Philosophy of education has always been one of the weakest subfields of both philosophy and education; it is both unpopular, with relatively little material published in it, and disconnected from philosophy (by being insufficiently rigorous for the tastes of many "real" philosophers) and from the broader study and practice of education (by being too philosophical, too theoretical).
Nonetheless, there are certain key voices in philosophy of education, who have contributed in large part to our basic understandings of what education is and can be, and who have also provided powerful critical perspectives revealing the problems in education as it has been practiced in various historical circumstances. There is one particular strand in educational philosophy that stands out as of extreme importance in the present time, which may be identified as the "Democratic Tradition", because it is a product of philosophers who, seeking to establish or preserve democracy, turn to education as a method of choice.
Plato is the earliest important educational thinker. Education is, of course, a relatively minor part of his overall philosophical vision, but it is an important one. He saw education as the key to creating and sustaining his Republic. He advocated extreme methods: removing children from their mothers' care and raising them as wards of the state, with great care being taken to differentiate children suitable to the various castes, the highest receiving the most education, so that they could act as guardians of the city and care for the less able. Education would be holistic, including facts, skills, physical discipline, and rigidly censored music and art. For Plato, the individual was best served by being subordinated to a just society. Thomas Jefferson, perhaps the first thinker to conceive of systematic public education in the modern sense, followed Plato in many respects, adapting him to the particular situation of American democracy in his own time.
Rousseau, though he paid his respects to Plato's philosophy, rejected it as impractical due to the decayed state of society. Rousseau also had a different theroy of human development--where Plato held that people are born with skills appropriate to different castes (though he did not regard these skills as being inherited), Rousseau held that there was one developmental process common to all humans. This was an intrinsic, natural process, of which the primary behavioral manifestation was curiosity. This differed from Locke's tabula rasa in that it was an active process deriving from the child's nature, which drove the child to learn and adapt to its surroundings.
As Rousseau wrote in his Emile, all children are perfectly designed organisms, ready to learn from their surroundings so as to grow into virtuous adults. But, due to the malign influence of corrupt society, they often failed to do so. Rousseau advocated an educational method which consisted of removing the child from society (i.e., to a country home) and alternately conditioning him through changes to environment and setting traps and puzzles for him to solve or overcome.
Rousseau was unusual in that he recognized and addressed the potential of a problem of legimation for teaching. He advocated that adults always be truthful with children, and in particular that they never hide the fact that the basis for their authority in teaching was purely one of physical coercion--"I'm bigger than you." Once children reached the age of reason (about 12), they would be engaged as free individuals in the ongoing process of their education.
B.F. Skinner's perhaps largest contribution to education philosophy in his text Walden Two wherein he details the failings of society and education, as one is intricately and intrinsically linked to the other. Skinner shares Rousseau's lack of faith of in society. His behaviorist theories play largely in his proposed ideas of social engineering. John Dewey. More pending.
Paulo Freire[?] contributes a philosophy of education that comes not only from the more classical approaches stemming from Plato, but also from modern Marxist and anti-colonialist thinkers. In fact, in many ways his Pedagogy of the Oppressed may best be read as an extension of or reply to Frantz Fanon's Wretched of the Earth, which laid strong emphasis on the need to provide native populations with an education which was simultaneously new and modern (rather than traditional) and anti-colonial (that is, that was not simply an extension of the culture of the colonizer).
Freire is best-known for his attack on what he called the banking concept of education[?], in which the student was viewed as an empty account to be filled by the teacher. Of course, this is not really a new move--Rousseau's conception of the child as an active learner was already a step away from the tabula rasa (which is basically the same as the "banking concept"), and thinkers like John Dewey and Alfred North Whitehead were strongly critical of the transmission of mere facts as the goal of education.
More challenging, however, is Freire's strong aversion to the teacher-student dichotomy. This dichotomy is admitted in Rousseau and constrained in Dewey, but Freire comes close to insisting that it should be completely abolished. Of course, this is strictly inconceivable in absolute terms (there must be some enactment of the teacher-student relationship in the parent-child relationship), but what Freire suggests is that a deep reciprocality be inserted into our notions of teacher and student. Freire wants us to think in terms of teacher-student and student-teacher, that is, a teacher who learns and a learner who teachers, as the basic roles of classroom participation.
This is one of the few attempts anywhere to implement something like democracy as an educational method and not merely a goal of democratic education. Even Dewey, for whom democracy was a touchstone, did not integrate democratic practices fully into his methods. (Though this is in part a function of his peculiar attitudes toward individuality.) However, in its early, strong form this kind of classroom has sometimes been criticized on the grounds that it can mask rather than overcome the teacher's authority.
Hannah Arendt largely avoided education as a subject, but she did so for reasons which are very interesting to educational philosophy. Her thoughts on the subject are recorded in one of the essays collected in Between Past and Future, entitled, "The Crisis in Education." In this essay, Arendt precedes to argue that any attempt to create democracy through educational methods was a form of tyranny...(Continuation pending)
E.D. Hirsch[?] would surely identify himself as someone interested in educating for democracy, but he is grouped separately here because his philosophy is basically a counter to Deweyan pragmatic education, and because, like Arendt, he is concerned with preparing children for an existing order, rather than working towards a new one, let alone instituting the practice of democracy as a part of education...(Continuation pending)