That shake us nightly; better be with the dead."

In "Othello" is a striking picture of the sudden change, in the
direction we are considering, which comes over a tranquil mind from the
commission of a great crime. Iago says to Othello, after he has wrought
"the deed without a name":--

"Not poppy nor mandragora,
Nor all the drowsy syrups of the world,
Shall ever medicine thee to that sweet sleep
Which thou own'dst yesterday."

The greatest punishment which comes to Macbeth after the murder of
Duncan is lack of sleep. Nowhere in the language, in the same space, can
be found so many pictures of the blessedness of repose as in the
familiar lines:--

"Methought I heard a voice cry, 'Sleep no more!
Macbeth does murder sleep,' the innocent sleep;
Sleep that knits up the ravelled sleave of care,
The death of each day's life, sore labor's bath,
Balm of hurt minds, great Nature's second course,
Chief nourisher in life's feast."

And the principal reason which deters Hamlet from suicide is the fear
that even if he does sleep well "after life's fitful fever is over,"
still, that sleep may be full of troubled dreams.

"To sleep, perchance to dream. Ay, there's the rub;
For in that sleep of death what dreams may come