“The quality of education given to the lower class must be of the poorest sort, so that the moat of ignorance isolating the inferior class from the superior class is and remains incomprehensible to the inferior class. With such an initial handicap, even bright lower class individuals have little if any hope of extricating themselves from their assigned lot in life. This form of slavery is essential to maintaining some measure of social order, peace, and tranquility for the ruling upper class.”