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 th