Early Shakespeare texts clarify -- and blur; Shakespeare's Plays in Quarto, edited and with introduction and notes by J. B. Allen and Kenneth Muir. Berkeley, Calif.: University of California Press. 906 pp. $95.

In his famous soliloquy on the winter of our discontent, the lame and crafty Richard III describes himself as ''Deform'd, unfinish'd, sent before my time/ Into this breathing world, scarce half made up.''

He might well have been describing the first printed editions of Shakespeare's plays.

In our age of sophisticated printing, we think of first editions as lovingly tended things whose accuracy is insured by the constant care of authors, editors , printers, and proofreaders. In Tudor and Stuart times, it was quite otherwise. Shakespeare himself apparently never oversaw the printing of any of his works. And the theater companies for which he wrote, far from disseminating his works, guarded them jealously from rival companies.

That, however, was not enough to squelch the piratical printers: undeterred by the legal niceties of modern copyright law, they simply sent stenographers into the audiences. They copied the lines as best they could - and sometimes bribed lesser members of the cast to recite the play from memory.

But copiests blunder, and actors mangle, and compositors work in haste. So Shakespeare's ''first editions'' - the quartos, so-called from the printers' tradition of folding large sheets into ''quarters'' of four sheets (eight pages) apiece before binding - are in many cases botched beyond repair.

Case in point: the first quarto of ''Hamlet.'' The Danish prince's sidekicks' names are spelled ''Rossencraft'' and ''Gilderstone.'' And the speeches themselves are hopelessly corrupt. ''To be, or not to be, that is the question, '' says the Hamlet we all know and love. In the quarto he begins ''To be, or not to be, I there's the point'' - and then proceeds to leave out, by the handful, some of the most famous lines in the English language.

Not all the quartos, which appeared individually between 1594 and 1634 for 22 of Shakespeare's plays, are that bad. Some are reasonably pure. So is the collected works, appearing in the 1623 folio edition (a facsimile edition of which is already in print). But neither quartos or folio are authoritative. Establishing a valid text for a single play, then, is a tremendous effort of editorial judgment - involving decisions that can lead right back to the work habits of Elizabethan typesetters, each one of whom tended to spell as he saw fit.

Hence the value of the quartos. Scholars have long had access to them, but only by traveling to the British Museum or the Folger, Bodleian, or Huntington libraries. Now, however, modern photographic processes have made possible the sharp reproductions of original pages in this facsimile edition of copies primarily taken from the Henry E. Huntington Library, which fill this book. A beautiful but odd-shaped publication, it has extra-wide pages designed to accommodate two pages of quarto text side by side. As the editors rightly note in their scholarly and useful introduction, the quartos ''continue to be absolutely fundamental to an understanding of Shakespeare in the study or the theater.'' They and the University of California Press deserve praise for making them more widely available.