“In the mater of education as in all other matters the Communist Party is not merely faced by constructive tasks. In the educational system bequeathed to it by capitalist society, it must hasten to destroy everything which has made of the school an instrument of capitalist rule.”

As quoted in The Communist Manifesto (21 February 1848), p19-20.

Progress, Coexistence and Intellectual Freedom (1968), Dangers, The Threat to Intellectual Freedom
Context: A system of education under government control, separation of school and church, universal free education — all these are great achievements of social progress. But everything has a reverse side. In this case it is excessive standardization, extending to the teaching process itself, to the curriculum, especially in literature, history, civics, geography, and to the system of examinations.
One cannot but see a danger in excessive reference to authority and in the limitation of discussion and intellectual boldness at an age when personal convictions are beginning to be formed. In the old China, the systems of examinations for official positions led to mental stagnation and to the canonizing of the reactionary aspects of Confucianism. It is highly undesirable to have anything like that in a modern society.

Outlook for Socialism in the United States (1900)

Working Class Politics (1910)

Einstein did write this quote in "On Education" from 1936, which appeared in Out of My Later Years, but it was not his own original quip, he attributed it to an unnamed "wit".
Very popular in French: "La culture est ce qui reste lorsque l’on a tout oublié" (Culture is that which remains, if one has forgotten everything). Attributed in French to Édouard Herriot (1872-1957) and, in English, sometimes to Ortega y Gasset. Another French variant is "la culture est ce qui reste lorsqu'on a oublié toutes les choses apprises" (Culture is that which remains if one has forgotten everything one has learned), which appears in the 1912 book Propos Critiques by Georges Duhamel, p. 14 http://books.google.com/books?id=Xpk_AAAAIAAJ&q=%22la+culture+est+ce+qui+reste+lorsqu%27on+a+oubli%C3%A9+toutes+les+choses+apprises%22#search_anchor. And another English variant is "Culture is that which remains with a man when he has forgotten all he has learned" which appears in The Living Age: Volume 335 from 1929, p. 159 http://books.google.com/books?id=tHFRAAAAYAAJ&q=%22Culture+is+that+which+remains+with+a+man+when+he+has+forgotten+all+he+has+learned%22#search_anchor, where it is attributed to "Edouard Herriot, French Minister of Education". Another English variant is "Education is that which remains behind when all we have learned at school is forgotten", which appears in The Education Outlook, vol. 60 p. 532 http://books.google.com/books?id=dNcgAQAAMAAJ&pg=RA1-PA532#v=onepage&q=%22education%20is%20that%20which%20remains%22&f=false (from an issue dated 2 December 1907), where it is attributed to Ralph Waldo Emerson.
The saying is found in an 1891 article by Swedish writer Ellen Key https://en.wikipedia.org/wiki/Ellen_Key, "Själamorden i skolorna", which was published in the journal "Verdandi", no. 2, pages 86-98 (the saying is on p. 97). The same article was republished later as a chapter in her 1900 book "Barnets Århundrade". Here is the quote in Swedish ( p. 160 https://archive.org/stream/barnetsrhundrade02ellenkey#page/n167/mode/2up): Men bildning är lyckligtvis icke blott kunskap om fakta, utan enligt en ypperlig paradox: »det, som är kvar, sedan vi glömt allt, vad vi lärt». Here it is from the 1909 English translation of the book ( p. 231 https://archive.org/stream/centurychild00frangoog#page/n246/mode/2up): "But education happily is not simply the knowledge of facts, it is, as an admirable paradox has put it, what is left over after we have forgotten all we have learnt." From the way Ellen Key puts it, she doesn’t take credit for the saying, but rather refers to it as an already known “paradox” that she explicitly puts between quotation marks.
Misattributed

The Abolition of Work (1985)
Context: I am not playing definitional games with anybody. When I say I want to abolish work, I mean just what I say, but I want to say what I mean by defining my terms in non-idiosyncratic ways. My minimun definition of work is forced labor, that is, compulsory production. Both elements are essential. Work is production enforced by economic or political means, by the carrot or the stick. (The carrot is just the stick by other means.) But not all creation is work. Work is never done for its own sake, it's done on account of some product or output that the worker (or, more often, somebody else) gets out of it. This is what work necessarily is. To define it is to despise it. But work is usually even worse than its definition decrees. The dynamic of domination intrinsic to work tends over time toward elaboration. In advanced work-riddled societies, including all industrial societies whether capitalist or "communist," work invariably acquires other attributes which accentuate its obnoxiousness.
Usually—and this is even more true in "communist" than capitalist countries, where the state is almost the only employer and everyone is an employee — work is employment, i. e., wage-labor, which means selling yourself on the installment plan. Thus 95% of Americans who work, work for somebody (or something) else. In the USSR or Cuba or Yugoslavia or Nicaragua or any other alternative model which might be adduced, the corresponding figure approaches 100%. Only the embattled Third World peasant bastions — Mexico, India, Brazil, Turkey — temporarily shelter significant concentrations of agriculturists who perpetuate the traditional arrangement of most laborers in the last several millennia, the payment of taxes (ransom) to the state or rent to parasitic landlords in return for being otherwise left alone. Even this raw deal is beginning to look good. All industrial (and office) workers are employees and under the sort of surveillance which ensures servility.

"… la transformación del sistema educativo que ya está en marcha. Se eliminarán totalmente las escuelas prima— precarias."
Actos fallidos de Políticos en YouTube http://www.youtube.com/watch?v=SkuoHwqcldA.

Barry Hines 1970 interview

Source: Another World Is Possible : Globalization and Anti-capitalism (2002), Chapter 3, The Invisible Hand Is A Closed Fist, p. 86