The description of MacBeth mentions characters "Ridinge", a detail that critics with a knowledge of Jacobean dramaturgy and stagecraft had found startling,[4] although subsequent scholars, commenting on a horse evidently present on stage in another play, have opined that it is within the realm of possibility.[5] Also the idea that Forman, a worldly-wise and canny operator, would spend his time drawing sententious morals from the stage plays he saw struck some modern critics as psychologically false, and in the 20th century suspicion emerged that the Book of Plays was one of John Payne Collier's forgeries, although Collier, who announced his discovery of the document in 1836, claimed to have used a transcription made for him by an unnamed "gentleman" (identified in 1841 by James Halliwell as William H. Black, who catalogued the Ashmolean Collection).[6]
In 1933 Samuel A. Tannenbaum published an elaborate case arguing that the section was a forgery. Much of Tannenbaum's case centered on palaeographic arguments about the manuscript's handwriting.[7] An earlier examiner of the manuscript had transcribed the section title as "A Book of Places", and Tannenbaum theorised that the section originally contained descriptions of places in England that Forman had visited and that Collier had altered the title and either inserted forged leaves or had chemically removed the ink for his forgeries. However, subsequent scholars examined the leaves under ultraviolet light and found no trace of forgery or rebinding. In 1945, W. W. Greg criticised Tannenbaum's scholarship and J. Dover Wilson and R. W. Hunt both examined the manuscript without finding any evidence of tampering. It was also learned that Tannenbaum, who had not examined the manuscript but relied instead on photostats, had compared the section with writing Forman had done ten years earlier instead of using a control from the same period. Finally, the record Halliwell had found identifying Black as the librarian that had made a transcript of the Forman manuscript for Collier in 1832 was rediscovered, confirming that Collier never had access to the manuscript.[8] Most modern scholars accept the section as authentic,[9] but some still suspect it might be a forgery.[10] Katherine Duncan-Jones, for example, did not use it as a source for her biography of Shakespeare, finding it "strangely suspicious that Forman, who nowhere else in his copious papers reveals any interest in the theatre, should suddenly have taken to playgoing in the last year of his life",[11] apparently unaware that Forman does reveal an interest in theatre elsewhere in the manuscripts.[12]