Are there three Hamlets in the three early texts of Hamlet?

This is a conference paper. The following thoughts arise from a book that I am writing on the twentieth-century history of editorial theories in respect of Shakespeare. The New Bibliography that emerged from the work of A. J. Pollard, W. W. Greg, and R. B. McKerrow in the first decades of the century assumed a relatively unproblematic application of Platonic idealism for the relationship between the play as conceived in the mind of the dramatist and the play as performed or written down. Such idealism has in recent critical work (especially from the schools of New Historicism and Cultural Materialism) become decidedly unfashionable and associated with political conservatism. Coming to textual theory from the angle of Marxist ecocriticism, I wish to rehabilitate Platonic idealism as a reasonable way to unite progressive literary scholarship with the latest work in cognitive science. As any materialist must accept, ideas have a basis in the organization of matter in the human mind--ideas are to that extent physically real--and the new scientific studies of consciousness (especially memetics and the 'multiple-drafts' model of cognition) show that the Platonic analogy provides a good way to conceptualize the distinction between the play as abstract thought and its various extant physical embodiments in manuscript and print textualisations