the aim of a liberal education is to unsettle presumptions, to defamiliarize the familiar, to reveal what is going on beneath and behind appearances, to disorient young people and to help them to find ways to re-orient themselves
Which is either mere academic gibberish to hide the fact that they are saying nothing or a sign that the people saying it have some severe mental problems. In actual fact, nobody who is truly passionate about liberal arts as liberal arts, rather than as propagandizing instruments or spaces to say and do any stupid thing one pleases, puts much emphasis on "disorientation" and "re-orientation". And that is because when you pierce through all this jargonistic fog, what people really love about liberal arts, and the reason why liberal arts are absolutely ineliminable from education, is closer to what the term 'liberal art' originally meant.
The word indicates a kind of craft; it's a productive skill, and one who learns a liberal art becomes an artisan, shaping, and making, and adapting things to good and useful and beautiful ends. Liberal arts are distinguished in one way from servile arts, which are devoted to making oneself useful to other people, and in another way from the manual arts, which make material products (handiworks, things that can be manufactured, things made and shaped by hand). Thus liberal arts are the crafts that involve making those intellectual and imaginative constructions that assist each person in thinking and determining his or her own ends as a free individual. The liberal arts in this sense are literally the arts of free reason.
And it cannot be emphasized enough: they make things, and these things, along with the products of all the other arts, are what make up the material of civilization.
The traditional list of the liberal arts, of course, mention seven pure liberal arts, divided into three (the trivium) and four (the quadrivium). The trivium consists of arts that are concerned in some way with verbal constructions:
grammar
rhetoric
logic
These are ordered in the list from the less abstract (and thus more directly concerned with words as such) to the more abstract (and thus more concerned with adapting words to the use of intellectual life as such). What things do these arts allow you to make? Putting it very roughly, meaningful and useful sentences (enunciations), well-constructed compositions (discourses), and well-structured arguments (syllogisms).
The quadrivium consists of arts that are in some way concerned with mathematical constructions:
arithmetic
geometry
music
astronomy
The first two in the list have the more abstract constructions; what they produce are mathematical constructions precisely as such. What they produce are, respectively, enumerations and measurements. The second two are less abstract: what they produce are mathematical constructions as applicable to certain kinds of domain. Both of these terms were broader than they are today. The medievals held that everything, not just sound, had a sort of music to it: there was a sort of music to the spheres and a sort of music to the human body, and so forth. When they said these things they meant that there was an implicit mathematics to these things, one involving proportions and ratios. This is what the liberal art of music concerned itself with: patterns involving proportions and ratios (harmonies and disharmonies, consonances and dissonances, non-verbal analogies). (Music in our sense involves manual art as well as liberal art.) Astronomy, too, was not confined to the heavens; surveying and navigation used astronomy all the time to make calculations based on stable phenomena. And that's what the liberal art of astronomy concerned itself: calculations involving measurements of phenomena. You can see immediately that music in this sense is a particular sort of applied arithmetic, while astronomy in this sense is a particular sort of applied geometry.
If one does not wish to stretch the terms so far as to keep the liberal arts to seven, one does not need to do so. But the fact of the matter is that the liberal arts in this sense are all the crafts that make rational artifacts for rational life. A liberal art in this sense needs no defending; anyone who rejects liberal art in this sense is effectively rejecting education itself. A liberal art in this sense is obviously useful: its whole raison d'etre is to make things useful for the mind. And there's nothing so fuzzy or vague or useless as "disorientation and re-orientation" here.
These liberal arts play a crucial role in serious philosophical thought. From logic, arithmetic, and geometry we learn rational method. And all of the liberal arts fashion the tools and instruments all good philosophers use to think: literary constructions and compositions, rhetorical discourses and tropes, deductive and inductive arguments, tallies and equations, comparative measurements, patterns and proportions, and computations involving phenomena. These are the products of liberal craftsmanship; these are the works of the liberal artisan. Because the mind uses these things to make itself more fit for discovering and understanding the truth, whoever can make these things well can in principle think more clearly, reason more fully, and understand more deeply than one who cannot. (In practice it is a little more complicated than this, because one needs not only the skill to make these things well but also the good sense -- the prudence -- to apply them properly.)
To make good philosophers, then, you need to teach them liberal arts first, because it is the liberal arts that give them the intellectual tools to reason and understand on a far greater scale than they can manage on their own. Good philosophy begins in the workshop of thought, where one manufactures what one needs to reason well and understand fully. People who have no such workshop-skills will be limited by the tools they have available.
Needless to say, it follows from this that we currently educate people very poorly; it's not that people don't get these skills, but they must either be drawing on natural talents or actively seeking them out on their own. What they do get of them is largely slapdash and piecemeal (and this is true even of logic, which is where our current philosophical curricula fall down least). I know mine was. Ideally, philosophy students should be explicitly and actively encouraged to learn languages, study literature, work on their writing and speaking skills, do archival research with historians, do ethnographic studies with anthropologists, do field work and laboratory work (even if only minor things) with natural scientists, study mathematics as far as they can. In practice, we could probably do a great deal to improve philosophical education simply by adding to the requirements interdisciplinary courses in undergraduate and an interdisciplinary year in graduate, so that they can do more to hone the intellectual tools they have available.
But in the larger view, what's really needed is closer focus on liberal arts in the educational system generally. After all, not all good philosophical minds go into academic philosophy; you can find true philosophers in other professions and trades. Further, since the liberal arts produce works essential for a thriving civilization, we are all better off if everyone picks up as many such skills as they can. And, perhaps most importantly of all, since they are the arts above all else that assist us in living lives that are genuinely free and rational, we have a moral responsibility to insist that they be taught. It is the liberal arts that make us more than slaves.