Most students begin by being very skeptical of the notion that there are "hidden meanings" in literature. This resembles a very wise logical rule called "Occam's razor," after William of Occam (or Ockham), the 14th-century monk who used it in logical debates about the metaphysics of angels and salvation. "Occam's razor" says that, when trying to explain something, we shouldn't unnecessarily multiply the number of invisible entities necessary to make it happen (e.g., angels, demons, aether, deans, etc.). The principle is an outgrowth of Aristotelian thinking that emphasizes the study of the material world using rational interpretations of independently verifiable phenomena.  So we want words to mean what the dictionary says they mean for very good reasons.  However, there are several other good reasons why literature might contain hidden meanings, that is, meanings that are not readily obvious to the casual reader and that can't be found in ordinary dictionaries.

        These two common types of "hidden meaning" are the products of the author's clear intentions and often can be found by close reading of the text, with no necessary need for additional historical background.

Literal sense vs. figurative sense:

        First, one must be sure one understands the literal sense of what the author meant to say as well as one can based on competent reading. That sounds simple, but here are some ordinary ways of using language that complicate and even hide meanings. My simple statement that "Zoe is a cat" could mean nothing more than that one of my four-legged feline companions is named for the Greek word, "life." However, if Zoe is a human in the 1950s, I might mean that she is a female jazz musician or one knowledgeable about music and culture—"cat" or "hip cat' was a 1950s beatnik metaphor for "one who was observant, wise, stealthy, and quick to detect the latest trends" like a cat is sharp in its watchfulness and sophisticated in its movements. If I used the word today, I might be indicating that she styled herself after the 1950s: wore black turtlenecks and dark eye shadow, smoked imported cigarettes, and studied philosophy and cinema. There's also a sense in which "cat" can be a negative attack on a woman quick with words and gossip, as in "catty." Already we're edging away from obvious, literal meanings and bending language in many ways.  Those "bent" ways are usually called "figurative speech," after the classical rhetorical terms for figures of speech which shift words meanings in predictable types of ways.

The author's deliberately disguised meanings:

        We read obviously double or triple meanings every day in the forms of irony and sarcasm, which over- or under-state the author's real meaning ("Would you wake me when class is over?"). In literature, we can see it in Aeschylus' Agamemnon when Clytemnestra sings a hymn of praise for her husband's safe return from the war (so she can kill him in revenge for his killing of their daughter, Iphegenia). "Dramatic irony" doubles meaning by putting a literally unambiguous statement or action into a context which overcomes its meaning, as when Sophocles' Oedipus first limps onto the stage to proclaim he will solve the murder of the king of Thebes, not knowing that the injuries to his feet (his name means "swollen foot) were directly linked to the prophecy that he would murder that man.

        Furthermore, authors seem to delight in multiplying structural features of their works to embellish their beauty, and in placing small references to other works within them so as to code the finished piece of literature with "hyperlinks" to related ideas and to other works of literature. This kind of self-aware multiplication of meaning can take the form of thematic repetition and parallels in plot or language (Odysseus' two shipwrecks, Jane Eyre's "two suitors," Thomas Pynchon's use of ballistic arcs as plot structures in Gravity's Rainbow; Joyce's patterning a Dublin day on the books of the Odyssey, Sylvia Plath's use of ancient Welsh bards' phrasing in her lyrics). Such clues reward more curious readers, the patient ones more willing to spend time with the work. More importantly, it packs more wisdom into the work, linking it ever tighter to the whole tradition of literary creation. Poets want their work to last, forever if possible. Creating multiple layers of meaning within it, and grafting it to earlier great works, makes it richer and more durable, more likely to be read for its own sake and for works it relates to..

