-->-- Lucius Accius
One argument is the metaphoric Epigram 221(s.above): The historical tragic poet Accius stands for "telling the truth" (a soothsayer) by way of Tarquin (the poetic personification of Marlowe), the main actor in Shakespeare's Lucrece(1594), who had raped Lucrece (...committed a crime [treason] against Queen Elisabeth ).
Tarquin's alias Marlowe's life was saved, but he had to give up his identity ("forthwith cut in two"), a situation which is compared with "cutting a whet-stone with a razor", an unimaginable matter, [usually it's the other way round, a whetstone sharpens the razor, here there razor cuts the whetstone ), an incredible "inverse" truth! Nobody will ever believe, that this is possible -
It s precisely the metapher for the "The Shakespeare Authorship Enigma".- Since nobody will ever believe this truth, (that Marlowe's identity was cut) the author concludes that it's perhaps better to leave sometimes some truth untold .- Some who want to convey this truth to the world, will inevitably be "hold for liars" (nowadays "conspiracy theorists").