Of a very different order is the important critical treatise which comes next, Dryden's _Essay of Dramatic Poesy_, to which are prefixed as prolegomena Dryden's _Dedicatory Epistle to The Rival Ladies_, Sir Robert Howard's _Preface to Four New Plays_, and, as supplementary, Howard's _Preface to The Duke of Lerma_, and Dryden's _Defence of the Essay of Dramatic Poesy_. As Dryden's _Essay_, like almost all his writings, both in verse and prose, was of a more or less occasional character, it will be necessary to explain at some length the origin of the controversy out of which it sprang, as well as the immediate object with which it was written. The Restoration found Dryden a literary adventurer, with a very slender patrimony and with no prospects. Poetry was a drug in the market; hack-work for the booksellers was not to his taste; and the only chance of remunerative employment open to him was to write for the stage. To this he accordingly betook himself. He began with comedy, and his comedy was a failure. He then betook himself to a species of drama, for which his parts and accomplishments were better fitted. Dryden had few or none of the qualifications essential in a great dramatist; but as a rhetorician, in the more comprehensive sense of the term, he was soon to be unrivalled. In the rhymed heroic plays, as they were called, he found just the sphere in which he was most qualified to excel. The taste for these dramas, which owed most to France and something to Italy and Spain, had come in with the Restoration. Their chief peculiarities were the complete subordination of the dramatic to the rhetorical element, the predominance of pageant, and the substitution of rhymed for blank verse. Dryden's first experiment in this drama was the _Rival Ladies_, in which the tragic portions are composed in rhyme, blank verse being reserved for the parts approaching comedy. In his next play, the _Indian Queen_, written in conjunction with Howard, blank verse is wholly discarded. The dedication of the _Rival Ladies_ to Orrery is appropriate. Roger Boyle, Baron Broghill, and first Earl of Orrery, was at this time Lord President of Munster, and it was he who had revived these rhymed plays in his _Henry V._, which was brought out in the same year as Dryden's comedy. Whoever has read this drama and Orrery's subsequent experiments, _Mustapha_ (1665), the _Black Prince_ (1667), _Tryphon_ (1668), will be able to estimate Dryden's absurd flattery at its proper value.