It is impossible to read Macbeth without being impressed by its repeated emphasis on the prevalence of evil forces in the world.  From the very start of the play an atmosphere of unnatural wickedness is established by the scene which opens with the stage direction Thunder and Lightening.  Enter Three Witches and ends with the reversal of values implied in ‘Fair is foul and foul is fair/ Hover through the fog and filthy air’.  In Macbeth, Shakespeare suggests a symbolic correspondence between three kinds of order:

• Order within the universe,
• Order within the commonwealth,
• Order within the human being.

The disruption of good order in the kingdom is paralleled by the disruption of nature, represented by the storm and the other portents on the night of Duncan’s murder, as well as by the appearance of the witches and of Banquo’s ghost; it has a further parallel in Lady Macbeth’s mental disintegration.  The savvy Elizabethan audiences were only too aware that portents of evil and evidence of disorder in one area were often mirrored by even greater disorders elsewhere.  The themes of unnatural doings, chaos in the natural world and universal disease are constantly suggested in the more memorable images.  Little wonder then that critics, when they come to talk about the impression created by the play, conclude that in none of the tragedies, with the possible exception of Lear, is evil presented so forcibly.  Macbeth has been described as Shakespeare’s ‘most profound and mature vision of evil’, ‘a wrestling of destruction with creation’, ‘a statement of evil’, and so forth.

If any one point is insistently made by the imagery it is that Macbeth’s revolt against lawful authority involves much more than the murder of a king and the usurpation of his throne.  The initial crime is a huge symbolic gesture.  It releases forces of universal disorder.  John Holloway talks of Macbeth’s career as one  ‘of revolt against everything in the world’ (The Story of the Night, 1961, p.61).  Once the first evil step has been taken there is no turning back: men and nature are caught up in a process which causes havoc everywhere until the evil forces have played themselves out.  Images of disease and unnatural happenings give concrete expression to the major themes.  The thought of his plan makes Macbeth’s heart knock at his ribs ‘against the use of nature’ (I, iii, 137); the dead Duncan looks like ‘a breach in nature’ (i.e. as if nature had been wounded by his death in II, iii, 95).  Lady Macbeth’s sleepwalking is described as a ‘great perturbation in nature’ (V, I, 9).  The murder of Duncan (‘the Lord’s anointed temple’ II, iii, 50) is explicitly and repeatedly presented as a monstrous violation of the natural order; it is committed when ‘nature seems dead’ (II, I, 50); in preparation for it Lady Macbeth invokes the aid of those murdering ministers who ‘wait on nature’s mischief’ (i.e. assist the malignant forces in nature and accompanying natural disasters: I, v, 48).  The association between Macbeth’s crime and disruption in nature is further emphasised in the comment on the odd behaviour of the elements following Duncan’s murder: ‘Tis unnatural/ Even like the deed that’s done’ (II, iv, 10).  The same kind of association between evil deeds and disorder within the individual is implied in the Doctor’s comment on Lady Macbeth’s sickness: ‘unnatural deeds/ Do breed unnatural troubles’ (V, I, 72).

The effects on his country and its people of Macbeth’s identification with evil are suggested in a series of disease images, which appear with particular frequency in the last Act.  The point made by these images is that Scotland is sick, and the cause of her disease is Macbeth’s criminal career.  Health and disease are symbolically related to moral good and evil.  Macbeth’s speech to the Doctor is an extended disease metaphor:

                   If thou couldst, doctor, sound

                   The sickness of my land, find her disease,

                   And purge it to a sound and pristine health….

                   What rhubarb, senna, or what purgative drug

                   Would scour these English hence?

                                                                             V, v, 50

It is in relation to this kind of speech that the descriptions of the King’s Evil (IV, iii, 141 – 159) takes on its true importance.  At the hands of the good English king, diseased souls ‘presently amend’ (IV, iii, 138).  At Macbeth’s hands, ‘good men’s lives/ Expire before flowers in their caps,/ Dying or ere they sicken’ (IV, iii, 164).  Macbeth’s cause is ‘distemper’d’ (V, ii, 15).  Malcolm is to be the physician who will heal Scotland: ‘Sovereign’ as used by Lennox means both ‘royal’ and ‘powerfully medicinal’:

          Caithness:     Meet we the medicine of the sickly weal,

                              And with him pour we, in our country’s purge,

                              Each drop of us.

          Lennox:         Or so much as it needs,

   To dew the sovereign flower and drown the weeds.

                                                                                                V, ii, 26

The play depicts the restoration of order as well as its violation.  A whole society is disordered and sickly (‘Bleed, bleed poor country!’ Iv, iii, 32), and the order of nature has been disrupted.  Macbeth’s famous catalogue of dogs (III, I, 91) emphasises the idea of a proper order among animals as well as men; it is a fine stroke of irony on Shakespeare’s part to make the prime enemy of order concede its propriety.  The third movement of the play (which belongs to Malcolm and Macduff in the way that the first did to Duncan and the second to Banquo), shows violated nature preparing itself to put an end to the unnatural disintegration set in train by Macbeth’s acts, the process by which ‘the treasure/ Of nature’s germens tumble all together,/ Even till destruction sicken’ (IV, I, 58).  As Macbeth’s power begins to wane, supernatural aid is invoked on behalf of those who would restore the beneficent order of nature (‘the Powers above/ Put on their instruments…’ IV, iii, 231). The movement of Birnam Wood towards Dunsinane (V, iv, 4) is a vivid emblem of the reassertion of the natural order, ‘a dumbshow of nature overturning anti-nature at the climax of the play’ (John Holloway, op. cit., p.65).

It needs to be emphasised that while Shakespeare makes extensive use of religious, even specifically Christian images and ideas throughout Macbeth (see particularly Iv, iii), this does not mean that the play reaches ‘optimistic’ conclusions about its themes, or that it was written to suggest the superiority of a Christian view of life and action.  We should restrain any tendency we may feel to treat the major characters as diagrammatic illustrations of ‘good’ and ‘evil’ tendencies.  Shakespeare poses too many unanswered questions for us to be able to regard Macbeth as a celebration of the triumph of good over evil; like all genuine tragedies, it maintains a balance of vision.  An element of painful mystery remains even after the fragile triumph of the official forces of good order.  This is well described by Robert Ornstein:

‘If the anguish of the damned sounds musically in the ears of the saved, then there is comfort here for some; otherwise Macbeth is the most unpleasant of the tragedies.  Though order is restored at the close, though evil is purged and Macbeth receives the gift of oblivion, there is no sense of repose or reconciliation in its final scenes’ (The Moral Vision of Jacobean Tragedy, 1960).

Order is restored, as Ornstein points out; a ‘good’ regime is to replace an evil one, but what we have seen happen in Macbeth leaves us with the feeling that destructive forces can just as easily erupt again, and with similar consequences.  It is difficult to see the closing ‘restoration’ as anything more than provisional.  The final speeches of the ‘good’ characters, with their promises of better things to come lack the emotional weight necessary to dispel the gloomy visions conjured up by the Macbeths and their allies. In the Irish political context, this is, in fact, akin to Fine Gael, Fianna Fáil, Labour, The Greens, etc., telling us they will right all the wrongs of the previous Fine Gael,  Fianna Fáil/Progressive Democrats administration.  We all know by now from bitter experience that these election promises are often made to sound very hollow in time!