being literate, was something left, until the most modern times, exclusively in the domain of the ruling class, in conjunction with the priestly class, so as to quite obviously, keep the people as a whole, ignorant and exploitable.
This present age, is supposed to be an age in which all are educated, but quite obviously that is not the case; and the fact that it isn't the case, can only logically be attributed to the fact that those in power, desire to see that there is a permanent underclass always present in this country that can be utilized and controlled by the power brokers, so that, at their will, they can incarcerate such when there are no clear and present danger from enemies within or without, and to indoctrinate and to train such, so as to fight enemies whether within or without, when so necessary. The reason why that underclass is so important is because, all wars, domestic or not, no matter how sophisticated or powerful the weapons may be, necessitate on some level, boots on the ground, and those boots on the ground are the very ones that are most in danger of losing their lives or limbs, of which, the desire of the ruling class, is to have the underclass be the ones that are doing the dying, for it is always going to be a rich man's war, and a poor man's fight.
While it can be stated that knowledge does not necessarily require literacy, in point of fact, for all practical purposes, it does. So too, knowledge to come about for anybody at any level, is going to require self-effort by the person so being taught, which means, that the teacher, herself, needs to be competent in being able to actually teach as well as to keep their pupils, engaged. Additionally, no subject can ever be mastered, unless that given person makes a concerted effort to master it, which necessitates good source materials, good teachers, and the application of that knowledge so being obtain, being proved by the demonstration of passing tests, other skill based exams, and real world experience.
Those that are ignorant, are for the most part, enthralled to those that are not, because without knowledge, that person is not independent, but rather dependent upon others, and there are many people that do not truly have the best interests of the person that knows very little in mind. So too, those that are knowledgeable often don't feel a need to play fair or to be charitable, because the sad fact of the matter is great civilizations, again and again, are actually built, almost always, upon the backs of those that have been yoked, so that those that are in the ruling class, deliberately exploit the poor and ignorant, to support their riches and pleasures.
Thus, those without knowledge, are never free, and never will be.