Years ago, when I had just begun work on my Masters degree, I sat in a class listening to a PhD candidate descant on one of his favourite topics: Homoeroticism in the Renaissance. It was a hot topic at the time, and he was extremely well read and very, very good in expounding upon the subject. I had the misfortune to be stuck repeatedly in giving my presentations after him in class, and I was painfully aware of how much better informed, how much a better writer, just how much better he was in general than I. Everything he wrote was publishable, and he was encouraged to publish as much as possible. No one would rate my work so highly.
On that day he was giving a presentation on Spenser, and I was once again to follow him. He went through the poem, explaining how each part fit into his theory, except for one brief stanza, where he struggled and made his point in a very clumsy fashion. I was intrigued, because the evidence he needed was right in front of him, in a reference Spenser made to one of Ovid's myths, and he just missed it. So I asked him at the end of his presentation why he made the point the way he did when he could have made use of Spenser's reference to Ovid and made his point much more elegantly. His response was an indifferent shrug. "I wouldn't know," he said. "I never read Ovid."
I could never look at him the same way again. He knew everything about modern theorists and their theories, but he was totally uninformed about the Roman and Greek literature and he did not care. He thought he was not missing anything. He could not have been more wrong. The writers of the past read the writers who came before them, and filled their works with references to the earlier works. Shakespeare and his contemporaries filled their works with references to Vergil, Ovid, Plutarch, Livy, Cicero, Seneca, Homer, the Bible. Writers commonly did this up until our own century. Without a basic knowledge of the early writers, the modern readers is missing a huge chunk of the meaning and power of these writers.
My own education in the classics was accidental. In my undergraduate years I had repeatedly been among the last to sign up for courses, which meant the courses had wanted to take were all full and I was stuck taking what was left. I never got to take the hot subjects, and I was left with the stuff no one else wanted, which included repeated courses in the classics. I was disgruntled at the time, and became both elated and disgruntled as my education wore on. Being grounded in the classics at that time was like having eyes when all others were blind. Unlike this genius and others of his ilk, I could see the references and the subtexts. A knowledge of the classics also helped me to see through much of the modern 'theories' and to understand them for the nonsense they were.
I also could see the lie of the 'newness' of modern literary movements. Take one of the popular forms of writing from the 80's: meta-theatre and meta-fiction. In both cases, both the fiction and the theatre draw attention to their status as fiction or theatre. Say, for example, a play about putting on a play, or a movie in which a character explains that they are doing what they do because that's how it they were written. That sort of thing. New and cutting edge, right? Wrong. It was done before and better. Take The Knight of the Burning Pestle, for instance, written by Beaumont and Fletcher, the two men who took over writing for the King's men after Shakespeare retired. In this play two characters in the audience insist on changing the scenes to suit their fancy. Or Laurence Sterne's Tristram Shandy, a work which one wag described as "A post modern classic written three hundred years before there was any modernism to be post over."
The downside was that I appeared to be the only one who knew these things. To my peers, I was the blind one.
These books give the reader something the modern theorists cannot and never shall: perspective. To the modern theorist the only value which they seem to admire is the value of the 'new', and that is not a value that endures. By sending your mind across the centuries a reader can gain a far greater perspective and see beyond the value of that which is new, and perhaps begin to grasp the values that are eternal.