In the address, "Of that Sort of Dramatic Poem which is called Tragedy," prefixed to _Samson Agonistes_, Milton has minutely adhered to the Italian theory of tragedy. After referring to the ancient dignity and moral effect of tragedy,[513] Milton acknowledges that, in the modelling of his poem, he has followed the ancients and the Italians as of greatest authority in such matters. He has avoided the introduction of trivial and vulgar persons and the intermingling of comic and tragic elements; he has used the chorus, and has observed the laws of verisimilitude and decorum. His explanation of the peculiar effect of tragedy--the purgation of pity and fear--has already been referred to in the first section of this essay.[514] II. _Comedy_ The Elizabethan theory of comedy was based on the body of rules and observations which the Italian critics, aided by a few hints from Aristotle, had deduced from the practice of Plautus and Terence. It will, therefore, be unnecessary to dwell at any great length on the doctrines of Sidney and Ben Jonson, who are the main comic theorists of this period. Sidney defines comedy as "an imitation of the common errors of our life," which are represented in the most ridiculous and scornful manner, so that the spectator is anxious to avoid such errors himself. Comedy, therefore, shows the "filthiness of evil," but only in "our private and domestical matters."[515] It should aim at being wholly delightful, just as tragedy should be maintained by a well-raised admiration. Delight is thus the first requirement of comedy; but the English comic writers err in thinking that delight cannot be obtained without laughter, whereas laughter is neither an essential cause nor an essential effect of delight. Sidney then distinguishes delight from laughter almost exactly after the manner of Trissino.[516] The great fault of English comedy is that it stirs laughter concerning things that are sinful, _i.e._ execrable rather than merely ridiculous--forbidden plainly, according to Sidney, by Aristotle himself--and concerning things that are miserable, and rather to be pitied than scorned. Comedy should not only produce delightful laughter, but mixed with it that delightful teaching which is the end of all poetry. Ben Jonson, like Sidney, makes human follies or errors the themes of comedy, which should be "an image of the times, And sport with human follies, not with crimes, Except we make them such, by loving still Our popular errors, when we know they're ill; I mean such errors as you'll all confess By laughing at them, they deserve no less."[517]