… is from page 128 of Benjamin A. Rogge’s May 1964 Teachers College Record essay, “Complexity in Hades,” as this essay is reprinted in A Maverick’s Defense of Freedom , the 2010 collection of Ben Rogge’s essays that is edited by Dwight Lee (original emphasis):
I would add that because I believe a public school system must by right be subservient to the public, and because I believe the public to be often wrong and intolerant, I attach great significance to the private sector of education at all levels. If the bad guys of whatever persuasion gain the ascendancy, as so often happens in societies under stress, let there be islands of at least temporary resistance to the trends of the day.
DBx: Yes. (I would add to the above the observation that even societies not under stress typically get bad guys – and bad gals – in positions of political power.)
The case for the separation of school and state  turns not only, indeed not mainly, upon the strong likelihood that schools subject to market competition will produce better instruction  considered narrowly – that is, better teaching of subjects such as grammar, math, history, literature, and science. The strongest argument for the separation of school and state is that it is extraordinarily dangerous to have the state in the business deciding which ideas and values are, and which aren’t, to be taught and conveyed.