If good, why do I yield to that suggestion
     Whose horrid image doth unfix my hair
     And make my seated heart knock at my ribs,

would surely not be natural, even in Macbeth, if the idea of murder were already quite familiar to him through conversation with his wife, and if he had already done more than ‘yield’ to it.  It is not as if the Witches had told him that Duncan was coming to his house.  In that case the perception that the moment had come to execute a merely general design might well appal him.  But all that he hears is that he will one day be King—­a statement which, supposing this general design, would not point to any immediate action.[292] And, in the second place, it is hard to believe that, if Shakespeare really had imagined the murder planned and sworn to before the action of the play, he would have written the first six scenes in such a manner that practically all readers imagine quite another state of affairs, and continue to imagine it even after they have read in scene vii. the passage which is troubling us.  Is it likely, to put it otherwise, that his idea was one which nobody seems to have divined till late in the nineteenth century?  And for what possible reason could he refrain from making this idea clear to his audience, as he might so easily have done in the third scene?[293] It seems very much more likely that he himself imagined the matter as nearly all his readers do.

But, in that case, what are we to say of this passage?  I will answer first by explaining the way in which I understood it before I was aware that it had caused so much difficulty.  I supposed that an interview had taken place after scene v., a scene which shows Macbeth shrinking, and in which his last words were ‘we will speak further.’  In this interview, I supposed, his wife had so wrought upon him that he had at last yielded and pledged himself by oath to do the murder.  As for her statement that he had ‘broken the enterprise’ to her, I took it to refer to his letter to her,—­a letter written when time and place did not adhere, for he did not yet know that Duncan was coming to visit him.  In the letter he does not, of course, openly ‘break the enterprise’ to her, and it is not likely that he would do such a thing in a letter; but if they had had ambitious conversations, in which each felt that some half-formed guilty idea was floating in the mind of the other, she might naturally take the words of the letter as indicating much more than they said; and then in her passionate contempt at his hesitation, and her passionate eagerness to overcome it, she might easily accuse him, doubtless with exaggeration, and probably with conscious exaggeration, of having actually proposed the murder.  And Macbeth, knowing that when he wrote the letter he really had been thinking of murder, and indifferent to anything except the question whether murder should be done, would easily let her statement pass unchallenged.