Restoration theatre theory, polemic, and practice are closely concerned with questions of value, although they have received little attention in recent criticism that considers the formation of the English canon up to and during the eighteenth century. The main issue addressed concerns the legitimacy of dramatic form, which dominates the metatheatre of 1668–75, but also appears unexpectedly in the political drama (especially the comedy) of the early 1660s and the antitheatrical rhetoric of the 1690s. In all these instances, the complexity, integrity, and completeness of drama-in-performance are seen to determine the value of plays as well as playwriting. While the attack on heroic drama in metatheatrical plays such as Shadwell's The Sullen Lovers (1668) and Buckingham's The Rehearsal (1671) is directed by authors of one persuasion against another, Thomas Duffett's burlesque attack on the theatre of spectacle in the 1670s paradoxically is reinforced by the self-criticism of his targets. Moreover, Jeremy Collier's antitheatrical offensive in the late 1690s shows an atypical concern with specific dramatic content, especially in comedy, suggesting that both metatheatre and antitheatre in the Restoration focus their oppositional energies on the particulars of genre.