In Act V, scene v, of Macbeth, what is the main idea of Macbeth's soliloquy after hearing his wife has died?
In Shakespeare's Macbeth, Macbeth delivers his famous "Tomorrow, and tomorrow" speech in Act V, following his wife's suicide.
When the reader first sees Macbeth and Lady Macbeth together for the first time in Act I, though she is harsh and overbearing, they share sentiments that speak of a genuine affection for one another. Ironically, where Macbeth is squeamish about murdering Duncan, and Lady Macbeth has no qualms at all, as the story progresses, the blood they shed weighs heavily on Lady Macbeth's heart and mind, while Macbeth embraces the tyrant's role, murdering more often, and seemingly, with more ease.
By the time the end of the play nears, Lady Macbeth has gone mad, walking in her sleep, and repeating conversations that prove the she and Macbeth were complicit in a long list of murders. Macbeth still is concerned for his wife, asking the Doctor to do something for her.
When Macbeth learns of his wife's suicide, it is important to remember that he is growing tired of the killing and the disappointment of wanting something (the throne) and finding little joy in the having of it. His thanes are not only deserting him, but are joining the other side to fight against him. In Act V, scene iii, Macbeth bemoans the fact that he is tired of his life:
I have lived long enough. (22)
He notes that as he ages, so much more quickly now it seems, that he has no group of friends to keep him company, no honor or love—
...but in their stead,
Curses, not loud but deep, mouth honor, breath,
Which the poor heart would fain deny, and dare not. (26-28)
By the time he hears of Lady Macbeth's death, Macbeth has begun to lose faith. He looks at life as a collection of meaningless actions:
And all our yesterdays have lighted fools
The way to dusty death. (22-23)
In other words, everyone ends up in the same situation: dead.
The famous line, "Out, out, brief candle!", refers to the brevity of life. He describes each person as one who, like a player on the stage, acts and speaks his lines, but it is all meaningless in the end, and forgotten.
It is a tale
Told by an idiot, full of sound and fury
Signifying nothing. (26-28)
Perhaps we can assume that after all that Macbeth has done to gain the throne and keep it, he finds it of little value, not worth sacrificing his immortal soul. (He murdered a King, a sin against God.) It would appear that being King no longer brings him pleasure.
Macbeth realizes that life is short, and facing his mortality, it seems that he finds that all he has done, in the end—in the face of certain death—is unimportant. Had there been any doubt in his mind before, Lady Macbeth's death leaves him completely alone in the world.
You have selected perhaps one of the most famous speeches out of this great play. The news of his wife's death forces Macbeth to confront certain realities about his position that he has up until now successfully ignored, but let us see what he says in full:
Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day,
To the last syllable of recorded time;
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life's but a walking shadow; a poor player,
That struts and frets his hour upon the stage,
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Wow! Profound words! In this speech therefore Macbeth expresses the hopelessness of the situation of a hardened sinner to whom the universe has no meaning. Note how Macbeth expresses his nihilism, saying that life "signifies nothing" and that all of our actions are as if they were a tale "told by an idiot" and "full of sound and fury." As he says the famous words, "out, out, brief candle," Macbeth perhaps bids farewell to his wife but also accepts the doom that awaits him and the end of his brief and pointless life.
It is incredibly important to note that it is after delivering this soliloquy that Macbeth receives news of the prophecy that marks his end: Burnham wood is apparently coming to Dunsinane, making his moment of self-epiphany particularly poignant.