Goethe's comment on reading and reviewing _Cain_ was that he should be surprised if Byron did not pursue the treatment of such "biblical subjects," as the destruction of Sodom and Gomorrah (_Conversations, etc._, 1879, p. 62); and, many years after, he told Crabb Robinson (_Diary_, 1869, ii. 435) that Byron should have lived "to execute his vocation ... to dramatize the Old Testament." He was better equipped for such a task than might have been imagined. A Scottish schoolboy, "from a child he had known the Scriptures," and, as his _Hebrew Melodies_ testify, he was not unwilling to turn to the Bible as a source of poetic inspiration. Moreover, he was born with the religious temperament. Questions "of Providence, foreknowledge, will and fate," exercised his curiosity because they appealed to his imagination and moved his spirit. He was eager to plunge into controversy with friends and advisers who challenged or rebuked him, Hodgson, for instance, or Dallas; and he responded with remarkable amenity to the strictures and exhortations of such orthodox professors as Mr. Sheppard and Dr. Kennedy. He was, no doubt, from first to last a _heretic_, impatient, not to say contemptuous, of authority, but he was by no means indifferent to religion altogether. To "argue about it and about" was a necessity, if not an agreeable relief, to his intellectual energies. It would appear from the Ravenna diary (January 28, 1821, _Letters_, 1901, v. 190,191), that the conception of Lucifer was working in his brain before the "tragedy of Cain" was actually begun. He had been recording a "thought" which had come to him, that "at the very height of human desire and pleasure, a certain sense of doubt and sorrow"--an _amari aliquid_ which links the future to the past, and so blots out the present--"mingles with our bliss," making it of none effect, and, by way of moral or corollary to his soliloquy, he adds three lines of verse headed, "Thought for a speech of Lucifer in the Tragedy of _Cain_"-- "Were Death an _Evil_, would _I_ let thee live? Fool! live as I live--as thy father lives, And thy son's sons shall live for evermore." In these three lines, which were not inserted in the play, and in the preceding "thought," we have the key-note to _Cain_. "Man walketh in a vain shadow"--a shadow which he can never overtake, the shadow of an eternally postponed fruition. With a being capable of infinite satisfaction, he is doomed to realize failure in attainment. In all that is best and most enjoyable, "the rapturous moment and the placid hour," there is a foretaste of "Death the Unknown"! The tragedy of _Manfred_ lies in remorse for the inevitable past; the tragedy of _Cain_, in revolt against the limitations of the inexorable present.