To understand why essay writers sometimes use present tense, and why other times they need to use the past tense, we first have to sort out the meanings of “literal” and “literary.” Granted, these days, people like to use the adverb “literally” in a non-literal way (“Like, I was literally on Cloud Nine!” or “The play was so dull we almost literally died from boredom”). Let’s forget about the sad irony of such usage for now and focus on the literal distinctions between “literal” and “literary.”
Both of these words derive from the same Latin word for “letter,” from which also comes the word “literature.” (Actually, the French term, belle lettres, “beautiful letters,” is still used to refer to what’s now more commonly known as “creative writing.”) However, some literature is written to document or record the facts, and other literature is written as an act of imagination or speculation.
When something is written to be taken “literally,” it uses a factual tone and asks readers to examine its text “in reality.” When something is written to be taken as “literary,” it uses a tone that may be virtually like reality, but which is intended to appeal to imagination. Verb tenses, then, are used by academic writers to reference the literal as separate from the literary.
The literal tense, also known as historical past tense, is used to refer to events and actions that have actually taken place—not in the mind or in the virtual environment of a book or painting, but in a “real” chronology. Take, for instance, the following Wikipedia entry for the novel Ulysses by modernist author James Joyce:
In this example, why does the writing predominantly use past tense in the first paragraph, but present tense in the second paragraph? Because the first paragraph is about the historical reality of the book’s writing, its publication, and its critical reception. These actions and events took place in real time. They are historically factual. In other words, they are literal. However, the second paragraph moves to a discussion of what’s inside the text, and, before we discuss why that’s different, we should first clarify what we mean by “text.”
Anything that has representational content (e.g., an essay; a poem; a documentary; a sculpture; a ballet; etc.), is a text; here, “representational” refers to the use of media, language, or other method to mean something else. When you pick up a magazine and read about what’s going on in the world, you’re not literally in the midst of those events (usually), but, rather, imagining them through the medium of the magazine and the written word on the page. You experience these issues and events, not in the literal realm and its chronology of real time, but in the figurative realm and its timeless landscape of the mind. Sci-fi fantasy time travel escapades notwithstanding, that which happened, for real, happened, and it’s not going to happen again and again in precisely the same way. Victorian poet John Keats even addressed this in one of his most famous poems, “Ode On a Grecian Urn,” where, among the urn’s static depictions, the trees "cannot shed / [Their] leaves, nor ever bid the Spring adieu; / And, happy melodist, unwearied, / For ever piping songs for ever new.” “Static” is the operative word here. That which happens in the representational universe of a text is static; it happens in a perpetual “now” of virtual mind-space, and, for that same reason, can happen again and again, any time you care to revisit the text.
In a roundabout way, then, this explains why we favor the use of literary present tense to talk about the content of a text, and the historical past tense when we refer to events that actually happened in time. Regardless, many writers make the (understandable) rookie mistake of using past tense verbs to refer to the content of a text. For instance,
If you are the kind of person who takes the literary landscape of a book like Alice Walker’s The Color Purple to be a factual biography of someone’s life, instead of a work of fiction, you might be tempted to use historical past tense in this way. In fact, well crafted texts—whether books, movies, art, etc.—successfully draw us into their virtual realities and make us feel like they’re historically “real,” so maybe this is why people mistakenly use the past tense when they write about content such as this. They felt as if they were there. This is only a speculative act, though. You can, if you want, reread Walker’s book, or see the story adapted to Steven Spielberg’s film, then re-watch that. When you close the book or finish the film, the story returns to some unseen guff of “now-ness,” waiting to be experienced again.
That attitude about the timelessness of the texts we experience is essential to the verb tenses we use to discuss them and reference them. The content of a text exists within the timeless realm of the mind, and this requires us to think of it always in the present tense. The creation of a text, however, occurred as an historical fact, and this requires us to reference it in the past tense. Here’s another version of the Alice Walker example to help illustrate this:
Although verb tense and mood are more complicated than having to choose between past and present conjugations, generally speaking, you should always use literary present tense when your writing discusses the content of another text or is otherwise engaged in abstract thinking.
Another confusion about verb tenses can occur when you're writing about the lives, the writing, and the ideas of people who are still alive. Those who have passed "boldly into that other world, in the full glory of some passion," as James Joyce wrote in "Dubliners," are easy enough to discuss in the past tense because they're a closed book. Living entities, however, continue to participate in the discourse of ideas while they have completed contributions in the past. For instance, as of the writing of this guide, theoretical physicist Stephen Hawking is still very much alive. Which of the following would be correct in its verb tenses if you were to write about Stephen Hawking today?
They are all correct. What Stephen Hawking did as part of his illustrious career should be referred to in the past tense. What Stephen Hawking is or believes as a living, thinking, vital member of the human race should be honored in the use of the present tense.
So it goes when you're writing about authors and the content of their published work: when you're writing about what authors believe or what truths they live while they're still alive, you need to use the present tense, but when you're referencing what an author accomplished during his or her lifetime, then you must use the past tense (or a preterite/perfect verb tense).
And—yes—I literally mean every word of this.