The Transcendence of Marxist Criticism?

“Marxism is a materialist philosophy”, rather than an idealist philosophy, “…it tries to explain things without assuming the existence of a world or of forces beyond the natural world around us, and the society we live in” (Barry 156). By definition, it contrasts with Liberal Humanism which is much more of an idealist philosophy.
A commonly thought belief for liberal humanists is that human nature is unchanging, throughout all time and all places on this third rock from the sun. Personally, I find contradiction in this statement itself, but when seen from a Marxist point of view, this statement is completely and utterly false.
Humanity is a developing species and we relish change, even strive for it, each day. This is where the contradiction is: it is an unchanging attitude of humanity that humans enjoy change. It is true of all humans, from any time period, that change is necessary and welcomed.
The saying, ‘We do not welcome change,' is only that, a saying.
Literature is a perfect example of the changes in humanity throughout time. In the early days of history, that which is recorded, not many people could read or write—it is because of this that history of the written word is so incomplete—so for a long time, the ideal of literature was placed on a pedestal and only the wealthy and intelligent could become prominent at reading and even at writing their own letters.
And for so many centuries of human existence, only a certain social class was able to read and write literature, which meant that the literature being written was truly for the enjoyment or tutoring of a specific social class—the wealthy, white, male class.
Does this sound like Marxism yet?
Marxism could never have been discovered since those who were excluded from this upper class of literate humans were not able to learn the necessary components for reading and writing so they could not discern what measures the upper class were taking to exclude other from a liberal humanist perspective of literature that would decide the fate of literary work for the future world to build off of.
Greek philosophy has always been a strong source for knowledgeable information and even today, people read Aristotle and Plato, even Socrates' stories and these men lived four or five thousand years ago. One would think that knowledge and paths of study would have changed throughout all those years, but because the idea of liberal humanism was so ingrained, it took some time for people to break away from its ideology—but people wanted to all along and welcomed the change when it came.
This liberal humanist idea, stemming from ancient Greece and that society’s philosophers, started the general belief of transcendent literature. The Canons of great literature are a collection of works that are believed to be acceptable forms of teaching material for all eras of humanity. It is the idea of liberal humanists that these literary works are important and relate to every person, in any place and at any time.
I disagree with this idea although I do enjoy many of the canonized books. However, my enjoyments comes purely from the fact that I, as a writer and reader of literature, enjoy epic stories like Homer and written art in the form of plays like Shakespeare. Men like Dante I can live without, although, I do see the importance of having read these texts—mainly because one cannot discuss them intelligently without having read them. I do not believe that all people need to have read these canons to be intelligent and knowledgeable in the study of literature and certainly these specific works are not right for every person. Interests of one person do not go hand-in-hand with the interests of another and as a Marxist would say, it is only because of our social pressures, built up by this liberal humanist idea, that makes schools include these works and convinces students that they are important.
“Marxist Literary Criticism maintains that a writer’s social class, and its prevailing ‘ideology’ (outlook, values, tacit assumptions…) have a major bearing on what is written by a member of that class.” (Barry, 158).