Shakespeare uses the character of Macduff largely as a foil to show the shortcomings of his tragic hero Macbeth. He is a man of great integrity yet he is portrayed as very one-dimensional in the play. He is also a man of ‘high degree’, a Thane and as such he represents a role of freely given allegiance and service to his King. He is without any vestige of personal ambition and is simply content to loyally serve Duncan, his King.

It is Macduff who is the first of the innocent bystanders to discover the fact that Duncan has been murdered. His reaction is one of horror at the sight of Duncan’s body and it conveys clearly his profound sense of the sacredness of majesty, of that ‘divinity that doth hedge a king.’ This emphasises for us the enormity of what has just happened and that the murder of a king is no ordinary crime. To Macduff, Duncan’s murder seems like the ‘great doom’s image’, it signals the end of the world as he had known it.

‘Confusion now hath made his masterpiece!
Most sacrilegious murder has broke ope
The lord’s anointed temple, and stole thence
The life o’ the building.’

We realise from the beginning that Macduff would never be capable of the equivocation that Macbeth has already begun the master following the death of Duncan. This sense of integrity and loyalty is further ratified when we learn that he will not make the journey to Scone to see Macbeth crowned. It is clear that he is already suspicious of the man who is going to succeed Duncan as king, and that he is not prepared to feign a loyalty he does not feel.

‘Well may you see things well done there…
Lest our old robes sit easier than our new’.

An important aspect of Macduff’s role is now already becoming clear at this stage of the play: he is to be seen as the principled dissenter, too honest and too sincerely concerned with Scotland’s welfare to be capable of giving unquestioning allegiance to the new regime under Macbeth. Macduff’s moral courage and ‘manliness’ is shown in the fact that he takes a stance against Macbeth at a time when even Banquo has remained silent.
The next time we hear about Macduff in the play is when he goes to England to interview Malcolm who is Duncan’s son and rightful heir to the throne of Scotland. Lennox tells us in Act IV Scene i that ‘Macduff is fled to England’. He goes there to plead with Malcolm to return to Scotland and restore order and legitimate rule there. It is clearly evident that Macduff’s role has become much more significant in terms of the play’s plot. He is emerging as a pivotal character, a king-maker, in mobilising the forces for good against Macbeth’s corrupt rule. As Act IV progresses, we begin to realise that Macbeth is threatened by the existence of Macduff because he is a respected and mature figure among the Scottish Thanes. The issue of manliness is an important one here. Shakespeare seems to want us to understand, through the principled stance of Macduff, that a single brave man’s opposition can have an effect even in the face of the barefaced exercise of tyrannical power.

Macbeth, it is clear, is not surprised when the first apparition tells him ‘to beware Macduff’, and he comments ‘Thou has harped my fear aright.’ When he hears of Macduff’s flight to England, in an act of temper and fury, he decides to wipe out his enemy’s family as a proxy for Macduff himself. Thus, in a fit of insanely misdirected violence, Macbeth commits a crime against the innocent and uninvolved. In this act of gratuitous violence, he alienates the audience from himself as no other of his earlier crimes have done.

Macduff in deciding to go to England has had to choose between the safety of his family and the safety of his country. Thus Macduff, in being true to Scotland, seems, to his own wife, to be a traitor.

‘To leave his wife, his babes … in a place
From whence himself does fly?
He loves us not, he wants the natural touch.’

Later on, Macduff himself will exclaim with a bitter sense of guilt:

‘Sinful Macduff! They were all struck for thee.’

When we encounter Macduff in England in Act IV Scene iii we again see him in the role of practical patriot seeking to encourage Malcolm to take up arms against Macbeth:

‘Hold fast the mortal sword …
Bestride our downfall’n birthdom.’

In this powerful scene Shakespeare also seems to use Macduff as a spokesperson for suffering Scotland:

‘Each new morn
New widows howl, new orphans cry; new sorrows
Strike heaven on the face… ‘

Macduff’s patriotism is severely tested by Malcolm. Despite the false catalogue of sins which Malcolm claims to have committed, Macduff is too honest and too principled a man to be able to take any more, ‘Fit to govern?’ he exclaims angrily and concludes ‘No, not to live.’ Turning away in misery and despair his thoughts turn towards Scotland:

‘O nation miserable, with an untitled tyrant bloody-sceptered
When shalt thou see thy wholesome days again?’

Once again, it has been made clear in the play that Macduff’s dominant quality is his blunt honesty. This man could never have hung about Macbeth’s court paying him ‘mouth honour’ as many have been doing up to now. The equivocation and hypocrisy associated with the world of evil would always have been alien to this man’s nature.
When he learns shortly after this about the death of his wife and all his children Macduff is shown at his most affectingly human and paradoxically also at his most manly. He cries out in agony:

‘All my pretty ones? O hell kite
Did you say all? All?
What all my pretty chickens and their dam
At one fell swoop?’

When Malcolm tells him to ‘Dispute it like a man,’ he replies in a tone of quiet dignity and telling rebuke:

‘I shall do so
But I must also feel it as a man
I cannot but remember such things were
That were most precious to me.’

Here, at this point, we cannot but recall Lady Macbeth’s words earlier and of her resolve to dash her baby’s brains out rather than be forsworn. Here, through Macduff, Shakespeare is reminding us that true manliness is not divorced from feelings or diminished by tears.

What follows is Macduff’s determination to bring Macbeth to justice:

‘Front to front
Bring on this fiend of Scotland and myself
Within my sword’s length; if he ‘scape
Heaven forgive him too.’

Macduff is now aware of only one solemn religious duty which is the elimination of Macbeth. When he and Macbeth finally meet, it becomes obvious that we are intended to see Macduff as the instrument of divine retribution. His sense of duty is uppermost in his mind right up to the end:

‘If thou beest not slain and with no stroke of mine
My wife and children’s ghosts will haunt me still.’

The irony of Macbeth’s end is that he is killed by a man whose birth was rationally impossible; Macduff was from his mother’s womb ‘untimely ripp’d.’ Yet the man confronting Macbeth is undeniably real and undeniably ‘manly’. It is therefore appropriate that Macbeth would be ‘unmanned’ by what he has just heard:

‘It hath cowed my better part of man.’
Only now does he realise that the witches were truly ‘juggling fiends that palter with us in a double sense.’

Macbeth’s death at the hands of Macduff now becomes inevitable, as he himself and the audience are fully aware. It is appropriate that at the play’s conclusion it should be left to Macduff the unswerving and selfless patriot, the unassuming manly warrior, the man of absolute integrity to proclaim Malcolm as rightful king and announce at last that Scotland is liberated from tyranny:

‘The time is free.’

In the case of Macduff, Shakespeare has ensured that at every stage in the plot Macduff is credibly human. This was important in the context of this play’s emphasis on the terrifying and real power of evil. Shakespeare reminds us here through his depiction of Macduff that even when a country is enslaved to tyranny and subjected to a reign of terror, a single honest man by his refusal to compromise and by his principled and morally courageous dissent can be seen for what he is, and can certainly make a difference.