Elia confesses that he is not well-read. He has devoted himself to old English plays and various treatises, but is ignorant about anything in the way of science. He's so ignorant of geography that he doesn't know where Africa touches Asia, and knows so little about astronomy that he couldn't begin to pick out constellations. His friend M. failed to teach him of the laws of Euclid, and Elia knows nothing of modern languages, instead having picked up a little bit of Latin and even less Ancient Greek.
The thing that Elia dreads most is being stuck talking to a well-educated man whom he doesn't know, since this is when he has to suffer the agony of confronting his own ignorance in depth. He recounts a time that he was stuck on a coach with one such man, totally unable to carry conversation about show cattle, the Indian market, the songs the Sirens sang, or anything else the man brought up. The conversation ended mercifully only once the man got off the coach. Once getting off the coach, the man was able to start talking of local epidemics, and seemed pleased. Elia quickly realized this man was a schoolmaster, explaining his endless thirst for knowledge, and begins to reflect on the difference between new schoolmasters and old ones.
Old schoolmasters were concerned only with what could be taught within the limits of their language. They would delve into literature and ancient languages which informed their present one, but cared little about much that fell outside the purview of grammar. New schoolmasters, note Elia, are people who have cast stores of knowledge across a broad range of subjects, since they don't want their students to be totally ignorant of anything. The new schoolmaster finds opportunities to teach all the time and everywhere, not even passing up the chance to teach something to his students while walking with them through nature.
Elia recounts his restlessness as a child, his inability to ever feel totally at ease in the presence of a schoolmaster since the schoolmaster is never fully at ease in the presence of children. The schoolmaster is never allowed to let his intellect loose, always trying to read children and cultivate teachings to impart to them. He closes he essay with an excerpt of a letter from a schoolmaster who speaks of the burden of expectation by children on the schoolmaster, who, even when he lost his wife, was not able to bridge the gap of being his students' mentor, but rather was further isolated in the role, unable to get them to appreciate his existence as a mere man whose wife has died unfortunately and prematurely.
Like all of Lamb's finest essays, "The Old and the New Schoolmaster" starts with one tone and ends with a totally differently one. Similar to "Dream Children," this one starts out light-hearted but veers into the fatalistic, articulating loneliness and a kind of pain that is essential to the human condition. The essay opens with self-deprecation, as Lamb explores the shortcomings of his education and his intellectual limitations, and ends with a schoolmaster mourning his lack of opportunity to explore his own humanity around his students. On one hand, we have Lamb talking about limitations he feels by way of personal ignorance and, on the other, we have the schoolmaster talking about limitations imposed on him by the very people whose ignorance he is tasked with curbing.
This mirror structure serves as mechanism of parallelism between two unlikely people. Early in the essay, Lamb contrasts himself with better-educated men, talking about how much he dreads encountering their wealth of knowledge. But by the end of the essay, we find him drawn to one of those educated men. They parallel each other not through education or ignorance, but through their respective isolation from the world around them. This move demonstrates Lamb mastery as a storytelling, drawing us in with humorous self-deprecation but keeping us on the hook to learn something about the nature of human experience in a modernizing society.
That modernization is the subtext of "The Old and the New Schoolmaster," as Lamb concerns himself with a society that's changing around him. He looks at the younger generation, seeing how they're educated, and reflects on his intellectual shortcomings rooted in his own upbringing. We sense that the schoolmaster's sense of isolation in the letter comes partly from the confusion of having to navigate a shifting world while grieving. All of this expectation is placed on him to enlighten his students—demanding that he build an intellectual bond with the boys as a polymath mentor—while the realities of the alienation between schoolmaster and schoolboy have never changed.