Ultimately of course Theobald came under severe attack by succeeding editors of Shakespeare, notably Warburton and Johnson, yet both men were guilty of unwarranted abuse of their predecessor, whose edition was nine times issued in the course of the century and was still in current use by the time of Coleridge (cf.  Wm. Jaggard, Shakespeare Bibliography, 1911, pp. 499-504).  Warburton and Johnson’s abuse, coupled with that of Pope, obscured Theobald’s real achievements for more than a century until J.C.  Collins did much to rehabilitate his reputation by an essay celebrating him as “The Porson of Shakespearian Criticism” (Essays and Studies, 1895, pp. 263-315).  Collins’s emotional defense was largely substantiated by T.R.  Lounsbury’s meticulous The Text of Shakespeare (1906), R.F.  Jones’s Lewis Theobald (1919), which brought much new material to light, and most recently by R.B.  McKerrow’s dispassionate appraisal, “The Treatment of Shakespeare’s Text by his Earlier Editors, 1709-1768” (Proceedings of the British Academy, XIX, 1933, 23-27).  As a result, so complete has been Theobald’s vindication that even in a student’s handbook he is hailed as “the great pioneer of serious Shakespeare scholarship” and as “the first giant” in the field (A Companion to Shakespeare Studies, 1934, ed.  H. Granville Barker and G.B.  Harrison, pp. 306-07).

Theobald’s Preface occupied his attention for over a year and gave him much trouble in the writing.  Its originality was, and still is, a matter of sharp dispute.  The first we hear of it is in a letter of 12 November 1731 from Theobald to his coadjutor Warburton, who had expressed some concern about what Theobald planned to prefix to his edition.  Theobald announced a major change in plan when he replied that “The affair of the Prolegomena I have determined to soften into a Preface.”  He then proceeded to make a strange request: 

But, dear Sir, will you, at your leisure hours, think over for me upon the contents, topics, orders, &c. of this branch of my labour?  You have a comprehensive memory, and a happiness of digesting the matter joined to it, which my head is often too much embarrassed to perform....  But how unreasonable is it to expect this labour, when it is the only part in which I shall not be able to be just to my friends:  for, to confess assistance in a Preface will, I am afraid, make me appear too naked (John Nichols, Illustrations of the Literary History of the Eighteenth Century, 1817, II, 621-22).

His next letter, which contains the list of acknowledgements substantially as printed, thanks Warburton for consenting to give the requested help, announces that he is himself busy about “the Contents... wch.  I am Endeavouring to modell in my Head, in Order to communicate them to you, for your Directions & refinement,” indicates that he has “already rough-hewn the Exordium & Conclusion,” and asserts that “What I shall send you from Time to Time, I look upon only as Materials:  wch I hope may grow into a fine Building, under your judicious Management” (Jones, op. cit., pp. 283-84).