The law of the unities does not receive such rigid application in England as is given by Sidney until the introduction of the French influence nearly three quarters of a century later. Ben Jonson is considerably less stringent in this respect than Sidney. He lays particular stress on the unity of action, and in the _Discoveries_ explains at length the Aristotelian conception of the unity and magnitude of the fable. "The fable is called the imitation of one entire and perfect action, whose parts are so joined and knit together, as nothing in the structure can be changed, or taken away, without impairing or troubling the whole, of which there is a proportionable magnitude in the members."[525] Simplicity, then, should be one of the chief characteristics of the action, and nothing receives so much of Jonson's censure as "monstrous and forced action."[526] As to the unity of time, Jonson says that the action should be allowed to grow until necessity demands a conclusion; the argument, however, should not exceed the compass of one day, but should be large enough to allow place for digressions and episodes, which are to the fable what furniture is to a house.[527] Jonson does not formally require the observance of the unity of place, and even acknowledges having disregarded it in his own plays; but he does not favor much change of scene on the stage. In the prologue of _Volpone_, he boasts that he has followed all the laws of refined comedy, "As best critics have designed; The laws of time, place, persons he observeth, From no needful rule he swerveth." Milton observes the unity of time in the _Samson Agonistes_: "The circumscription of time, wherein the whole drama begins and ends is, according to ancient rule and best example, within the space of twenty-four hours." With the introduction of the French influence, the unities became fixed requirements of the English drama, and remained so for over a century. Sir Robert Howard, in the preface of his tragedy, _The Duke of Lerma_, impugned their force and authority; but Dryden, in answering him, pointed out that to attack the unities is really to contend against Aristotle, Horace, Ben Jonson, and Corneille.[528] Farquhar, however, in his _Discourse upon Comedy_ (1702), argued with force and wit against the unities of time and place, and scoffed at all the legislators of Parnassus, ancient and modern,--Aristotle, Horace, Scaliger, Vossius, Heinsius, D'Aubignac, and Rapin. IV. _Epic Poetry_