The slings and arrows of outrageous fortune: everyone knows the phrase. And most people know where it’s from: “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 . . .”

What does it actually mean? Something about being buffeted by bad luck and worldly troubles, obviously. But the image is curious. Fortune, who dishes out our luck, is traditionally personified as a woman. If she has arrows, shouldn’t she have a bow rather than a sling? Why didn’t Shakespeare write: “The bow and arrow of outrageous fortune”? Or for that matter, “The slings and stones of outrageous fortune”?

Shakespearian commentators have puzzled over this conundrum for centuries, even going so far as to suggest that the inconsistency of weapon may mean that “slings” is a printer’s error for “stings”. Now, however, we have a solution. Almost every book written in the age of Shakespeare has been made available in digitised form. So you can go to an amazing website from the University of Toronto called Lexicons of Early Modern English and type in the word “sling”. Within a second the search engine will have worked its way through more than 150 dictionaries, glossaries and word lists from the 16th and 17th centuries.

Up pops a citation from Randle Cotgrave’s A Dictionary of the French and English Tongues (1611), the first English-French dictionary: “Mangonneau: An old-fashioned sling, or engine, whereout stones, old iron, and great arrows were violently darted.”

So arrows can be fired from a sling. Fortune doesn’t have a puny little hand sling — rather she is firing off a huge catapult, a mighty engine of siege warfare. Hamlet’s image in this line is as strong as that in the next, where the hero imagines battling against an entire sea of troubles.

In The Merry Wives of Windsor, Falstaff is repeatedly tricked into being caught in the house of Mistress Ford when her sexually possessive husband comes home. The first time he is bundled out in a basket of dirty linen, the second he escapes in the disguise of “the fat woman of Brentford”.

Brentford (spelt Brainford in Shakespeare’s time) was then still a village on the road from London to Windsor. But why did Shakespeare choose to give the place a name-check? Type it into an online database of every surviving play from his time and you discover that Brentford was a favourite location for sexual assignations. A modern equivalent would be a reference to “round the back of King’s Cross”.

These are just two examples of how we are still making new discoveries about Shakespeare’s amazingly inventive language. Traditionally editors have glossed his more obscure words by taking a definition from the Oxford English Dictionary. But in many cases the Oxford English Dictionary has come up with its definition by simply looking at the example in Shakespeare. The new online databases allow us to break out of this loop. They show us that many words purportedly coined by Shakespeare were actually in wider currency at the time, but they also make new revelations about the associative power of his imagination.

“Do we really need another new edition of Shakespeare?” people ask me when I tell them that, together with my team of associates, I’ve devoted nearly 20 years to the preparation of the new RSC Shakespeare: Complete Works. The new possibilities for exploring his language are one reason why we most certainly do.

Another is the astonishing fact that no edition in the past three centuries has consistently adopted the text of the most authoritative original version of Shakespeare’s plays: the 1623 First Folio (so named for the large size and single fold of its paper) prepared by his fellow actors John Hemings and Philip Condell. How on earth has this state of affairs come about?

The scholarly editing of Shakespeare began in the 18th century, when the model for such activity was the treatment of the classic literary and historical texts of ancient Greece and Rome. The procedure was to establish which surviving manuscript was the oldest, the aim being to get as close as possible to the lost original, weeding out the errors of transcription that had been introduced by successive scribes in the centuries before the advent of print. As Shakespeare began to be treated like a classic, the same procedure was applied to his texts.

About half of Shakespeare’s plays appeared in print in his lifetime in quarto format, cheap little books analogous to the modern paperback. Following the classical principle that the earliest surviving text must be the one closest to the original authorial manuscript, generations of editors preferred the quarto texts to the posthumously produced folio — save in a small number of cases where the quarto text was so full of errors and inconsistencies that they had to rely on the folio.

For this reason, all edited texts of the complete works published in the past three centuries have been hybrids of quarto and folio, scholarly reconstructions that merge together different moments in the original life of many of the plays.

If you look at printers’ handbooks from the age of Shakespeare, you quickly discover that one of the first rules was that, whenever possible, compositors were recommended to set their type from existing printed books rather than manuscripts.

This was the age before mechanical typesetting, where each individual letter had to be picked out by hand from the compositor’s case and placed on a stick (upside down and back to front) before being laid on the press. Printers’ lives were a lot easier when they were reprinting existing books rather than struggling with handwritten copy.

Easily the quickest way to have created the First Folio would have been simply to reprint those 18 plays that had already appeared in quarto and only work from manuscript on the other 18. But that is not what happened. Whenever quartos were used, playhouse “prompt books” were also consulted and stage directions copied in from them. And in the case of several major plays where a well-printed quarto was available (notably Hamlet, Othello, Richard III and Troilus and Cressida), the folio printers were instructed to work from an alternative, playhouse-derived manuscript.

This meant that the whole process of producing the first complete Shakespeare took months, even years, longer than it might have done. Hemings and Condell wanted “the great variety of readers” to work from texts that were close to the theatre life for which Shakespeare originally intended them.

The Shakespeare First Folio is one of the iconic books in the cultural tradition of the West — indeed, given Shakespeare’s unprecedented international reach, of the world — but such is the conservatism of scholarly tradition that it has taken three centuries for it to be properly edited as a book in its own right and for the practice of mixing quarto and folio copy texts to be challenged.

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