I first came across this question today on Ian Speere's website at http://www.realshakespeare.com/the-authorship-question/nashe. After further searching, I also found it in an unanswered comment by Rita Lamb on The Forest of Arden on a 2011 thread, and lastly in Ros Barber's book Shakespeare: The Evidence. This general lack of attention surprises me, because Harvey's words strengthen the case that William Shakespeare might have been known to a small group of writers (who held this as a closely guarded secret) as a front man for an aristocratic poet.
By way of background for those who haven't encountered this question before:
In 1593, the English writer Gabriel Harvey published the pamphlet Pierce's Supererogation, an attack on "Pierce Penniless" (the satirist Thomas Nashe, who repeatedly attacked Gabriel Harvey in print during the 1590s) and "Pap Hatchet" (the writer John Lyly). Harvey chose the pseudonym "Pap Hatchet" as a nod to Lyly's 1589 pamphlet Pap With a Hatchet, which attacked the pseudonymous pamphleteer Martin Marprelate (a vociferous critic of the Church of England) and his fellow "Martinists." Pap With a Hatchet also included some cutting remarks about Gabriel Harvey, and is the main source of Harvey's wrath against Lyly.
From an authorship perspective, the most interesting aspect of Pierce's Supererogation is Harvey's claim to know a great secret concerning a "rich mummer" (most likely a wealthy actor, since the word 'mummer' meant either an actor who wore a mask or costume in a pantomime, or a generic actor in the archaic use). This secret, if revealed, would "dismask" (expose the hidden truth about) the actor/mummer before the English public. If Harvey were to reveal all that he knew, his pamphlet would immediately become a bestseller ("the veniblest book in London"), and he himself would become "one of the famousest authors in England." But Harvey was too discreet to reveal the secrets of a "respective acquaintance," who--due to his social prominence and some private considerations--would not wish the social embarrassment of having his coat of arms blazoned before the world, or the contents of his satchel (typically a bag filled with private papers and books) revealed.
In full, the relevant passage from Pierce's Supererogation reads:
Pap-hatchet talketh of publishing a hundred merry tales of certain poor Martinists: but I could here dismask such a rich mummer, and record such a hundred wise tales of memorable note, with such a smart moral, as would undoubtedly make this pamphlet the vendiblest book in London, and the Register one of the famousest authors in England. But I am none of those that utter all their learning at once: and the close man (that was no man's friend but from the teeth outward, no man's foe but from the heart inward) may percase have some secret friends, or respective acquaintance, that, in regard of his calling, or some private consideration, would be loath to have his coat blazed, or his satchel ransacked.
In an elliptical fashion, Harvey links the unmasking of the wealthy actor/mummer with a major revelation concerning a socially preeminent man bearing a coat of arms. There is no sense that Harvey's secret knowledge regarding the gentleman bearing the coat of arms would reflect poorly on the gentleman's character and integrity. Instead Harvey declares that he could reveal "a hundred wise tales" with "a smart moral." He further indicates that the socially prominent man would only be loath to have his secret or secrets disclosed to the public because of his important position in society ("his calling"), or for private reasons of his own.
As interpreted by the independent Shakespeare scholar Ian Steere (a Stratfordian; see http://www.realshakespeare.com/the-authorship-question/nashe), Harvey is effectively saying: "I have lots of scandalous information concerning a rich actor and a high-ranking person (with a heraldic coat of arms), which would make this pamphlet a best-seller and me famous - but I am too discreet and too loyal to tattle."
Steere continues: "Could Harvey here be referring to Shakespeare as the "mummer"? ...The prosperity of actors relative to that of scholars was a matter deplored by the latter in a number of writings of the time. To them "rich mummer" would be an apt, if derogatory, description."
Steere's theory is that Harvey meant to allude to the story depicted by the Sonnets of an adulterous actor and his dark mistress, both intimately involved with an aristocratic young man. However, when I read Harvey's words, I have a hard time thinking that he had a sex scandal in mind. As previously noted, his reference to a satchel being ransacked calls to mind a scholars' bag, associated with scholarly papers, writings, manuscripts, and books. The implication is that Harvey knew the prominent gentleman held secrets in his satchel--in other words, he could have been a hidden writer. Also, Harvey believes that revealing his secret would "dismask" the actor in the eyes of the public. While a sex scandal involving the actor would be titillating, in what way would it lead to the actor's unmasking? Harvey evidently believed that he knew something about the actor that, if exposed, would reveal him to be a fraud of some sort.
