Mystery plays were religious dramas, intended to convey stories from the Bible to anaudience, and Byron followed this tradition in the development of a story related to thefratricide in Genesis when he wrote a dramatic poem called Cain, A Mystery (1821). AlthoughGoethe, Scott, and Shelley among others appreciated the publication of the work, there werenot a few critics who attacked the author harshly, regarding it as blasphemous. Even today thereis criticism that Byron projected his romantic thoughts into Lucifer and Cain, who rebelledagainst Jehovah. Whereas Milton’s main theme was to“ justify the ways of God to men,” didByron attempt to justify the ways of men to God, subverting the theology expressed in ParadiseLost?　　A sequel to the fall of Adam and Eve depicted in Paradise Lost, Cain deals with the secondfall of their eldest son in Eden where they and all their family, except Cain, are faithful to theirGod, worshipping Him in the appropriate ways. In Act 1, obsessed with his sense of loss andlonging for infinity and eternity, Cain is much moved by Lucifer’s discourse that the centre ofbeing is not God but one’s own self. In Act 2, by virtue of Lucifer’s supernatural power, the herofirst takes a flight through space before descending into Hades. Observing the vastness of theuniverse and the mightiness of the gigantic dead creatures that existed before mankind, Cain isoverwhelmed with his knowledge of the new pseudo-science and is tortured by the insignificanceof human life. Hearing from Lucifer the theory of deep thinking and endurance sends Cain intoa deep depression about his existence, but receives no hopeful vision or prospect from Lucifer.On returning to his home on Earth from the“ grand tour,” his family maintains the samecustoms of their native faith, of which he, superior to them in intelligence, cannot approve afterhis tutorials with his master Lucifer. Smarting from the rejection by God of his offerings of fruit,Cain flies into a rage and the infamous scene of bloodshed takes place. Horrified by what he hasdone, he comes to his senses, realising that he has taken his brother’s life. After his dialoguewith the Angel of the Lord, he is branded and banished to the wilderness outside Eden withAdah and their baby Enoch.　　The question is whether Byron identifies himself with Lucifer, Cain or someone elseentirely in the development of the dramatic poem outlined above. During his lifetime, theanonymous author of Uriel, A Poetical Address to Lord Byron (1822) criticised Byron forexpressing his blasphemous views through the characters in his play. Among the critics ofrecent years, Paul A. Cantor argues:“ . . . by identifying the orthodox God with the principle ofevil, Byron seems to justify revolution against established authority, and most of Cainaccordingly deals with the theme of the rebel against divine order” (1980, p. 55). Wolf Z. Hirstobserves that,“ Cain’s and Lucifer’s blasphemies echo the author’s own refusal to bow to thetraditional pieties mouthed by Adam and Abel” (1991, p. 90), although he acknowledges thatCain to some extent revises but does not ultimately reverse its model [i.e. the scripturalcontext] (p. 89). Paul Siegel sees Cain as“ one of those Byronic heroes who are a mereprojection of Byron himself.” (1941, p. 617) As for Cain, in Eggenschweiler’s view, after strikingAbel, although“ the character feels that he is no longer Cain, for us he has become the trueCain, the first murderer, the killer of his brother.” (1997, p. 244)　　In the beginning, the hero is characterised as a man seen in a mystery play, a dramaintended to convey the teachings of the Bible to illustrate masses during medieval times. He istorn between Adah, who wants him to stay with her, and Lucifer, the seducer who wants him tobe his follower. Although his intellectual faculty seems to be higher than that of his other familymembers, he is basically just a man who is exposed to the struggle between good and evil likeevery human being. In other words, he is typically a stock character called“ everyman” in thatkind of drama. After the horrific incident he undergoes a change from such a dramatic type intoa real person, as recorded in the Bible and as Eggenschweiler points out. Nevertheless, to myway of thinking, Cain returns to himself as a Byronic hero rather than a biblical figure.Rewriting the text of the Bible, the author presents him as someone who can claim audience’sempathy after the traumatic incident. Although Byron does not identify with the rebellious Cainbefore the murder, and much less with Lucifer, he is compassionate to the regenerated Cainafter the proclamation of his expulsion from Eden. One can note that, at the end of the poem,Cain has developed a better understanding of the world and himself than before, though he isstill stubborn at heart, and not a peaceful individual.　　Considering the above, we can arrive at the conclusion that Byron did not reverse thetheology of Milton, but vindicates the traditional faith just like the evangelical writers of oldentimes, who used mystery as a means of propagating their religion. Although Cain projects theagony of the modern mind into Byron’s work, we can nevertheless recognise the author’spurpose of advocating the“ sacred subject”: that God ultimately triumphs over the devil,frustrating the latter’s schemes. The irony is that, while seemingly representing stereotypicalromantic feelings, Byron actually distances himself from them in the poetical development. Heis, then, a cynic who takes a critical view of the literary scenes of his age. However, we shouldnot fail to recognise his serious intent to depict human agony in the play, dealing with“ thesacred theme” in the context of the 19th century England.