What constitutes a work of classic literature? T. S. Eliot, in a 1944 address to the Virgil Society in London, argued that a classic could be defined by its “maturity.” “A classic can only occur,” he maintained, “when a civilization is mature; when a language and a literature are mature; and it must be the work of a mature mind.” Yet it is not exactly clear how Eliot, in his prickly way, defined maturity. “We cannot call the literature of the Elizabethan period, great as it was, wholly mature,” he continues, neatly dismissing Shakespeare and Marlowe in one fell swoop.

Mark Twain, in a speech delivered at New York’s Nineteenth Century Club 44 years earlier, took a more humorous approach to this question. A classic, he quipped, is “something that everybody wants to have read and nobody wants to read." It is easy to imagine the audience laughing self-deprecatingly, and it’s a quote, originally attributed to a professor at Wesleyan University, that still gets repeated today. But while Twain’s observation may be funny—and partially true—there’s also something unsatisfying about it. After all, there are a whole host of reasons why certain books endure, even those that have, like Melville’s Moby-Dick orthe writings of Kafka, been dismissed, ignored or poorly reviewed during their authors’ lifetimes.

While fashions in literature come and go, there is something attractive in the idea of a canon—if nothing else as a means of quality control when deciding what to read next. Perhaps this is why Morrissey, the musician and ex-frontman of the Smiths, insisted that his autobiography be published by Penguin’s famous Classics imprint (Penguin justified its acquiescence by arguing that Autobiography was “a classic in the making”). At the same time, those who decide a canon’s scope have wielded the term “classic” as though it were a weapon, allowing only a narrow swath of individuals from certain groups to be elevated to its place. Because of this, in recent decades there have been arguments in favor of what is called an “expanded canon,” which makes space for writers who are women, or not white, or who work in non-European languages.

So, what does make a classic? Perhaps the best definition came from the Italian writer Italo Calvino in his 1981 essay on the subject: “A classic is a book that has never finished saying what it has to say.” It’s a book that is deeply engaged in a conversation that spans decades, countries, classes and creeds; a conversation that can otherwise be simply called “literature.”¹ And to engage with this discourse, you don’t need to be a certain type of person. You simply need to be curious enough to pick up a book.