(b) Shakespeare also introduces the supernatural into some of his tragedies; he introduces ghosts, and witches who have supernatural knowledge.  This supernatural element certainly cannot in most cases, if in any, be explained away as an illusion in the mind of one of the characters.  And further, it does contribute to the action, and is in more than one instance an indispensable part of it:  so that to describe human character, with circumstances, as always the sole motive force in this action would be a serious error.  But the supernatural is always placed in the closest relation with character.  It gives a confirmation and a distinct form to inward movements already present and exerting an influence; to the sense of failure in Brutus, to the stifled workings of conscience in Richard, to the half-formed thought or the horrified memory of guilt in Macbeth, to suspicion in Hamlet.  Moreover, its influence is never of a compulsive kind.  It forms no more than an element, however important, in the problem which the hero has to face; and we are never allowed to feel that it has removed his capacity or responsibility for dealing with this problem.  So far indeed are we from feeling this, that many readers run to the opposite extreme, and openly or privately regard the supernatural as having nothing to do with the real interest of the play.

(c) Shakespeare, lastly, in most of his tragedies allows to ‘chance’ or ‘accident’ an appreciable influence at some point in the action.  Chance or accident here will be found, I think, to mean any occurrence (not supernatural, of course) which enters the dramatic sequence neither from the agency of a character, nor from the obvious surrounding circumstances.[3] It may be called an accident, in this sense, that Romeo never got the Friar’s message about the potion, and that Juliet did not awake from her long sleep a minute sooner; an accident that Edgar arrived at the prison just too late to save Cordelia’s life; an accident that Desdemona dropped her handkerchief at the most fatal of moments; an accident that the pirate ship attacked Hamlet’s ship, so that he was able to return forthwith to Denmark.  Now this operation of accident is a fact, and a prominent fact, of human life.  To exclude it wholly from tragedy, therefore, would be, we may say, to fail in truth.  And, besides, it is not merely a fact.  That men may start a course of events but can neither calculate nor control it, is a tragic fact.  The dramatist may use accident so as to make us feel this; and there are also other dramatic uses to which it may be put.  Shakespeare accordingly admits it.  On the other hand, any large admission of chance into the tragic sequence[4] would certainly weaken, and might destroy, the sense of the causal connection of character, deed, and catastrophe.  And Shakespeare really uses it very sparingly.  We seldom find ourselves exclaiming, ‘What an unlucky accident!’ I believe most readers would have to search painfully for instances.  It is, further, frequently easy to see the dramatic intention of an accident; and some things which look like accidents have really a connection with character, and are therefore not in the full sense accidents.  Finally, I believe it will be found that almost all the prominent accidents occur when the action is well advanced and the impression of the causal sequence is too firmly fixed to be impaired.