Scott disclaimed any special knowledge of stage-craft. "I know as little about the division of a drama as the spinster about the division of a battle, to use Iago's simile,"[114] he once wrote to a friend. Yet as a critic he had of course some general ideas about the making of plays, without having worked out any subtle theories on the subject. In criticising a play by Allan Cunningham, who had asked for his judgment on it, he remarked first that the plot was ill-combined. "If the mind can be kept upon one unbroken course of interest, the effect even in perusal is more gratifying. I have always considered this as the great secret in dramatic poetry, and conceive it one of the most difficult exercises of the invention possible, to conduct a story through five acts, developing it gradually in every scene, so as to keep up the attention, yet never till the very conclusion permitting the nature of the catastrophe to become visible,--and all the while to accompany this by the necessary delineation of character and beauty of language."[115] And again he said to the same person, "I hope you will make another dramatic attempt; and in that case I would strongly recommend that you should previously make a model or skeleton of your incidents, dividing them regularly into scenes and acts, so as to insure the dependence of one circumstance upon another, and the simplicity and union of your whole story."[116] Here we find Scott giving advice which by his own admission he was not himself able to follow in the composition of fiction. "I never could lay down a plan, or having laid it down I never could adhere to it," he wrote in his journal[117]. And the "Author" in the introductory epistle to _Nigel_ remarks, "It may pass for one good reason for not writing a play, that I cannot form a plot."