“To be, or not to be—that is the question:

Whether ’tis nobler in the mind to suffer

The slings and arrows of outrageous fortune

Or to take arms against a sea of troubles

And by opposing end them. To die, to sleep—

No more—and by a sleep to say we end

The heartache, and the thousand natural shocks

That flesh is heir to. ’Tis a consummation

Devoutly to be wished. To die, to sleep—

To sleep—perchance to dream: ay, there’s the rub,

For in that sleep of death what dreams may come

When we have shuffled off this mortal coil…”

— Soliloquy from William Shakespeare’s 1604/5 “Hamlet”

Those poetic lines, not even one full half of Hamlet’s immortal soliloquy, contain phrases that still pepper the English language more than 400 years after they were composed. Yet our perception of the brooding Dane — and of Shakespeare’s insights into human nature — would be drastically different if only the play’s First Quarto (Q1), published in 1603, had survived. Also known as the Bad Quarto, only two copies of it are known to exist; one is housed at the British Library in London, and the other lives at the Huntington Library in San Marino. Under the umbrella of its new President’s Series, and as part of the Huntington’s recently launched centennial celebration, University of Pennsylvania English professor Zachary Lesser will discuss the differences between the two quartos as well as the Bad Quarto’s journey to the Huntington in a lecture at Rothenberg Hall Wednesday, “Hamlet and Other Ghost Stories.” On Thursday, the Independent Shakespeare Co. will illuminate those differences in performance.

“You could argue it’s the most important piece of literature in the English language; many people think it’s the greatest work in the English language,” says Lesser, who dislikes the term “Bad Quarto” because it implies the writing isn’t Shakespeare’s. Theories regarding its origin still rage; some contend it was reconstructed from memory by actors, others say it was faultily transcribed by audience members, and another school of thought maintains that it’s Shakespeare’s first rough draft. There’s plenty there to feed the enduring human hunger for mystery.

Regardless, Lesser’s fascination with Q1 was triggered when he learned how it was discovered in 1823, over 200 years after Shakespeare’s death: by a baronet, Henry Bunbury, who had just inherited his title and was inspecting his new country house library and possessions. By that point in time, “Hamlet” was commonly acknowledged as Shakespeare’s masterpiece and was widely known and quoted.

“The reception of this text (Q1) is colored by that,” Lesser says. “The fact that it’s not discovered until 200 years afterward has everything to do with the way we’ve understood it.”

The core difference between Q1 and the more famous version is length; the Q1 “Hamlet” is approximately half as long, making it faster and more focused on revenge. There’s less debate, more action. Lesser puts a finer point on it: “It’s been said the First Quarto of ‘Hamlet’ is a revenge tragedy, and the famous version of the play is a tragedy about revenge. Which makes some sense, because in the famous version it’s a lot of meditative, philosophical thinking about whether to revenge or not.”

Those differences are not inconsequential considering the play’s lofty position, not just as a hallowed piece of canonical literature but also as an instantly recognized signifier in speech and philosophical rhetoric. Some of those differences will be grist for debate between historical characters portrayed by actors from the Independent Shakespeare Co. during their performance Thursday.

“The famous version of ‘To be or not to be’ is a very existentialist kind of speech; it’s completely skeptical about the afterlife, there’s no mention of God or Christ,” observes Lesser, who plans to identify “interesting patterns” in certain key differences during his lecture. “Hamlet is completely mystified by what will happen after death. He says that it’s this ‘dread of something after death’ that makes people not commit suicide, because maybe what comes after death is worse than the miseries of life. It’s a powerful line because ‘something’ is this nameless unknown. It’s a very un-Christian speech.”

In contrast, the Q1 version is downright conventional, as Hamlet claims that after death we are “taken before the everlasting judge” and the “something after death” is hope of reaching heaven. That is what frightens people away from suicide, which traditional Christian theology defines as a mortal sin that would condemn them to hell.

“The famous ‘Hamlet’ is famous partly because of Shakespeare’s kind of skeptical, philosophical vision of the afterlife that refuses to take for granted what everyone in Shakespeare’s audience would have heard in church on Sunday. It’s a big part of what makes the play feel very modern to us and still timely. We see Hamlet grappling with this mystery of life and death,” Lesser says. “Whereas the Q1 version can feel to us almost like a transcription of what a preacher would say on a Sunday.”

Since the objective of the Independent Shakespeare Co. performance is to entertain, Thursday’s event will be structured around a short original play incorporating certain scenes — including “To be or not to be” and Hamlet’s death scene — from Q1 “Hamlet.” Lesser will join a Q&A afterward.

“I’ve been at a performance of the whole play, and done a talkback kind of thing, but never like this, where it won’t be that long as performing the whole play,” he says. “I’m excited. It will give you a taste for the play itself.”

Zachary Lesser discusses “Hamlet and Other Ghost Stories” in Rothenberg Hall at the Huntington Library, Art Museum, and Botanical Gardens, 1151 Oxford Road, San Marino, at 7:30 p.m. Wednesday, Nov. 13; free but advance reservations required. Independent Shakespeare Co. performs selections from Q1 “Hamlet” at the Huntington’s Rothenberg Hall at 7:30 p.m. Thursday, Nov. 14; free but advance reservations required. Info: (626) 405-2100. Huntington.org