                The preceding kinds of meaning are deliberate products of the authors' intentions. There are others which are not necessarily consciously intended, but are artifacts of creation, like fingerprints on a gun, fossil tree rings, or carbon-14 percentages, which tell us things about how and when the work was made. That information also "means things," though those meanings are not necessarily willed by the author.  These meanings require the student to learn about the past, including the history of the language.  An important reference for this is the Oxford English Dictionary, and its spin-off, the Middle English Dictionary, which record words chronologically from their first appearance in a surviving text and chart the changes in the words' meanings over time.  An even more precise estimate of an author's personal English may be obtained by examining her/his use of the word in all her/his works by looking it up in a "concordance,"  a personalized dictinary from "A" to "Z" of every word an author ever wrote, linked to passages in context.

Socially or psychologically coded or concealed meanings:

        Every culture has values, expressed in a coded vocabulary ("liberal," "honest," "noble") which changes over time. Works produced at a time when such values are stable use the words in stable ways, but when values are in flux the terms become unstable, often dividing into two or more usages (Middle English "trouthe" later splits into "truth" [what is] and "troth" [a promise to make it so]).  Psychological stresses can distort usage, something writers take advantage of in dialogue when a character obsessed (love/hate) with another character will talk about him/her at inappropriate intervals or forget to name him/her, assuming all feel the same and are thinking about the object of the obsession as often as the obsessed does. Action can reveal psychology too, as when a blush, stammer, or interrupted speech indicates guilty knowledge or deeply engaged affections.

        Authors, themselves, also sometimes reveal things about their own psychological states when they cannot fully control their material. Insecure authors may unconsciously overcompensate by building the work too full of connections to previous high art without fully mastering the relationship. Overconfident authors may fail to fully develop a work's characters or plot. Sexist or racist authors (and here we have to be honest about our own weaknesses) may unconsciously or intentionally reproduce common prejudices they expect their readers to share.   Sometimes, it's hard to tell whether an author intends the revelation of such emotionally charged attitudes.  The notoriously difficult satire of Huckleberry Finn, for instance, contains the following shocking exchange which perfectly illustrates the inhumane mentality of America's slave-owning past: Huck reports to an Alabama housewife that a steamboat's boiler has blown up and, in reply to her asking whether "anyone was hurt," Huck innocently replies "No ma'm--killed a nigger, though."  Mark Twain's 1874 audience was already deep in denial about a slave-owning past that was only ten years old, and it can be argued that he meant to burn slavery's memory into their consciousnesses, but it is easy for the historically unaware reader to read Huck as evidence of Mark Twain's racism.  This kind of interpretive problem is what makes interpretation difficult and important.  Our own prejudices usually are invisible to us, but they're easier to detect when those prejudices are from a previous era (e.g., colonial America or 5th-century BCE Athens) or in a social subgroup to which we don't belong (e.g., rap music, performance art, college professors). Rather than merely condemning the faults or dismissing the entire work, a creative reader will use the faults to develop insights about the author's psychology and social surroundigs.

Historical/cultural conditions:

        Even apart from a work's terms for values, it often brings with it the most common intellectual and factual assumptions of the era which produced it in the very materials and methods with which it was made, like a stone-age ax or an Impressionist painting.  We're currently super-sensitized to racial, class, and gender assumptions which often change gradually but with powerful effects.  However, almost every other detail of the work may reveal evidence of the artist's culture.  Forms and content tell us what it was like to be alive at the time of creation, sometimes in surprising ways. As usual, this requires us to ask questions about things we've formerly taken for granted. We can wonder why the English suddenly started writing sonnets in early C16 (an aristocratic fad for Italian culture and tourism?; a strategy for guildsmen's sons to make an artistic reputation?) and why they almost completely stopped writing sonnets in the mid- to late C17 (the Civil Wars left prose-writing Puritans in charge?; the court's return from France brought new lyric forms?). We can ask why, in 1610, Ameilia Lanyer, a commoner, dared to rewrite Genesis to defend women in all times from attack, but in 1680-1713, Ann Finch, an independently wealthy aristocrat, disavowed any high goals for her work and insisted on writing mainly light verse on social foibles. We can ask why, in 1847, Charlotte Bronte gave Jane Eyre two male suitors with such contrasting attitudes about morality, and why the source of Rochester's polluted marriage is several times said to come from West Indies Creole culture.