Marx Quote:

“The materialistic doctrine, that men are the product of conditions and education, different men, therefore, the products of other conditions and changed education, forgets that circumstances may be altered by men and that the educator has himself to be educated. It necessarily happens, therefore, that society is divided into two parts, of which one is elevated above society. The occurrence simultaneously of a change in conditions and human activity can only be comprehended and rationally understood as a revolutionary fact.”  —Marx. (From Theses on Feuerbach)

(Socialist Standard, September 1922)