the first critic to ponder the theme of the play, which he saw as the just punishment of the two feuding families. In mid-century, writer Charles Gildon and philosopher Lord Kames argued that the play was a failure in that it did not follow the classical rules of drama: the tragedy must occur because of some character flaw, not an accident of fate. Writer and critic Samuel Johnson, however, considered it one of Shakespeare's "most pleasing" plays. In the later part of the 18th and through the 19th century, criticism centred on debates over the moral message of the play. Actor and playwright David Garrick's 1748 adaptation excluded Rosaline: Romeo abandoning her for Juliet was seen as fickle and reckless. Critics such as Charles Dibdin argued that Rosaline had been included in the play in order to show how reckless the hero was and that this was the reason for his tragic end. Others argued that Friar Laurence might be Shakespeare's spokesman in his warnings against undue haste. At the beginning of the 20th century, these moral arguments were disputed by critics such as Richard Green Moulton: he argued that accident, and not some character flaw, led to the lovers' deaths. Dramatic structure In Romeo and Juliet, Shakespeare employs several dramatic techniques that have garnered praise from critics, most notably the abrupt shifts from comedy to tragedy (an example is the punning exchange between Benvolio and Mercutio just before Tybalt arrives). Before Mercutio's death in Act III, the play is largely a comedy. After his accidental demise, the play suddenly becomes serious and takes on a tragic tone. When Romeo is banished, rather than executed, and Friar Laurence offers Juliet a plan to reunite her with Romeo, the audience can still hope that all will end well. They are in a "breathless state of suspense" by the opening of the last scene in the tomb: If Romeo is delayed long enough for the Friar to arrive, he and Juliet may yet be saved. These shifts from hope to despair, reprieve, and new hope serve to emphasise the tragedy when the final hope fails and both the lovers die at the end. Shakespeare also uses sub-plots to offer a clearer view of the actions of the main characters. For example, when the play begins, Romeo is in love with Rosaline, who has refused all of his advances. Romeo's infatuation with her