Harvey's words are fully consistent with an alternative Shakespeare authorship scenario in which William Shakespeare served as a front man for a hidden aristocratic author--a secret known only to elite members of the London literati, and that would have shocked the London public if it came out. (This would be especially true if the hidden author were Thomas Sackville, a privy councilor and Queen Elizabeth's second cousin.) And Harvey's words require him to have known a secret bombshell revelation involving the dismasking of a wealthy mummer and the metaphorical or real contents of a socially preeminent man's satchel.
I should add, Rita Lamb and Ros Barber provide entirely different interpretations of Harvey's words than my own interpretation, or that of Ian Steere.
Rita Lamb's theory from a 2011 thread at The Forest of Arden (https://groups.google.com/forum/#!topic/ardenmanagers/OuyFfZeRI-I)
"This passage is entirely about Harvey's old academic enemy
Dr. Perne. Perne sabotaged Harvey's bid for the oratorship in
1579. Outwardly calm and imperturbable he always had his
own agenda, and kept his real thoughts very secret. Harvey
found him unfathomable, 'the close man'. He also suspected
him of slyly appropriating public funds; so he was a 'rich
mummer' - a wealthy deceiver. Harvey also sensed many
might feel he shouldn't reveal Dr Perne's scandalous faults
'in respect of his calling' - Perne was Dean of Ely. And so on.
This is long-winded and anyway, you can read the passage
for yourself. Harvey begins to allude to Perne at 'I could
nominate the man that could teach the Delphical oracle, and
the Egyptian crocodile, to play their parts.'"
I find Lamb's theory to be unlikely in the extreme. The term "mummer" did not mean a "deceiver," it meant an actor in pantomimes, or an actor in general. Also, why on earth would some old gossip about the little-known academic Dr. Perne be of sufficient interest to make Gabriel Harvey think that he knew a huge secret about a rich mummer that could make his book a bestseller among the London public, and himself famous as the revealer of this secret? Harvey thought he had a major revelation on his hands, and I can't see Dr. Perne as being important enough to qualify.
The only other theory I've been able to track down so far concerning Harvey's "rich mummer" is that of Ros Barber. In Shakespeare: The Evidence, she argues that when Gabriel Harvey wrote the following line:
"...I could here dismask such a rich mummer, and record such a hundred wise tales of memorable note, with such a smart moral, as would undoubtedly make this pamphlet the vendiblest book in London, and the Register one of the famousest authors in England...,"
he did not use the term "this pamphlet" to mean his *own* pamphlet, Pierce's Supererogation (registered on April 27, 1593). Instead, she maintains that Harvey meant to refer to William Shakespeare's slim poetry volume Venus and Adonis (registered on April 18, 1593). According to Barber, Harvey was indicating that if he wanted to, he could reveal the secret of the author of Venus and Adonis's identity. Barber also finds it significant that elsewhere in the same section of Pierce's Supererogation, Harvey uses the phrase "I write only at idle hours, that I dedicate only to idle hours." She interprets this as an allusion to the use of the phrase "idle hours" in Shakespeare's dedication to Venus and Adonis. However, I find it more likely that the term "idle hours" was a common phrase meant to indicate that the author wanted his writing to be seen as frivolous, a toy, not meant to be taken too seriously or to imply a lack of gravitas on the author's part.
I find Barber's argument to be overly convoluted, and too much of a logical stretch. When Harvey talks about "this pamphlet," it seems fairly obvious to me that he is talking about his own pamphlet. And when he refers to the possible Register of the pamphlet becoming one of the famousest authors in England, should he choose to reveal his secret knowledge, it seems most likely to me that Harvey is using round-about language to refer to himself as the potential "Register," or author, of a shocking pamphlet that could make him much more famous -- but that he doesn't actually intend to register with the Stationers' Company.
Whatever secrets Gabriel Harvey knew and withheld from London's reading public in 1593, and whether or not these secrets had anything to do with a Shakespeare authorship question, I continue to be fascinated by how many writers of the period alluded to authorship deceptions, literary fraud, literary mimicry, plagiarism, major hidden poets, and the like, while carefully avoiding revealing the names of anyone involved.